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WSET Level 4 D1 Wine Production > Common Winemaking Options > Flashcards

Common Winemaking Options Flashcards

1
Q

What are the main components of wine?

A

Water (85%)
Residual Sugar
Alcohol (11%)
Glycerol
Acid
Phenolics
Aromatics

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2
Q

Describe water, which is one of the main components of wine.

A

Wine is approx. 85% water by volume, depending on abv, level of RS and other factors.
Water is critical for the way a wine flows as a liquid.

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3
Q

What are the EU classification of sweetness levels?

A

Dry/sec/trocken
Medium dry/demi-sec/halbtrocken
Medium or medium sweet/moelleux/lieblich
Sweet/doux/suss

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4
Q

What are the sweetness levels for dry wines

A

Up to 4 g/L, or not exceeding 9 g/L provided total acidity expressed as grapes of tartaric acid per litre is not more than 2 g below RS content.
Wine with 9 g/L can be labelled as Sec if it has 7 g/L total acidity.

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5
Q

What are the sweetness levels for medium dry wines

A

4-12 g/L, or up to 18 g/L provided total acidity expressed as grams of tartaric acid per litre is not more than 10g below the RS content

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6
Q

What are the sweetness levels for medium or medium sweet wines

A

12-45 g/L

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7
Q

What are the sweetness levels for sweet wines

A

At least 45 g/L

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8
Q

Describe alcohol, which is one of the main components of wine

A

Ethanol is formed during fermentation and is predominant alcohol in wine. It has slightly sweet smell. It contributes a sense of sweetness and bitterness, and oral warmth. It also contributes fullness to the body of wine and mouthfeel.
Alcohol levels of 14.5% and above reduce volatility of wine aromas and increase sense of bitterness.
Wines with high alcohol levels must have sufficient fruit concentration to be in balance with alcohol.
Traces of higher alcohols, but these are below level of perception.

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9
Q

Describe glycerol, which is one of the components of wine

A

Glycerol is the 3rd most abundant part of wine after water and alcohol and derived from sugar in grapes. It occurs in higher levels in wines made from botrytis-affected grapes (Tokaji) and wines made by carbonic maceration (Beaujolais), but lesser extent than those made from botrytis-affected grapes.
Contributes smoothness to texture of wine and perception of fullness of the body.
Has slightly sweet taste.

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10
Q

What are the principle and secondary acids in wine

A

Principle - tartaric, malic - come from grapes
Secondary - lactic (MLC), acetic (fermentation)

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11
Q

Describe what volatile acidity is

A

Volatile acidity refers to acetic acid (vinegar smell). Some other compounds can contribute. It is present in all wines, but generally at low concentrations. It is only a fault in excess.
Acetic acid reacts with alcohol in wine and becomes ethyl acetate (nail polish remover). This is perceived as a fault in excess.

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12
Q

What are the total acidity and pH ranges in wine

A

Total acidity - 5.5-8.5 g/L
pH - 3-4

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13
Q

Describe what phenolic compounds are

A

Phenolic compounds are important group of compounds that occur in grape skins, stems and seeds.
Includes anthocyanins (colour pigments in red wines - sometimes blue tints of red and rose wines) and tannins
Tannins bind with proteins in mouth, giving drying sensation on palate
Tannins react with other compounds in wine during winemaking/maturation, changing their composition and how they are perceived.
Unripe tannins taste bitter.
A little RS can make tannins seem softer; dry wines with high acidity can make tannins more astringent

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14
Q

What are the 4 sources of aromatic and non-aromatic compounds in wine

A

Aromas from grapes
Aromas created by fermentation due to presence of aroma precursors in grape must
Aromas originating from fermentation and its by-products
Aromas from other sources - vanillin from oak barrels, eucalyptol

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15
Q

What are examples of aromas from grapes

A

Methoxypyrazines - Sauvignon Blanc - grassy, green pepper aroma
Rotundone - Syrah, Gruner Veltliner - pepper aroma

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16
Q

What are examples of aroma compounds created by fermentation due to the presence of aroma precursors in grape must

A

Thiols - category of aromatic compounds released during fermentation - 4MMP - box tree aromas in Sauvignon Blanc
Terpenes - category of aromatic compounds - gives fruity/floral aromas. Examples are linalool and geraniol that contribute to grapey aromas/flavours in Muscat

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17
Q

What are examples of aromas originating from fermentation and its by-products

A

Esters
Acetaldehyde
Diacetyl

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18
Q

Describe what esters are

A

Esters are compounds formed by reaction of certain acids and alcohols. Majority created through action of yeasts in fermentation process.
Provides fresh/fruity aromas - essential in aroma profiles of young white wines
Most common is isoamyl acetate - gives aroma of banana (Beaujolais) when high; also apple, pineapple
Ethyl acetate - another common ester.
Most esters are unstable and break down a few months after fermentation.

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19
Q

Describe what acetaldehyde is

A

Acetaldehyde is an aroma that occurs in wines due to the oxidation of ethanol (ethanal).
Masks fresh fruit aromas and has stale smell that is regarded as a fault in wines.
Is an important component of the distinctive aroma of Fino sherry.

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20
Q

Describe what diacetyl is

A

Diacetyl is produced during fermentation and MLC. It contributes a buttery aroma.

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21
Q

List the main winemaking approaches

A

Conventional
Organic
Biodynamic
Natural

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22
Q

Describe what conventional winemaking is

A

Aim of conventional winemaking is to produce stable wines which reliably show their fruit character and have no faults.
Conventional winemaking includes:
Temp control - ability to control temp is a factor in following areas: cold soaking, fermentation, maturation
Use of additives and/or processing aids - add sugar to increase potential alcohol or sweeten final wine, add SO2 to protect wine, cultured yeast, fining agents
Manipulations - from simple pressing and filtration to high technology reverse osmosis

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23
Q

Describe what organic winemaking is

A

Organic winemaking includes making wine with certified organically grown grapes and complying with rules that restrict certain practices from being performed during winemaking.
Many additives/processes used in conventional are allowed - cultured yeasts, yeast nutrients, adding tannins - Ecocert - certification agency - full list of allowable additives and processes.
Certification adds a small cost element to organic wines. Wines sold at very price level.

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24
Q

Describe what biodynamic winemaking is

A

Certified biodynamic wine must be made from certified biodynamically grown grapes.
In winery, certain processes required or encouraged by certifying body Demeter Int’l
Demeter sets global standards, but certifiers in each country determine specification for that country
Many products not permitted - adding tannins or certain fining agents such as isinglass
Certification adds small cost; wines usually mid-priced and above, reflecting additional costs and small-scale production

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25
Q

Describe what natural winemaking is

A

Natural winemaking rejects modern interventions in favour of artisan practices from the past. Aim is ‘nothing added, nothing removed’
Wine made with fewest possible manipulations - low-intervention winemaking)
Organic or biodynamic grapes should be used.

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26
Q

Describe the advantages and disadvantages of conventional winemaking

A

Advantages
Consistent and predictable product
Efficient way to keep pests and diseases away from vineyard
Disadvantages
Environmental impact - synthetic pesticides, herbicides, fertilizers can harm soil health, water quality and wildlife habitats
Health impact -synthetic pesticides, herbicides, fertilizers are unhealthy for people working in vineyards
Compromises terroir - synthetic inputs can compromise the expression of terroir.

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27
Q

Describe the advantages of organic and biodynamic winemaking

A

Fewer additives - fewer synthetic additives and preservatives
Purer product - natural product with fewer chemical residues
Healthier vineyard ecosystem - promotes biodiversity and a healthier vineyard ecosystem
Fewer sulphites - contains around half the amount of sulphites found in regular wines
More flavourful - more flavour because of quality of soil and lack of chemical farming

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28
Q

Describe the disadvantages of organic and biodynamic winemaking

A

Smaller harvest - organic farming is labour-intensive and often yields are smaller
Shorter shelf life - organic wines may have shorter shelf life due to lower sulfur content
More expensive - organic wines can be pricier due to the smaller harvest and labour-intensive farming

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29
Q

Describe the advantages of natural winemaking

A

Taste - natural wine tastes better than conventional wine
Health - natural wine is healthier for you, less chemicals
Environmental impact - a product of sustainable viticulture
Natural winemaker is a artisan

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30
Q

Describe the disadvantages of natural winemaking

A

Inconsistency - natural wine is different each year
Availability - it isn’t mass-produced
Serving - some natural wines need to be opened several hours before served
Storage - natural wines need to be stored more carefully
Natural wine needs careful transportation - kept below 14 degrees at all times - more costly to transport

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31
Q

What are the negative effects of oxygen

A

Oxygen is generally threatening for production of fresh, fruity wines.
There is a loss of fruitiness and unwanted aromas
Change in colour - white wines turn darker (gold, then brown)
Bacterial spoilage

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32
Q

What can be done to avoid the negative effects of oxygen

A

Avoid excessive ullages
Inert gas blanketing - nitrogen, carbon dioxide, argon
Impermeable containers - SS, thick concrete, wooden vessels allow gentle ingress of oxygen
Reduced temperatures - cool, constant temps slow rate of oxidation
Addition of SO2 - strong anti-oxidative effects

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33
Q

What is sulfur dioxide, how is it used in winemaking and what are the properties

A

Sulfur dioxide is a preservative used in winemaking that has the following properties:
Anti-oxidant - it reduces effects of oxidation by reacting with products of oxidation reactions, so they cannot oxidize further compounds in wine. It inhibits oxidative enzymes.
Anti-microbial - it inhibits the development of microbes such as yeast and bacteria. Different species of yeast and bacteria can vary in their tolerance to SO2

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34
Q

Describe measures that can be taken to minimize the threats of oxidation and microbial infection while grapes are being transported to the winery

A

Harvesting/transporting at night when temps are low or harvesting at sunrise if harvesting by hand
Addition of SO2 for its anti-oxidant and anti-microbial properties at time of harvesting
Reduction of grapes’ temp by putting them in cold storage room once received at winery
Sanitizing harvesting equipment/bins
Collecting and transporting grapes in small crates minimizes crushing

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35
Q

When grapes arrive at the winery, what are the winemaking options

A

Chilling
Sorting
Destemming
Crushing

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36
Q

At grape reception at the winery, describe the chilling winemaking process

A

If grapes are warm when they reach winery, may choose to chill them to a lower temp before crushing and pressing begins. Warm temps lead to increased oxidation and spoilage organisms.
Chilling grapes takes place in a refrigeration unit. This takes time and may slow processing of grapes.
A heat exchanger can be used for chilling if grapes in a more fluid format - this works more quickly
Both options incur costs in terms of equipment and energy.
Harvest at night or early in morning is encouraged in warm climates to bring in cool grapes and avoid these costs

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37
Q

At grape reception at the winery, describe the sorting winemaking process

A

French term = triage
Whether sorting is needed depends on ripeness and health of fruit arriving at winery, intended final quality and price, if grapes were sorted in vineyard and physical state of grapes.
The more sorting carried out, the higher the cost. Judgment needs to be made to level of sorting that is justifiable in relation to return on sale of wine
Can remove unwanted grapes before picking or during harvesting
Sort by hand on table - can take place before or after destemming; occasionally before & after destemming
Optical sorting uses digital imaging and software to scan grapes

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38
Q

At grape reception at the winery, describe the destemming winemaking process

A

Hand harvested grapes are destemmed on arrival at winery. Machine harvested are already destemmed.
Destemmers work by series of blades within a rotating drum that removes grapes from stems.
Stems contain tannins - generally unwanted in white wines. If stems not ripe, they add unwanted green flavours and bitter tannins to wine.
Grapes are not destemmed in following situations:
Red wine fermentations using whole bunches
Carbonic maceration
Whole bunch pressing for some white wines (common for high-quality sparkling wines)

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39
Q

At grape reception at the winery, describe the crushing winemaking process

A

Application of sufficient pressure to grapes to break the skins and release the juice, making it available for fermentation. Pressure applied needs to be gentle enough not to crush seeds - would add bitterness.
Many wineries combine destemming/crushing in a destemmer-crusher machine
Output is called must - mixture of grape juice, pulp, skins and seeds

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40
Q

Describe the pressing winemaking process

A

In white winemaking - grapes pressed to extract juice from grapes and separate skins from juice before fermentation. Aim is to crush and press berries to maximize release of juice without extracting tannins from skins and seeds and avoid excessive amounts of solids.
In red winemaking, grapes crushed before fermentation and pressed after desired number of days on skins or at end of fermentation. Pressing usually after fermentation has been completed. Care taken not to extract excess tannin and bitterness from skin and seeds.

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41
Q

List the different types of presses that can be used for pressing wine

A

Pneumatic press
Basket press
Horizontal press
Continuous press

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42
Q

Describe how pneumatic presses work

A

Pneumatic presses are the most popular and are also called air bag presses. Press made up of a cylindrical cage with a bladder that runs down the side or middle. Grapes loaded into tank. Other side of cage filled with air, and as bladder inflates, grapes gradually pushed against grates on side of cage, separating juice or wine from skins.
Advantages - can be programmed to exert different amounts of pressure; can be flushed with inert gas to prevent oxidation.

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43
Q

Describe how basket presses work

A

More traditional form of presses. Also called vertical or champagne presses.
Basket is filled with grapes and pressure applied from above. Juice/wine runs through gaps or holes in side of basket and collected in a tray at the bottom.
Pipe transfers juice/wine to another vessel.
Not a sealed vessel, so cannot be flushed with inert gas to avoid oxygen exposure.
Some believe this is gentler than pneumatic presses.
Holds smaller load, more labour intensive. Best suited for small wineries making premium wine.

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44
Q

Describe how horizontal screw presses work

A

Horizontal screw presses are similar to basket presses but mounted horizontally above rectangular draining tray. Less gentle and less popular.
Requires batch processing.
Grapes loaded into press, they are pressed, skins removed and press needs to be cleaned before next batch can be loaded - this takes time.

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45
Q

Describe how continuous presses work

A

Continuous presses allow grapes to be continually loaded into press as it works by using a screw mechanism. Allows for quicker pressing of large volumes of grapes.
Less gentle than pneumatic and basket presses.
Best suited for high-volumes of inexpensive wines.

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46
Q

Describe how modern presses work

A

Modern presses are computerized. Winemakers program the pressure and length of each press cycle.

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47
Q

Describe what free run juice and press juice are

A

Free run juice - if grapes destemmed/crushed, the juice that is drained off as soon as the grapes are crushed. Juice with lowest solids, tannin & colour. Lower in pH and higher in acidity.

Press juice - Juice that runs off through the pressing process. At start, press juice is similar to free run juice, but as pressing continues, more solids, tannins and colour are extracted. Lower in acidity, less sugar.

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48
Q

List the different types of pre-fermentation adjustments that can be made to must

A

Increasing Potential alcohol
Acidification
Deacidification
Enrichment
Reducing Alcohol
Adding Tannins

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49
Q

Describe what potential alcohol is

A

Potential alcohol is the amount of alcohol that would be created by fermenting all naturally occurring sugar in must into alcohol.

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50
Q

Describe why acidification would be done.

A

In warm climates without cooling influences, malic acid drops quickly in grapes as they ripen. If wine not acidified, it could lack freshness. Could also be used to lower pH.
Routine in warmer climates for inexpensive and mid-priced wines and many premium wines.
Can take place before, during or after fermentation.

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51
Q

List the acids that can be added to must as part of the acidification process

A

Tartaric acid (most common)
Citric acid (not permitted in EU for acidification)
Malic acid (less used as it could be turned into lactic acid by MLC)
Lactic acid (may be used to make adjustments after MLC; tastes less harsh than other acids)

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52
Q

Describe the process for deacidification and why it would be used

A

Deacidification is carried out by adding calcium carbonate (chalk) or potassium carbonate. This lowers acidity by formation and precipitation of tartrates.
High-tech option is by ion exchange - expensive.
EU - only deacidify within legal limits
In cool climates where grapes may be picked before fully ripe, it may be necessary to deacidify wine.
Any calculation of desired final level of acidity will need to take into account any lowering acidity brought about by MLC.

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53
Q

Describe the enrichment process for wine

A

Chaptalization is the common practice of adding dry sugar in the form of beet or cane sugar. This is a common practice in cooler climates to enrich must before or during fermentation to increase alcohol in final wine.
EU - only permitted in cooler zones.
Sugar added when fermentation underway because yeast are active and can cope better with additional sugar.

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54
Q

Describe how you can reduce alcohol in wine

A

In warm/hot regions where sugar can accumulate in grapes quickly, it may be desirable to lower potential alcohol of wine slightly by adding water to grape must. Only legal in some countries (California).
Adding water dilutes grapes’ aromas, flavours and acids.

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55
Q

Describe the process of adding tannins to wine

A

`Powered tannins may be added to help clarify musts. With red wines, it helps stabilize colour of musts and improve mouthfeel. Tannins may be added before fermentation or to wine before maturation.

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56
Q

Describe what ambient yeast is

A

Ambient yeast is present in the vineyard and winery. It includes a range of species (Kloeckera, Candida). Most die out as alcohol rises past 5%. Then Saccharomyces cerevisiae becomes dominant strain, even in wild fermentations.

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57
Q

Describe the advantages and disadvantages of ambient yeast

A

Advantages - adds complexity as a number of yeasts produce different aroma compounds
Costs nothing to use
Yeast population unique to place/region
May be used as part of marketing of wine
Disadvantages - Fermentation starts slowly - can build up unwanted volatile acidity and growth of spoilage organisms and bacteria - leads to off-flavours
Fermentation to dryness takes longer - not desirable in high volume wineries
Increased risk of stuck fermentation leaves wine vulnerable to spoilage organisms
Consistent product not guaranteed

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58
Q

Describe what cultured yeast is

A

Cultured yeast are strains selected in a lab and grown in volumes suitable for sale. Often single strains of saccharomyces cerevisiae.
To use cultured yeast, must is cooled down to prevent fermentation by ambient yeast and cultured yeast is added, which quickly takes over.
Another option is to add SO2 to must to suppress ambient yeasts.
Starter batch is made up of fermenting grape must which has been activated with cultured yeast, is then added to the tank of must to be fermented.

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59
Q

Describe the advantages of using cultured yeast

A

Produces reliable, fast fermentation to dryness
Produces low levels of volatile acidity - less danger from spoilage organisms and bacteria
Helps produce consistent product from vintage to vintage
Large selection of cultured yeast strains - winemakers choice can affect style of wine created
Can choose a neutral yeast for sparkling wine base
Or strain of yeast to boost aromatic character
Saccharomyces bayanus sometimes used for must with high potential alcohol or for re-fermenting sparkling wine.

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60
Q

Describe the disadvantages of using cultured yeast

A

Some believe cultured yeast leads to a certain similarity of fruit expression
Adds cost by using a commercial product

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61
Q

What is the temperature range for cool temp fermentations and what effect does it have on the final wine

A

Cool fermentation - 12-16 C
Fresher, fruitier white wines and rose
Cool temps promote the production and retention of esters that give fruity aromas and flavours

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62
Q

What is the temperature range for mid-range temp fermentations and what effect does it have on the final wine

A

Mid-range fermentation - 17-25 C
Easy-drinking fruity red wines to retain fruit aromas and for low tannin extraction
Middle of this temp range for less fruity white wines, top of this range for barrel-fermented white wines

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63
Q

What is the temperature range for warm temp fermentations and what effect does it have on the final wine

A

Warm fermentation - 26-32 C
Used for red wines with pronounced flavour concentration and high tannins
Maximum extraction of colour and tannins, but can result in some loss of fruity flavours

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64
Q

Describe the use of stainless steel fermentation vessels

A

Stainless steel vessels is the modern standard. Easy to clean, comes in range of sizes and allows temp control.
Neutral vessels and good at protecting wine from oxygen - does not add any flavours
Most common vessel in modern, high-volume wineries due to price, hygiene, and high level of mechanization
Can require substantial initial investment

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65
Q

Describe the use of concrete fermentation vessels

A

Concrete vessels were inexpensive option in last century, with vats being built in situ on a large scale.
Now coming back into fashion because of high thermal inertia - maintain temp more efficiently than stainless steel
Smaller, egg-shaped vessels in concrete, are very expensive. Said to setup convection currents that mix fermenting must and mix lees during maturation.

66
Q

Describe the use of wood fermentation vessels

A

Wood retains heat and some winemakers value the small amount of oxygen that fermenting red wine in oak provides.
Great care has to be taken with hygiene as pores in wood can harbour bacterial and spoilage organisms.
Can be reused many times and are inexpensive in the long term. Require capital investment when new large oak casks are bought.

67
Q

Describe alternative options for fermentation vessels

A

Plastic vessels are light, versatile and useful for small-batch fermentations. Is permeable to oxygen and can be difficult to control temp in plastic vessels.
Terracotta used historically and in use in small-scale production today. Pots made from terracotta are known by various names - amphora, qvevri (Georgia) and tinaja (Spain)

68
Q

Describe what malolactic conversion is

A

MLC is a result of lactic acid bacteria converting malic acid into lactic acid and carbon dioxide; also produces heat. Usually happens after alcoholic fermentation and occassionally during it.
Certain conditions encourage MLC - 18-22C, moderate pH (3.3-3.5) and low total SO2
Can be started by adding (inoculating) cultured lactic acid bacteria and making sure optimum conditions are available.

69
Q

Describe the conditions that inhibit MLC from happening

A

Conditions that prevent MLC - temp below 15C, low pH and moderate levels of SO2.
To ensure MLC does not happen, can add the enzyme Isozyme, which kills lactic acid bacteria.
Or move any batch of wine going through MLC to another part of the winery to avoid spread of lactic acid bacteria.
Lactic acid bacteria can be filtered out to avoid MLC

70
Q

Describe the effects/outcomes of malolactic conversion

A

Acidity/pH - reduction in acidity and rise in pH
Colour - some colour loss in red wines - not a problem except in very pale red wines
Greater microbial stability - If wine goes through MLC during or after fermentation, this prevents MLC from spontaneously happening later when undesirable
If pH in wine is high, raising pH slightly makes wine more vulnerable to spoilage organisms
Modification of flavour - slight loss of fruit character with addition of buttery notes (notably in whites)
Process will also increase volatile acidity

71
Q

List what post-fermentation adjustments can be made on wine

A

Acidity, pH and tannins can be adjusted
Removal of alcohol
Colour

72
Q

Describe how alcohol is removed from wine as part of post-fermentation adjustments

A

May be desirable to remove alcohol to produce a reduced alcohol wine or adjust level of alcohol marginally.
Simplest solution for marginal adjustment is to add water to must, but it reduces the intensity of flavour.

73
Q

Describe how colour is adjusted as part of post-fermentation adjustments

A

Winemakers may wish to reduce unwanted colour tints, for example by fining wine.
When making high-volumed red wines, enhance colour intensity by adding very small amounts of the grape-derived colouring agent, MegaPurple - not permitted in some regions

74
Q

Describe the role of oxygen in maturation of wine

A

Oxidation plays role in way aroma and phenolic compounds evolve in wine. It leads to gradual reduction in primary aromas and development of tertiary aromas (dried fruit, nuts)
Can influence the colour of wine. White wines become darker, gradually becoming gold and brown.
Exposing young red wines to oxygen can result in greater colour stability and intensity. Important for light-coloured red wines like Pinot Noir.
Speed of oxidation influenced by amount of oxygen exposure, compounds in the wine and temp

75
Q

How long do red and white wines typically undergo pre-bottling maturation

A

Red wine - 12-24 months of pre-bottling maturation is common
White wine - 6-12 months of pre-bottling maturation is common

76
Q

Describe the role of wooden vessels and oxygen in the maturation of wine

A

By storing wine in small wooden vessels, it is a method of gaining a slow, gradual exposure to oxygen. Some oxygen released from pores in first few months. Very small amount of oxygen continues to pass through gaps between staves and bung hole.
Wine is most exposed to oxygen in this process is during any transfer of wine (racking, lees stirring, topping up) in which bung is removed

77
Q

Describe the process called micro-oxygenation

A

Micro-oxygenation involves bubbling oxygen through wine. The dose is mg/L per month. Usually done in SS tanks for a number of months post alcoholic fermentation. Cheaper alternative to maturing wine in barrels.
Increases colour stability and intensity, softens tannins, improves texture and reduces presence of unripe, herbaceous flavours.
Can be used with oak alternatives to help integrate oak influence.

78
Q

List the features of wooden vessels that effect the level and type of compounds extracted from wood vessels

A

Age of the vessel
Size of the vessel
Type of wood
Production of the vessel
Length of time in wood

79
Q

Describe the characteristics of European oak

A

European oak is subtler than American oak.
European oak imparts more tannin.
Oak trees in Europe grow slower, so they have tighter grain. Allows for gradual extraction of oak aroma compounds and tannins.
European oak must be split to create staves - less barrels can be made from European oak. Making them more expensive.

80
Q

Describe the characteristics of American oak

A

American oak has higher levels of lactones - gives aromas of coconut. Imparts greater intensity of aromas / flavours.
American oak can be sawn - get more vessels out of American oak, making them cheaper.
American oak grows quicker than European oak - also contributes to making them cheaper.

81
Q

Describe the role of lees in still wine maturation

A

After fermentation, yeast cells die and break down in a process called autolysis. This releases compounds that contribute flavours, body and texture to wine.
Some of these compounds bind with phenolic compounds in grapes, reducing colour and softening tannins. Compounds also bind with extractable compounds of wood and can reduce astringency and modify flavours from wood.
White wines - yogurt, dough, biscuit, toasted bread
Helps protect wine form oxygen, helping maintain a slow, controlled oxidation during maturation and lowering need to use SO2 during this time.

82
Q

Describe the racking process

A

Racking is the process of transferring wine from one vessel to another with aim of removing sediment from wine. Can be an oxidative process.
Some red winemakers will increase oxygen exposure by deliberately splashing the wine.
Can protect wine with inert gas.
May be carried out once or several times during maturation process.

83
Q

List the key reasons for blending wine

A

Balance
Consistency
Style
Complexity
Minimize faults
Volume
Price

84
Q

Describe why balance is a key reason for blending wine

A

Blending may help increase or moderate levels of characteristics of wine to produce better balanced wine.
Batch of wine from warmer vineyard or picked late may be blended with batch from a cooler vineyard or has been picked early to fine tune acidity levels.
Use of different varieties is common way to enhance balance of wine - Merlot provides body and ripe, plummy fruit to blend with Cabernet Sauvignon, which when not fully ripe, can be too astringently tannic on its own.

85
Q

Describe why consistency is a key reason for blending wine

A

Variation among bottles of a single product in a single vintage is usually seen as a fault.
Blending can ensure a certain volume of a consistent product. Some wine styles need consistency across different vintages.
Includes most Sherry and non-vintage sparkling wine.
Many inexpensive wines where consumers my not accept significant vintage variation.

86
Q

Describe why style is a key reason for blending wine

A

Blending is often fundamental in reaching a desired style. Even where vintage variation is accepted, winemakers often make wines to a certain house style or want to create wines of certain quality levels within their range.
Some roses are made by blending red and white wines - allows precise control over colour and flavour profile.

87
Q

Describe why complexity is a key reason for blending wine

A

Blending of 2 or more parcels of wine may lead to greater range of flavours. Can enhance complexity and quality of final wine.

88
Q

Describe why minimizing faults is a key reason for blending wine

A

Blending may be carried out to help reduce the presence of faults in wine.
If wine in one barrel shows significant volatile acidity, that wine may be sterile-filtered to remove acetic acid bacteria and then blended into a larger volume of un-faulty wine to lower the concentration and sensory perception of acetic acid.

89
Q

Describe why volume is a key reason for blending wine

A

In areas with small vineyards, winemakers likely need to blend wines from different vineyards to produce viable volumes of wine.
In poor vintages or where producers have minimal vineyard holdings, grapes, must or wine may need to be bought to satisfy the needs of consumers.

90
Q

Describe how the blending process works

A

Blending usually starts with blending trials using measuring cylinders and small volumes of wines to distinguish the proportion of each wine in flavoured blend before conducting on a larger scale. This process requires high level of skill and experience.
Blending can be challenging, especially when blending young wines that are destined for long ageing - winemaker needs to estimate how the blend will develop.

91
Q

What are the reasons why post-fermentation clarification is done

A

Reduce risk of faults developing
Consistency
Consumer satisfaction and expectations

92
Q

Describe the post-fermentation clarification process called sedimentation

A

Sedimentation is when wine is stored in cool cellar conditions. The clarification process will begin naturally, with suspended matter precipitating over time. Wine is allowed to stand and particles with higher density than wine will form a sediment at the bottom of the container.
Wine can be racked off, leaving the sediment behind.
If wine is to be barrel aged, then sedimentation will happen as part of the barrel ageing process.

93
Q

Describe why the clarification process called sedimentation is only used for premium wines

A

Winemakers believe clarification by sedimentation avoids potential loss of texture and flavour that may occur if wine is fined or filtered.
Sedimentation takes time, which has a cost as wine cannot be sold until it is clarified. This is why sedimentation is usually only suitable for premium or super-premium wines.

94
Q

Describe the post-fermentation clarification process called centrifugation

A

Centrifugation is a rapid process that spins the wine at high speed to clarify it. It can replace depth filtration and allow early bottling.
It is very effective with wines with a lot of matter in suspension.
Usually only practiced in high-volume wineries to spread the considerable cost of buying the machine.

95
Q

Describe the post-fermentation process called fining

A

Fining is a procedure in which a fining agent is added to speed up the process of the precipitation of suspended material in wine.
Fining agents can be of a protein or mineral origin.
Removes small proportion of unstable colloids (microscopic particles too small to be removed by filtering)
Helps clarify wine and stabilize it against formation of hazes later in the bottle.
Fining agents have opposite charge from the wine colloid to be removed. Fining agent and colloid attract each other and form a solid large enough to be removed by racking or filtration

96
Q

Describe why the minimum effective amount of fining agents should be used when fining wine

A

Many fining agents can remove desirable compounds from wine or make wine unstable when too much is added (over-fining).
Winemakers conduct lab trials before using fining agents to ensure that minimum effective amount is used - they compare fined sample with original wine before processing.

97
Q

Describe the fining agent that removes unstable proteins

A

Bentonite is a form of clay that absorbs unstable proteins and unstable colloidal colouring matter. It has minimal effect on flavour and texture of wine. Does lead to some colour loss in red wines and produces large amounts of sediment. Wine is lost when it is racked off.
Can be used to fine must as well as wine.
Must and wine contain grape-derived proteins.
Not necessary to remove these in red wine - they bind with tannins, precipitate naturally and removed when wine is racked.
Proteins in white/rose wines can agglomerate into a visible haze if warmed up (in transit) and is seen as a fault.

98
Q

List the fining agents that are used to remove phenolics that contribute undesirable colour and bitterness

A

Egg white
Gelatine
Casein
Isinglass
Vegetable protein production
PVPP - Polyvinylpolypyrrolidone

99
Q

Describe the use of egg white as a fining agent

A

Egg white is a fining agent that can remove phenolics that contribute to undesirable colour and bitterness.
Due to its protein content, egg white is often used in fresh or powdered form.
Used for high-quality red wines because it can remove harsh tannins and clarify wine. It is gentle.
It is an allergen and must be declared on label.
Not suitable for vegan wines.

100
Q

Describe the use of gelatine as a fining agent

A

Gelatine is a protein collagen extracted from pork that aids clarification, removes bitterness and astringency in red wine and browning in white wine pressings.
Add in smallest effective amount - easy to over-fine. Strips flavour and colour, creating risk of protein haze forming later.
Not suitable for vegetarian or vegan wines as it is derived from animals.
Can be used to fine must as well as wine.

101
Q

Describe the use of casein as a fining agent

A

Casein is a milk-derived protein that removes browning from white wines and clarifies wines to some extent.
Is an allergen - Must be declared on label
Not suitable for vegans is it is derived from milk.
Can be used to fine must as well as wine

102
Q

Describe the use of isinglass as a fining agent

A

Isinglass is a protein collagen that effectively clarifies white wines, giving them a bright appearance.
Smallest effective amount must be added to avoid potential for formation of protein haze later and creation of fishy smell.
Not suitable for vegetarian or vegan wines as it is derived from fish bladders.

103
Q

Describe the use of Vegetable protein production and PVPP as fining agents

A

Vegetable protein production is derived from potato or legumes and is suitable for vegetarian and vegan wines.
PVPP - Polyvinylpolypyrrolidone - is insoluble plastic in powder form that removes browning and astringency from oxidized white wines. It is gentler fining agent than charcoal. Rarely used on red wines, but can reduce astringency and brighten the colour.

104
Q

Describe the fining agent used to remove colour and off-odours

A

Charcoal removes brown colours and some off-odours. Care needs to be taken as it over-fines easily removing desirable aromas and flavours.
One option is to treat only 1 batch of affected wine and then blend it with rest of wine to reduce the effect.

105
Q

List the two main types of filtration

A

Depth and surface filtration

106
Q

List the types of depth filtration

A

Diatomaceous earth (DE)
Sheet Filters

107
Q

List the types of surface filtration

A

Membrane filters
Cross-flow filters

108
Q

Describe what depth filtration is

A

Depth filtration is a method that traps particles in depth of material that forms the filter. It can cope with fluid with many particles in it - wine just pressed or has lees.
Small particles are trapped in many irregular channels through the filter. It does not block easily.
Not absolutely reliable - if too much pressure applied or if filter used for too long, some particles will make their way through the filter. It is not an absolute filter.

109
Q

Describe how diatomaceous earth depth filters work

A

Most common form of depth filtration uses DE. Once it is processed, it is pure silica and inert.
DE is wetted and used as a filter medium. Wine sucked by vacuum from outside a rotary drum, through the DE, to the inside of the drum. Rotary vacuum filters use this method to filter very thick and cloudy wine.
Is an oxidative process as drum is exposed to air.
Enclosed DE filters do same job - can be flushed with inert gas (nitrogen) to avoid oxidation.
DE comes in range of particle sizes and can remove large or very small yeast particles.

110
Q

Describe how sheet filter depth filters work

A

Sheet filters are also known as ‘plate and frame’ or ‘pad’ filters. Wine passes through a sheet of filtering material. The more sheets there are in the filter, the quicker the wine can be filtered.
Very fine graded sheets can be used to remove remaining yeasts at bottling.
Requires initial investment (frame must be robust to withstand pressure involved). Cost of filters is low.
Trained personnel must operate them to work properly.

111
Q

Describe how membrane filter, which are surface filters work

A

Membrane filters catch particles that will not go through the pore size of the filter. Slower than depth filter as pores are smaller - often less than 1 micron.
Wine must be pre-filtered first by depth filtration or membrane filters can get blocked.
Usually used as a final precaution before wine is bottled to ensure wine is clear and microbiologically stable.
Sometimes called sterile filtering.
Initial investment is small, but cartridges are expensive and ongoing cost.
Common form of filtration during bottling/packaging process.

112
Q

Describe how cross-flow filters, which are surface filters work

A

Cross-flow filters allow wine to pass through the filter while uniquely cleaning the surface of the filter as it works. Solid particles cannot pass through the filter.
Can filter wine with high load of particles or lees very quickly.
No replacement sheets, cartridges or earth to buy or dispose of. Machines are expensive, making them more suitable for large and/or well funded wineries.

113
Q

Describe what the stabilization process is

A

Stabilization refers to several winemaking interventions, if not carried out, could lead to undesired effects in finished wine.
Includes tackling unwanted hazes, deposits in bottle and rapid changes in wine (browning).
Tartrate stability, fining and filtering all contribute to clarification and stabilization
Two types of stabilization are protein and tartrate stability.
Protein stability - fining with bentonite is the key procedure to ensure protein stability.

114
Q

Describe what tartrate stability is

A

Tartrates are mostly potassium bitartrate, and less frequently, calcium tartrate. They are harmless deposits of crystals that can form in finished wine.

115
Q

List the options winemakers have to prevent tartrates from forming

A

Cold stabilization
Contact process
Electrodialysis
Ion Exchange
Carboxymethylcellulose (CMC)
Metatartaric acid

116
Q

Describe the cold stabilization process which is used to prevent tartrates

A

Wine is held at -4C for 8 days so crystals form before bottling and then they can be filtered out.
Requires equipment and cost of energy to refrigerate the wine.
Colloids must be removed by fining before this process as they could prevent crystals from forming.
This process only removes more common potassium bitartrate, not calcium tartrate.

117
Q

Describe the contact process which is used to prevent tartrates

A

Contact process is a quicker, continuous process that is a more reliable and cheaper form of cold stabilization.
Potassium bitartrate is added to wine and speeds up the start of the crystallization process.
Wine cooled to 0C and after 1-2 hours the crystals are filtered out.

118
Q

Describe the electrodialysis process which is used to prevent tartrates

A

Electrodialysis is a processes that uses a charged membrane to remove selected ions. It removes potassium and calcium ions, and, to a smaller extent, tartrate ions.
High initial investment, then total costs are lower than cold stabilization.
Process uses less energy and is faster.
Is allowed in EU and other territories for tartrate stabilization

119
Q

Describe the ion exchange process which is used to prevent tartrates

A

Ion exchange is a process that does not remove tartrates, but it replaces potassium and calcium ions with hydrogen or sodium ions, which will not drop out of the solution.
Process not allowed in some territories as it replaces potassium with sodium, which is not conducive to health. Resulting levels in wine are well below legal limit.

120
Q

Describe the carboxymethylcellulose (CMC) process which is used to prevent tartrates.

A

Cellulose is extracted from wood and prevents tartrates from developing to a visible size.
Widely used on inexpensive white wines. Not suitable for red wines as it reacts with tannins, rendering it ineffective, and causing hazes.
Much cheaper than chilling.
Keeps wine stable for a few years.

121
Q

Describe the metatartaric acid process which is used to prevent tartrates

A

Metatartaric acid is added to prevent growth of potassium bitartrate and calcium tartrate crystals, reducing the need for cold stabilization.
Compound is unstable, and positive effect lost over time, especially when wine is stored at high temps (25-30C)

122
Q

Describe how microbiological stability is obtained so wines with residual sugar don’t start to re-ferment in the bottle

A

Wines with RS can start to re-ferment in the bottle.
Can remove yeast through sterile filtration.
Alternative is to add sorbic acid and SO2, which inhibits yeast from growing. Some people can smell sorbic acid.
Wines with lactic acid bacteria where MLC has not been carried out are liable to start MLC in bottle.
Solution is to ensure MLC has completed or filter the wine to remove the bacteria.
If Brett is a problem, wine can be treated by filtering or DMDC (dimethyl dicarbonate - Velcorin) before bottling, which inactivates Brett.

123
Q

List what finishing options are available to winemakers.

A

Before final finishing options carried out, winemaker will do a full chemical analysis. Will make adjustments in light of the analysis.
Adjusting level of sulfur dioxide
Reducing dissolved oxygen
Adding carbon dioxide

124
Q

Discuss adjusting sulfur dioxide levels as a finishing option

A

Winemakers check SO2 levels and adjust before bottling. Must ensure levels are within legal limits.
Both total SO2 and free SO2 are measured. Free SO2 contains molecular SO2, which is the effective part.
Many factors affect SO2 levels - winemaking approach, wine style, pH and intended drinking period.

125
Q

What are the free SO2 levels in white, red and sweet wines

A

White wine - 25-45 mg/L (lower than for red wines due to lower pH)
Red wine - 30-55 mg/L
Sweet wine - 30-60 mg/L

126
Q

Discuss reducing dissolved oxygen as a finishing option

A

Oxygen dissolved in wine can accelerate the speed of ageing of wine and reduces its shelf life.
If levels of oxygen are too high, it can be removed by flushing the wine with an inert gas to remove it. This process is called sparging.

127
Q

Describe what the process called sparging is

A

Sparging is used when levels of oxygen in wine are found to be too high. They can be removed by flushing the wine with an inert gas to remove it.

128
Q

Describe the process of adding carbon dioxide as a finishing option

A

A small amount of CO2 may remain in wine after finishing and packaging.
In inexpensive youthful white and rose wines, some winemakers add a tiny bit of spritz from CO2 for added freshness.
If desired, CO2 is added just before bottling.

129
Q

List the faults that can happen in wine

A

Cloudiness and hazes
Tartrates
Re-fermentation in bottle
Cork taint
Oxidation
Volatile acidity
Reduction
Light strike
Brettanomyces

130
Q

Explain why wines develop cloudiness and hazes and how can you correct the fault

A

Wines can develop cloudiness or hazes due to growth of yeast and bacteria along with a failure to filter wine adequately. Cloudiness can also be due to poor filtering of wine. Can also be due to a protein haze where fining is not effective, where wrong type of fining agent was used or wine was over-fined.
Remedy with better hygiene in winery, pre-bottling chemical analysis and filtering wine to remove yeast and bacteria before bottling. Can also remedy by fining correctly and conducting analysis after fining.

131
Q

Explain why re-fermentation in the bottle may occur and how you can prevent the fault

A

Some consumers may regard spritz as a fault. If accompanied by cloudiness, it would indicate unwanted re-fermentation in bottle. This is due to the failure to stabilize and clarify/filter wine adequately.
Some wine styles purposely include low level of spritz - Muscadet sur lie, Vinho Verde)

132
Q

Explain why volatile acidity may occur and how you can prevent the fault

A

All wines have volatile acidity, but excessive amounts give pungent smell of nail varnish and/or vinegar.
It is due to the activity of acetic acid bacteria, inadequate SO2 levels and excess exposure to oxygen.
Threat can be reduced by sorting fruit to exclude damaged grapes, good hygiene in winery, keeping vessels topped up, careful racking, avoid excessive exposure to oxygen and maintaining adequate SO2 levels.

133
Q

Explain why reduction may occur and how you can prevent the fault

A

Reduction is associated with sulfur-like odours that range from onion to rotten eggs. Smells are caused by high levels of volatile, reductive sulfur compounds. They can be produced by yeast under stress (low nitrogen levels). Can also be due to the near exclusion of oxygen during ageing in closed vessels, especially when lees ageing.
Can be avoided by making sure yeast is not stressed, ensure sufficient nutrients and oxygen, and must is at an adequate temp.
SO2 may need to be lowered, especially if closure used allows very little oxygen ingress.

134
Q

Explain why light strike occurs and how you can prevent the fault

A

Light strike is caused by UV radiation and certain wavelengths of visible light reacting with some compounds in wine to form volatile sulfur compounds - gives odours of dirty drains.
Wines left in direct sunlight are most at risk, but also wines placed near fluorescent lighting are at risk.
Choice of packaging can be a factor - wine packaged in clear glass are most likely affected. Dark glass (green, particularly brown) provide more protection.

135
Q

Explain why Brettanomyces occurs and how you can prevent the fault.

A

Brett yeast produce off-aromas (animal, spicy, farmyard smells). Once winery infected it is difficult to eradicate, especially as wood can host organism and is difficult to clean.
Key ways to avoid are - excellent hygiene, maintaining effective SO2 levels, keep pH levels low, keep time period between end of fermentation and MLC as short as possible, so SO2 can be added as soon as possible.
If wine affected by Brett, can be treated by filtration or DMDC (dimethyl dicarbonate - Velcorin) before bottling. This inactivates Brett.

136
Q

Describe what oxygen transmission rate total package oxygen is in regards to oxygen management when packaging

A

Oxygen transmission rate (OTR) - the rate of transmission of oxygen through the closure
Total package oxygen is a combination of:
- Amount of dissolved oxygen in wine
- Oxygen in head space (below cork) - usually greatest contributor
- Amount of oxygen in cork or other closure
- OTR of cork/closure

137
Q

List the options for packaging wine

A

Glass bottles (preferred)
Plastic
Bag-in-box
Brick
Pouch
Can

138
Q

Describe the advantages and disadvantages of glass bottles

A

Advantages - inert and conveys no taint to wine
- Bottles delivered to winery in sterile condition - shrink-wrapped when still hot
- Inexpensive to manufacture; range of colours
- 100% recyclable - some colours easier to recycle than others
- Best packaging option for ageing wine
Disadvantages - High carbon footprint to manufacture
- Heavy to transport, contributing to carbon footprint
- Fragile and rigid
Wine can by spoiled by light strike

139
Q

Describe plastic used for packaging wines

A

PET (polyethylene terephthalate) is a form of plastic that is light, tough, inexpensive and recyclable.
Must be lined with a barrier to reduce ingress of oxygen and give reasonable shelf life
Range of sizes - standard bottle size & single serve
Well suited for wines with limited shelf life and for quick consumption
Special filling equipment required as PET bottles are inflated at filling

140
Q

Describe bag-in-box used for packaging wines

A

Cardboard box that houses a flexible bag inside made of aluminum foil (barrier to oxygen)
Bag can be made from plastic that gives some protection from oxygen and is resistant to cracking, unlike aluminum
Wine must have slightly higher SO2 to counter oxidation, low dissolved oxygen level, no head space and low carbon dioxide (avoid bag bulging)
Must use high-quality tap as this is where must oxygen ingress occurs. Shelf life is 6-9 months

141
Q

Describe the advantages of bag-in-box packaging for wines

A
  • Flexible pour size (one or more classes)
  • Good protection from oxygen after wine has been poured (bag collapses inside box)
  • Range of sizes from 1.5 - 2.0 litres. Suitable for home and commercial
  • Easy to store (less fragile) and easily stacked
  • Low environmental impact (light to transport, can be recycled)
142
Q

Describe the brick and pouch options for wine packaging

A

Brick - tetra pack - made of paper card with plastic layers and an aluminum foil layer that excludes oxygen and light. Package filled entirely with wine, excluding oxygen. Filling equipment is a big investment.
Pouch - similar to bag-in-boxes. Available in larger 1.5 litre and single serve sizes

143
Q

Describe how cans are used for wine packaging and the advantages

A

Aluminum can lined with plastic to avoid being attached by acidity of wine. Filling equipment is a big investment; producers usually outsource filling of cans.
Advantages - light weight, robust, easy to open; impermeable to oxygen and recyclable

144
Q

List the options for wine closures

A

Natural cork
Technical cork
Synthetic closures
Screwcap
Glass stoppers

145
Q

Describe the use of natural cork as a wine closure

A

Natural cork is light, flexible, inert and comes from a renewable, natural resource. Comes in a range of length and quality. Shorter, lower-grade corks are cheaper - for inexpensive wines intended for short consumption. Better quality, longer corks used for higher priced wines that may age in bottle.

146
Q

Describe 2 issues with natural cork

A
  • Corks can taint wine through TCA and other compounds. Unpleasant smell of mould and wet cardboard suppresses fruit character.
  • While cork is generally a good oxygen barrier, they have variable rates of oxygen ingress. Same wine bottled with cork age at different rates due to variable rates of oxygen ingress of individual corks.
147
Q

Describe approaches the cork industry is taking to reduce or eliminate cork taint

A
  • Cleaning corks with steam extraction (Amorim)
  • Creating closures from recomposed cork particles that have been cleaned and reconstituted with plastic (Diam - technical cork)
  • More rigorous quality control - high-tech solutions like gas chromatography to check for presence of TCA.
  • Introduce inexpensive polymer barrier between cork and wine - impermeable membrane between cork and wine that gives wrinkled appearance on end of cork and excludes any aromas reaching wine from cork
148
Q

Describe what technical corks are

A

Technical corks are made from cork that has been subjected to a manufacturing process and designed to address issues of cost and avoid cork taint.
Cheapest option is agglomerated cork - cork granules glued together - only suitable for inexpensive wines intended to be drunk soon after purchase.
One-plus-one cork - largest, central section is inexpensive agglomerate, but finished with a disk of natural cork at both ends - Diam corks
Available with different oxygen ingress rates so winemaker can choose a closure for wines to be drunk in short term or for ageing.

149
Q

Describe what synthetic corks are

A

Synthetic corks are plastic corks, synthetic closures made of food-grade plastic with silicone coating. Cheapest are moulded closures.
Rigidity makes them more difficult to re-insert in bottle. Extruded closures addressed this issue and are more elastic - made by external firm layer of plastic covering a plastic foam.
Offer limited protection from oxygen ingress and only suitable for wines intended for consumption within months of bottling.
Extruded closures new have range of oxygen-ingress rates - Nomacorc claims top line is suitable for extended ageing in bottle.
Plastic closures cause flavour scalping - loss of some flavour intensity because plastic absorbs some flavour molecules

150
Q

Describe what screw cap closures are

A

Screwcap are aluminum closures rolled onto outside of bottleneck specially designed for this purpose. Requires different equipment.
Seal with tin (impermeable to oxygen) or Saran (low permeability to oxygen)
Does not permit oxygen ingress - can lead to reductive unpleasant odours like onion on first opening. To avoid this issue, final wines should have slightly lower SO2 levels.

151
Q

Describe what glass stoppers are

A

Vinolok brand name - glass stoppers made from glass, but seal is formed by plastic ring.
Wine can be stored for similar lengths of time as those closed by natural cork, but special bottles are needed.
They look attractive and are as expensive as top-quality cork. Only suitable for premium and super-premium wines

152
Q

Describe how traditional bottling works

A

When wines finished fermentation, the acid, alcohol and lack of nutrients creates a hostile environment for microbial growth.
Where wines matured over extended time period in a cool cellar, they become clear by natural processes.
Producers siphon wine directly to bottle and seal with a cork.

153
Q

Describe how modern bottling techniques work

A

Before being filled with wine, bottles are rinsed with sterile water and steam cleaned - heated to 82C for 20 mins. Called aseptic bottling - involves elimination of harmful yeast/bacteria
Sterile filtration - removes micro-organisms. No heat applied to wine and bottling carried out at ambient temp.
Heat treatment - kills micro-organisms. Flash pasteurization in which wine is heated to high temp (80-90 C) for a few seconds and then cooled rapidly. Then wine is bottled.

154
Q

List how quality assurance and risk assessment benefit the producer / consumer

A

Protection
Reputation
Reduced costs
Consistency
Traceability

155
Q

Describe the 3 procedures for hygiene in the winery

A
  • Cleaning - removal of surface dirt
  • Sanitation - reduction of unwanted organisms to low levels with water and detergent or other sanitizing agent and/or steam. Every litre of wine produced, 10 litres of water used for hygiene purposes.
    Sterilization - elimination of unwanted organisms. From high risk areas like filler heads of bottling lines. Can be sterilized with high strength alcohol or steam.
156
Q

Describe what HACCP is

A

HACCP is Hazard Analysis of Critical Control Points. It is an approach to quality assurance regarding significant threats to safety of consumers and to reputation of a wine company.
For each hazard, the HACCP document states how serious it is, how it can be prevented and how it can be protected.
Example: in bottling line there is a possible harzard of glass breaking and ending up in a bottle of wine (threat to consumer). In a highly mechanized winery, preventive action would be to have a system in place to detect a broken bottle and push out next 2 bottles automatically to remove bottles that could have been affected by shards of glass.

157
Q

Describe what ISO standards are

A

Wine companies seeking external validation of their quality standards can be audited against ISO standards. Purpose is to give assurance to all parties down the supply chain: wholesaler, retailer and end consumer.

158
Q

Describe why a formal system for traceability is necessary for a wine company

A

A formal system for traceability is necessary if wine company is going to respond to and investigate complaints about its wine. Complains can come from supply chain and final consumer.
It can improve its practice so similar problems don’t occur in the future.

159
Q

Describe the 2 type of containers used for bulk shipping of wine

A

Flexitank - single-use, recyclable polyethylene bag that fits into a standard container. It is coated with a barrier to prevent taint from external source and reduce oxygen ingress.
ISO tank - a SS vessel built to ISO standards that can be reused many times and may have additional insulation. Insulated tanks with temp control (reefers) are available, but additional cost

160
Q

Describe what the advantages and disadvantages of shipping wine in the bottle are

A

Advantages - the wine, bottling, labelling and any external packaging is controlled by producer.
Disadvantages - smaller amount of wine shipped in 1 container - higher cost.
Financial and environmental cost of shipping weight of glass as well as wine
Potential damage to wine due to fluctuating temps in transit; potential spoilage of labels and packaging
Shorter shelf life of inexpensive wine because it is bottled earlier than if it were bottled in or close to final market

161
Q

Describe the advantages of shipping wine in bulk

A
  • More environmentally friendly - 1 container holds 32,000 bottles rather than 12-13,000 filled bottles
  • Reducing carbon footprint
  • Greater thermal inertia of a whole container filled with wine - less temp fluctuations. Reduces risk of loss of fruit and oxidation
  • Strict quality control - key parameters of wine (RS, SO2) can be measured at point of filling and emptying
    Wine can be adjusted at point of bottling close to consumer
    Shelf life can be extended as this is calculated from time of bottling - relevant for bag-in-box with its short self life
162
Q

Describe the disadvantages of shipping in bulk

A
  • Loss of direct relationship with producer
  • Transfer of business and employment opportunities from producer countries to countries close to final market
  • Shipping in bulk only commercially viable for larger brands - those that will sell 3 or more containers per year

WSET Level 4 D1 Wine Production (6 decks)

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