WSET Diploma D1 General Wine Making Options CH13

Question 1

What are 2 most fundamental Gases in Winemaking and Maturation

Answer 1

Oxygen & Sulfur Dioxide

Question 2

How can oxygen on the must or wine be limited

Answer 2

• Avoid ullage in vessels - topping (wood vessels gradual loss through evaporation
• Use of Inert Gases to flush out oxygen (nitrogen, carbon dioxide, argon)
• Addition of SO2 (anti oxidative effects)
• Use of impermeable containers (Stainless Steel, Glass & Screwcap, Thick concrete)
• Cool consistent temps (in cellar, while picking, slows oxidation)

Question 3

How is or can oxygen be positive for wine/must

Answer 3

• Required to start fermentation
• Needed for health yeasts
• Oxidation stability (before fermentation, longer aging)
• Essential for anthocyanin and tannin reactions, COlor stability
• Quality/style of wine
• Develop aromas and flavor characteristics

Question 4

Ways to increase oxygen exposure

Answer 4

• Cap management techniques (red wine)
• Small wooden barrels with small amount of wine
• Increas number of rackings or lees stirring
• Allow ullage in conatiners without inert gasses
• Pump oxygen through must

Question 5

What is SO2 primarily used for, and what are its 2 main properties

What forms can it come in

Answer 5

Preservative in wine

• Anti Oxidant - reacts slowly with oxygen, reduces oxidation effects
• Anti Microbial - slows development of microbes (yeast, bacteria)

Gas, Liquid, Solid

Question 6

What is Max SO2 you can use in EU

Answer 6

210 mg/L - Red Wines

160 mg/L - White Wines

Question 7

How uch SO2 naturally occurs, at what point must contain sulfites be put on the lable

Answer 7

up to 10 mg/L, anything more must be put on the lable

Question 8

Bound SO2 vs free SO2

Answer 8

Bound - when SO2 added to must or wine, dissolves and some reacts with compounds in liquid, ineffective against oxidation and microbes

• Free, portion non bound, relatively inactive. Some is Molecular - effective agains oxidation and microbes

Question 9

pH vs SO2, explain the relationship

In winemaking, when is most effective time to add SO2

Answer 9

More free SO2 in molecular form in lower pH levels

More SO2 needs to be added to wines with higher pH levels

Larger amounts when grapes are crushed, after mololactic conversion, and at bottling

Question 10

What negative effects can SO2 have on wine

What can winemakers do to lower amount of SO2 needed

Answer 10

Full aromas/flavors
Cause wine to taste harsh

• Good winery higiene, good grape sorting - limits
  harmful microbial activity
• Limiting oxygen exposure
• Keeping grapes, must or wine at cooler temps

Question 11

When transporting grapes after harvest what are grapes vulnerable to

How to limit and minimixze these threats

Answer 11

Oxidation, ambient yeasts, acetic acid baterial (alcohol to vinegar)

Ways to minimize

• Night harvest, or sunrise to keep cool temps
• SO2 addition
• Cold storage room once recieved at winery
• Sanitizing harvest equipment/bins
• Small crates, minimize crushing

Question 12

When grapes are recieved at the Winery what are ways to move them around

what are the steps to reception and the goals of these steps

Answer 12

conveyor belt, fork lift, pallet truck

• Chilling (reduce oxidation, spoilage: use heat exchangers, or refrgeration units. Night harvest)
• Sorting (for desired wine quality and price based on number of factors)
• Destemming (usually upon arrival at winery, stems contain tannin, underipe stems create bitterness green notes in wine)
• Crushing

Question 13

What is the goal of chilling

What methods of chilling grapes are used in reception

Disadvantage

Answer 13

• reduce oxidation, spoilage
• use heat exchangers, or refrgeration units.
• Costly in machinery and energy, Night harvest in warm climates can help

Question 14

What factors are taken into consideration in sorting

Disadvantages

Answer 14

Remove MOG (Material other than grapes), underipe/damaged fruit

• RIpeness of fruit
• How healthy the fruit is
• What the desired quality of and price of wine is
• If any sorting occured in the vineyard
• Physical state of grapes
• Costly in time, labor, and yield (more particular tends to be less fruit)

Question 15

What sorting options for inexpensive or quality wines are there

Answer 15

• So may not require any sorting for inexpensive
• Removing unwanted grapes or bunches while picking
• Hand Sorting - tables, conveyor belt, vibrating belt (before or after desteming, sometimes both)
• Optical sorting - expensive, 100 grape samples, premium and super premium wines

Question 16

What are some examples of grapes or styles that would not be destemmed

Answer 16

• Red wines that use whole bunches (ex Pinot in Burgundy)
• Carbonic Maceration (gamay in beaujolais)
• Whole bunch pressing for some white wines (common in sparkling)

Question 17

Explain Crushing

How it is done now and was traditionally done

Explain “Must”

Answer 17

Beginning of winemaking process, applying enough pressure to break the skins of grapes and release juice

Trasitionally human feet, now machine, usually attached to destemmer, or if whole cluster during punch down

Must is mixture of juice, pulp, skins, and seeds that come out of crusher

Question 18

When does pressing usually occur in White vs Red Winemaking

Goal of pressing white vs red

Answer 18

White Winemaking - before fermentation, usually after destemming
Maximize juice without extracting tannin or seeds

Red Winemaking - Pressed after desired number of days on skins or after fermentation
Patriculrly soft, not to extract extra bitter tanning from soft grape must that has been soaking

Both need soft pressing

Question 19

What different types of presses are there, explain each

Advantages & Disadvantages

Answer 19

Pneumatic Press - ‘Air bag or Bladder press’ - Most common, Cylindrical cage with blandder running down middle or side, bladder fills with air pushing crapes into grates. batch processing
Adv.
Programmed for amount of pressure
Can be flushed with inert gas to protect juice from oixidation
Dis.
High initial investment

Basket Press “Vertical Presses” or “Champagne Presses” - more traditional form, but still used by some
Basket filled with grapes and pressure applied from above, juice runs through gaps or holes in sides, huice collected in tray at bottom, batch processing
Adv
Some winemakers believe to be more gentle
Dis
Smaller loads, more labor intensice
Not sealed, no inert gas to avoid oxygen exposure

Horizontal screw Press - similar to basket, rectangle draining tray, less gentle, batch processing

Continuous Press - screwing mechanism, quicker pressing for large volumes

Question 20

What are Must Adjustments and the goal of Must Adjustments

Are the cateories of corrections to Must that can be taken

Answer 20

Creat more balanced wine, especially if there have been compromizes to the grapes

• Enrichment, Sugar of Chapitalization or Adding Alcohol
• Reducing Alcohol
• Acidification
• Deacidification

Question 21

The Steps of General Winemaking Options after harvesting and before Maturation

Answer 21

1. Oxidation & SO2
2. Transportation to Winery
3. Grape Reception
4. Pressing
5. Must Adjustments
6. Fermentation
7. Malolactic Conversion
8. Post Fermentation Adjustments

Question 22

Explain Enrichment

What can be used

When is Sugar Added

Other Ways of Enrichment

Answer 22

Enrichment is when sugar is added, usually in cooler regions where the grapes do not ripen as much to increase alsohol of final wine
Dry Sugar - also Chaptitalization, beet or cane sugar
Grape Must
Grape Concentrate
RCGM - Rectified Concentrated Grape Must -manufatured flavorless syrup

Usually added suring fermentation because yeast is active and can cope better with additions

Sugar can be concentrated in must by removing water, reverse osmosis, vaccum evaporation, or cryo extraction (all are more expensive although cryo the least, either for equipment costs or reduced yields)

Question 23

Explain Reducing Alcohol at this step

Advantage and Disadvatage

Answer 23

Lower potential alcohol, can be done by adding water, perhaps warmer climate where sugar concentration is increased in grapes

Only leagal in some counties
Dilutes grapes aromas and flavors

Other ways would be post fermentation

Question 24

Explain why you mould need acidification

Which acid(s) are used

When would acidification occur

Answer 24

In warm climate without cooling influences, Malic acid would drop rapidly as grapes ripen, wine could lach freshness

Used to lower pH
For inexpensive - mid priced - premiums wines in warm climates

Typically addition of tartaric acid
Other grape acids:
- Citric 
- Malic
- Lactic

Before, During or After Fermentation but winemakers believe better integration before and starting with lower pH

In EU not allowed to hapitalize and Acidify

Question 25

Explain why you would need deacidification How is deacidification done when would deacidification occur

Answer 25

In cool climates where grapes are picked before fully ripe Adding calcium carbonate (chalk) or potassium carbonate forms tartrates lowering acid Hightech option is ion exchange - cosiderably expensive, must be legal Take Malolactic conversion into play for acid

Question 26

Explain why you would need to add tannin How can tannin be added when would Tannin addition occur

Answer 26

To clarify must, stablize color, improve mouthfeel Powdered tannin Before fermentation or before maturation

Question 27

What decisions should be made or what is required for Alcoholic fermentation

Answer 27

1) Yeast a) Ambient Yeast b) Cultured Yeast 2) Temperature a) Cool 12 - 16C (54-61F) Fresh fruity whites and rose b) Mid 17-25C (63-77F) Easy fruit reds, low tannin, less fuirty whites (barrel fermented whites) c) Warm 26-32C (79-90F) Red wines high concentration pronounced tannin, loose some fruit aromas 3) Fermentation vessels a) Stainless steel b) Concrete c) Wood

Question 28

Define Alcoholic Fermentation

Answer 28

Conversion of Sugar into Alcohol (ethanol) and Carbon Dioxide carried out by yeast in absence of oxygen Produces heat which has to be managed

Question 29

Define Yeast

Answer 29

collective term given to group of fungi that convert sugar into alcohol and effect flavor/aroma characteristic. Need oxygen to multiply quickly, then convert to alcohol when oxygen is gone

Question 30

What conditions do yeast need to produce alcohol What is most common Yeast

Answer 30

- Viable temp range - Access to yeast nutrients - Nitrogen - Absence of Oxygen Saccharomyces Cerevisiae

Question 31

Aside from Alcohol, CO2 and heat what does Alcoholic Fermentation produce?

Answer 31

- Volatile Acidity (VInegar, nail polish) - Wine Aromatics (Thiols, Terpenes) - Aromatics created by yeast (banana) - Undesireable sulphur reductive aromatics (rotten eggs, rotten cabbage) - Acetaldehyde (bruised apple, paint thinner) - Glycerol, increases body of wine

Question 32

Where is ambient yeast (wild yeast) found Advantages and Disadvantages to using

Answer 32

- Present in vineyards and winery- includes range of species - tends to die after 5% alcohol Adv - Adds complecity from multiple yeast species producing different aroma compounds - Costs nothing to use - Can be unique to a place or region - Can be used to market wine Dis - Fermentation may start slowly (build up of VA, Spoilage Aromas leading to off flavors) - Fermenting to dry may take longer, risk of stuck fermentation - Consistent product not guaranteed

Question 33

Where is cultured yeast (selected or commercial yeast) from What do you need to use it Advantages and Disadvantages to using

Answer 33

Selected in labs, grown for volumes suitable for sale Selected strains of singel Saccharomyces Cerevisiae To use Cool must so ambient yeast is not fermenting or Add SO2 to surpress ambient yeast then Starter batch of fermenting cultured yest, and the rest of cultured yeast Adv - Reliable fast fermentation to dryness - Due to speed less VA, spoilage organisms and bacteria, security of clean complete ferment - Consistent product vintage to vintage - Can shoose for style with such large selections to pick from Dis - Some believe cultured yeast leads to certain similarity of fruit expression "Industrial Wine" - Adds cost of using commercial product

Question 34

Explain what temperatures you need for Fermentation What is temp slows or stops fermentation How can temp be controlled

Answer 34

a) Cool 12 - 16C (54-61F) Fresh fruity whites and rose b) Mid 17-25C (63-77F) Easy fruit reds, low tannin, less fuirty whites (barrel fermented whites) c) Warm 26-32C (79-90F) Red wines high concentration pronounced tannin, loose some fruit aromas Above 35C (95F) is where yeast struggles to survive Options of controlling temp - Fermentation rooms - warmer or cooler - Fermentation vessel may have temp control installed - Water or Glycol jackets (or inserts) that surround the vessled (or inserted) Pumping over releases heat

Question 35

What are different types of Fermentation Vessels

Answer 35

- Stainless - Concrete - Wood Other - Plastic Vessels - Terracotta (amphorae) - Qveri (georgia) - Tinaja (Spain)

Question 36

What are Advantages and Disadvantages to stainless steel as fermentation vessels

Answer 36

Adv. - Most common - Easy to clean - Many sizes enables temp control - Neutral Vessel, protects wine from oxygen, dont add flavors - High level of Mechanization possible Dis - Costly initial investments of tanks and computer temp control systems

Question 37

What are Advantages and Disadvantages to Concrete as fermentation vessels

Answer 37

Adv - Were inexpensive last century - High thermal inertia, maintain even temp - New eggs permit natural lees stirring Dis - Eggs are very costly

Question 38

What are Advantages and Disadvantages to Wood as fermentation vessels

Answer 38

Adv - Retains heat well - Allow small amount of oxygen (can be good, expecially in red wine) - Can be reused many times (inexpensive long term) - White wines can be fermented in them Dis - Red wines difficult to ferment to to need of cap management - Harbours bacteria and spoilage organisms, hard to clean

Question 39

What is Malolactic Conversion How did it used to happen vs How What conditions encourge and prevent it

Answer 39

Lactic Acid Bacteria converts MAlic Acid into Lactic acid and CO2. Typically after fermentation Historically occured in spring when barrels warmed in cellar, now Cultured lactic acid bacteria is added Encourages 18-22C (64-72F) Moderate pH - 3.3- 3.5 Low SO2 Discourages Temp below 15C (59F) low pH moderate SO2 - can add enzyme lusozyme which kills lactic acid bacteria - Can filter out lactic acid bacterial - Move wine to another part of winery avoiding spread of lactic and bacteria

Question 40

What are the outcomes of Malolactic Conversion

Answer 40

- Reduction in acidity, rise in pH, if already low in acid then smoother, softer wine - Some color loss in reds - Greater microbial stability, having it go through malo prevents from spontaneously going through malo later - Modification in flavor - increase VA, slight loss of fruit character, adds buttery conponent

Question 41

What are Post Fermentation adjustments winemakers can do before maturing, packaging and finishing the wine Why would you do these steps

Answer 41

Goal is to only make necessary small adjustments post fermentation to not upset balance - Removal of Alcohol (for reduced alcohol wine) or to adjust alcohol level marginally a) Reverse Osmosis b) Add Water c) Spinning Cone - Correcting Color (if permitted)

Question 42

When Removing Alcohol in Post fermentation adjustments what are 3 ways to do this Advantages and disadvantages

Answer 42

``` 1) Adding Water Adv. Simple, inexpensive, adds quantity DIs. Reduces intensity of flavor ``` 2) Reverse Osmosis - type of crossflow filtrationthat removes flavourless permeate pf alcohol and water, which can be distilled to remove alcohol, then blended back. Adv Common, thurough, doesnt change flavor/aromas as much Dis Equipment costly even in rented ``` 3) Spinning Cone - device that first extracts volatile aromas from wine, then removes alcohol. Aromas compounds blended back into wine Adv Used for large volume production Dis Specified laws Lower quality generally ```

Question 43

What are ways to change color during post fermentation adjustments

Answer 43

1) Reduce unwanted color tints - Fining the wine 2) Enhance color intensity (high volume) - Adding small amounts of grape derived coloring agents (ex MegaPurple)