D4.C1. Standard Options in Sparkling Winemaking Flashcards
Why are the cool climates where grapes struggle to ripen are ideal for sparkling wines?
- The grapes are just-ripe in flavour, but retain the acidity
- Base wines have low alcohol (around 9–11% abv), which is important because the second fermentation used in many methods of making sparkling wines produces an additional 1–2% abv
What kind of regions are ideal to grow grapes for sparkling wine
- Regions that are at greater latitudes, such as Champagne, England or Tasmania
- Regions with local cooling influences, such as those near to the coast (Sonoma) or at high altitude (Trentodoc)
The grapes which are grown in warmer areas and have riper fruit flavours and lower acidity can be used to produce which styles of sparkling wines?
For short-aged wines (e.g. those made by tank method or with short time on the lees in transfer or traditional method)
What are the most commonly used grape varieties for making premium and super-premium sparkling wines?
Chardonnay and Pinot Noir
Why is Chardonnay well suited to the production of autolytic styles of sparkling wines
- Its subtle apple and citrus aromas and flavours compliment rather than compete with the biscuit or pastry aromas from yeast autolysis
- Early ripening of flavours is an asset in cool conditions and it also retains the high levels of acidity and low levels of alcohol needed in sparkling wines while avoiding under-ripe flavours
What does Chardonnay bring to the blend in sparkling wines?
- Apple and citrus flavours
- High acidity
Chardonnay is prone to which viticultural hazards and diseases?
- Spring frosts (early budding)
- Coulure and millerandage
- Powdery mildew
- Grapevine yellows
- Botrytis bunch rot
What does Pinot Noir bring to the blend in sparkling wines?
Body
Pinot Noir is prone to which viticultural hazards and diseases?
- Spring frosts (early budding)
- Coulure
- Downy mildew (mostly)
- Powdery mildew
- Botrytis bunch rot
- Fan leaf
- Leaf roll
What are the factors within the grape variety that can influence the style of the wine?
- Intensity of aromas (aromatic or neutral grape variety)
- Ability to retain acidity while ripening
- How the base wine responds to autolysis where applicable, for example, Chardonnay becomes creamy, whereas Xarel-lo becomes toasty and smoky
Why are the grapes for sparkling wines often grown at higher yields than for still wines?
- High acid levels, low potential alcohol levels and delicate flavours are desirable in most sparkling wines, and these characteristics are better achieved by high yields
- In cool, relatively rainy climates, such as Champagne, this can provide some assurance that even if some damaged fruit has to be removed, a reasonable sized crop can still be harvested
What is the priority of training and trellising techniques used to produce grapes for sparkling wines?
To obtain clean, healthy fruit
How can diseased fruits affect the taste of sparkling wines?
- The perception of any off flavours from diseased fruit can be enhanced by the effects of effervescence in the wine
- Laccase, released by botrytis-infected grapes can cause serious oxidation
What are the advantages of picking the grapes early for producing sparkling wine?
- To achieve the high acid, low alcohol profile
- Early picking also means that the grapes are less likely still to be on the vine as rainy autumn weather starts, reducing risk of fungal disease
Which factors determine the type of harvest for the sparkling wines?
- Location
- Wine laws
What are the advantages of hand-harvesting for sparkling wines?
- Sorting at picking
- Post-harvest selection to exclude disease-infected grapes
- Hand picking and collecting in small crates minimise the splitting and crushing of the grapes and oxidation of this juice along with extraction of phenolics
What are the disadvantages of hand-harvesting for sparkling wines?
- Slow
- Labor intensive
- Expensive
What are the advantages of machine-harvesting for sparkling wines?
- Faster
- Cheaper
- Diseases or damaged grapes can be removed by hand just prior to machine harvest (increases the cost)
- Permits night-time harvesting (oxidation is slowed down)
What is the disadvantage of machine-harvesting for sparkling wines?
It can rupture the skin of the grapes, resulting in phenolic extraction and oxidation
Why is whole-bunch pressing is often practised for premium traditional method sparkling wines?
- It is one of the gentlest forms of pressing providing a delicate juice that is low in solids and phenolics (including tannins and the anthocyanins)
- The stems also help to create a network of channels through which the juice can flow easily, minimising the pressure required
What is the disadvantage of using whole bunches for the production of sparkling wines?
Fewer bunches can be loaded into the press at any one time compared to crushed grapes, and therefore this process is more time consuming
Why should the pressing should be performed as quickly and gently as possible, especially for the black
skinned grape varieties for the production of sparkling wines?
It minimizes the maceration with and extraction from the skins, which would bring unwanted colour and tannins
Which types of presses are used for the production of sparkling wines? Why?
Both pneumatic and basket presses are commonly used, due to their ability to press very gently
Why is it common to split the juice into different press fractions?
- The different press fractions can make useful blending options
- Wines made from press juice tend to be faster maturing, and therefore this fraction can be useful in wines with a short maturation that are made for immediate consumption
What is the next step after the pressing, before the fermentation process begins for sparkling wines?
- The juice is clarified
- Winemaker can choose any of the options available for clarification when making still white wines
What can be done, if the press juice has excessive tannin or color?
Fining (e.g. with casein, gelatine or PVPP [polyvinylpolypyrrolidone]) maybe used
What is the typical fermentation temperature range for the primary fermentation of sparkling wines? Why?
- 14–20°C
- To retain fruit flavours but ensure the temperatures are not too cold for the yeast
Why is the environment stressful for the yeasts during the primary fermentation of the sparkling wines?
Low pH of the juice makes the environment quite stressful for yeast
What is the preferred vessel for the primary fermentation of the sparkling wines? Why?
- Stainless steel
- It allows large volumes to be fermented with temperature control
- Ease of cleaning the tanks before and after fermentation
What kind of yeast is preferred for the primary fermentation of the sparkling wines?
Cultured yeasts that are able to ferment reliably to dryness in high acid and low pH conditions
Do the yeast used for the primary fermentation differ according to the style of the sparkling wine?
Yes, Some strains of yeast can promote certain flavours in the wines, for example thiols or esters. This may be positive in tank method sparkling wines that are based on fruity flavours.
On the other hand, pronounced primary flavours are generally not wanted in autolytic styles of wine as they may compete with the flavours from autolysis so these wines will be made using a neutral yeast that does not enhance these flavours
What type of yeasts are used for the second fermentation of sparkling wines?
It is common to use the same yeast for both the first and second fermentation
Why choosing of the yeast is important especially for the second fermentation of the sparkling wines?
Because during second fermentation, the yeast must be able to start fermenting in alcoholic conditions (10% abv is too high for many yeasts) with low pH, and continue fermenting through low temperatures, in high pressure and with poor availability of nutrients
What is “Prise de mousse’ ?
It is one of the most common cultured yeasts used in sparkling wine production (EC1118)
Is malolactic conversion used during the production of sparkling wines?
Yes, it may be used to reduce acidity in an excessively acidic wine and also can be used to enhance texture
Why are the buttery flavours found on white wines that have undergone malolactic conversion are not typically found on sparkling wines?
Because, diacetyl, which gives the buttery flavour, is metabolised by the yeast during the second fermentation
Why wine should be sterile filtered, if malolactic conversion is not desired?
If malolactic conversion does not take place after primary fermentation, there is the risk that it could take place during the second fermentation. This is problematic for traditional method wines as it can turn the wine hazy, which would be difficult to rectify in the bottle
What is LALVIN DV10?
It is a commercial yeast produced by Lallemand Company LALVIN which claims an ability to work in low pH, high total SO2 and low temperature situations and have neutral character which enables subtle primary fruit to be clearly expressed
Why new oak is used only a very small proportion of the blend in sparkling wines, if used?
Because, the aromas and flavours of oak (vanilla, toast and spice) are usually magnified in the sparkling wines
In which style of sparkling wines, oak is not used?
If the producer is creating a fruity style of wine (e.g. Prosecco or Asti)
What are the blending options for sparkling wines?
- Wines from different vineyard sites
- Wines from different varieties
- Wines from different vintages
- Wines that have undergone different winemaking techniques
What are the purposes of blending in sparkling wines?
- Balance
- Consistency
- Style
- Complexity
- To make rosé wine
- Minimising faults
- Volume
- Price
Which winemaking practices are required after the blending of the wines, before the second fermentation of sparkling wines?
- For traditional method wines, the final blend should be stabilised for tartrates and proteins before being bottled for second fermentation
- For all methods of production for sparkling wine, base wines should be clarified before second fermentation
Where does the second fermentation occur in the Traditional Method sparkling wines?
In the same bottle in which the wine is later sold
What is liqueur de tirage?
It is a mixture of wine and/or must, sugar, cultured yeasts, yeast nutrients and a clarifying agent such as bentonite and/or alginate
What does the amount of sugar in liqueur de tirage depend on?
The degree of effervescence required
How much sugar is added in most of the fully sparkling wines?
24 g of sucrose per litre
What is the amount of increase in alcohol by addition of 24 g of sucrose for the second fermentation?
1.5% abv
What does the winemaker do, if he/she wants to produce a sparkling wine with lower pressure?
Puts less sugar
How does the amount of sugar in liqueur de tirage affect the final sweetness of the sparkling wine?
The sugar added at this stage does not affect the final sweetness of the wine as the yeast ferment the wine to dryness
What is the second fermentation called in French?
Prise de mousse (capturing the sparkle)
What should be the properties of yeasts used for the second fermentation of the sparkling wines?
- They should have aptitude for commencing fermentation in wine with 9.5–11% abv, a moderate temperature of around 16˚C and pH values often below 3, and later withstanding high pressure as it completes fermentation in the bottle
- Yeast cells must also flocculate readily to produce a coarse sediment that can be efficiently removed by riddling
What is “sur latte”?
Bottles are stored horizontally at a constant temperature of approximately 10–12˚C during the fermentation.
What is the usual length of secondary fermentation for sparkling wines?
4–6 weeks
What is the main factor that determines the length of second fermentation for sparkling wines?
Temperature
In which conditions are the bottles stored after the second fermentation is finished for the traditional method sparkling wines?
The bottles can be stored horizontally in stacks or in metal cages, at temperatures of around 10˚C
After how many months, do the effects of autolysis become detectable?
15-18 months
Which factors affect the duration of lees aging?
- Style sought
- Price that can be attained
- Financial ability to invest in longer periods of lees ageing
How long does autolysis continue?
Autolysis usually continues for four to five years but has been known to last for ten years
What is the advantage and disadvantage of keeping the wine on lees after the autolysis has finished?
- The anti-oxidative qualities of yeast cells protect the wine from oxidation, in comparison to a disgorged wine of the same age
- However, the longer a wine is kept in this state, the faster its evolution once disgorged. This is because the older a sparkling wine becomes, the less it can withstand the sudden shock of oxygen at disgorgement
What does “RD” mean on the label of a sparkling wine?
- Recently disgorged
- It is intended to be drunk soon after release
What are the options for remuage (riddling)?
- Pupitres
- Gyropalettes
What are the advantages of using gyropalettes?
- Manual riddling takes up to eight weeks to complete, while riddling using gyropalettes takes three to four days
- Less workforce needed
How are the traditional method sparkling wines stored if they have to be stored before they are disgorged?
They are stored upside down on their necks (sur pointe) so that the lees remain in the neck of the bottle
How is disgorgement process perrformed?
- The bottles are cooled to approximately 7˚C and the necks are immersed in a bath of frozen brine
- The disgorging machine inverts the bottle (so that it is now upright), removes the crown cap and allows the pressure within the bottle to eject the frozen yeast plug
- Liqueur d’expédition is added before the bottle is fitted with a cork, wire muzzle and metal capsule
What is the advantage of cool temperature during disgorgement?
Cooling also increases the solubility of carbon dioxide and so reduces the likelihood of the wine gushing
upon opening
What is the liqueur d’expédition?
It is mixture of wine and sugar or RCGM
What is “dosage”?
The sugar in the liqueur d’expédition
What are the functions of the liqueur d’expédition?
- Tops up the bottle where some wine may have escaped during disgorgement
- Determines the sweetness of the final wine
What is the role of dosage in sparkling wines?
To balance acidity
Why the older the wine is, at disgorgement, the smaller the dosage required?
The perception of acidity rounds out with age
What is Maillard reaction?
- It is the process where the sugar in the liqueur d’expédition reacts with compounds formed during yeast autolysis
- This encourages the development of roasted, toasted vanilla aromas, and the cork-sealed sparkling wines may be stored for an extra few months to allow the development of these aromas before release onto the market
When and why is the transfer method developed for the production of sparkling wines?
- In 1940s
- To avoid the cost of manual riddling while retaining the bready, biscuit notes attained through yeast autolysis in bottle
What are the advantages of transfer method when compared with traditional method?
- Reduces bottle-to-bottle variation
- Easier to make final adjusments
Why did the transfer method become less significant in time?
Due to advancements in automated riddling
Transfer method is the method of choice for which kind of sparkling wines in Champagne and other regions?
To fill bottles smaller than 37.5 cL and larger than 300 cL, as these sizes are difficult to riddle
What is the difference between the liqueur de tirage used in traditional method and transfer method?
Since riddling does not take place, fining agents to aid flocculation do not need to be added within the liqueur de tirage in transfer method
What are the steps performed after second fermentation for transfer metod?
- Wine is chilled to 0˚C before discharge
- Bottles are opened by a transfer machine and the wine is poured into pressurized receiving tanks
- The wine is usually sweetened, SO2 is added, and sterile filtering is carried out just prior to bottling
How can you differentiate a traditional method sparkling wine and transfer method one by looking at the back label?
The back labels of such wines may state “Fermented in the bottle” rather than “Fermented in this bottle”
Describe the ancestral method for producing sparkling wines
In this method, partly fermented must is put into bottles and the remaining sugar is converted into alcohol and CO2, providing the effervescence
How can the final pressure in a sparkling wine be estimated for ancestral method sparkling wines?
By measuring the sugar levels in the partly fermented must
Are the bottles of ancestral method sparkling wines disgorged?
It is a winemaker’s choice whether to disgorge and fill up the bottles or, more commonly, to keep the light sediment as part of the wine’s style
Is dosage added to ancestral method sparkling wines?
No
What is the disadvantage of ancestral method for producing sparkling wines?
Since there is no intervention in the fermentation process once the bottle has been sealed, the outcome can vary
When and why does the fermentation stop in the ancestral method sparkling wine bottles?
A few months because the yeast becomes unviable after this time and due to a lack of yeast nutrients, resulting in an off-dry wine
What happens if the fermentations begins again later in the ancestral method sparkling wine bottles?
These bottles will have higher pressure
and less residual sugar
What are the properties of PetNat wines?
- There are no set regulations
- Often low in alcohol
- Slightly cloudy
- Dry to off-dry with unconventional flavours sometimes compared to cider
- Bottled without additional SO2
- Intended for early drinking
What are the other names for tank method for sparkling wines?
- Cuve Close
- Charmat
- Martinotti
Why can the sparkling wines produced by tank method be made inexpensively than traditional method?
- Large volume can be produced
- Quicker: No long period on lees
- Less workforce: No riddling, no disgorgment, no dosage
When is tank method preferred for making sparkling wines?
When the winemaker wants to preserve the primary aromas and flavours of the grapes and does not desire autolytic characteristics
Which type of grape varieties are preferred for making sparkling wines?
Semi-aromatic (e.g. Glera) or aromatic (e.g. Muscat) varieties
Why is the tank method is often seen as an inferior method of sparkling wine production when compared with traditional method?
The quality of the grapes that are used is often lower
What is the primary fermentation temperature for tank method sparkling wines?
It is typically 16–18°C
Why is the primary fermentation temperature for tank method sparkling wines important?
- It should be cold enough to retain fresh floral and fruit aromas and flavours
- It should also avoid the flavours associated with very low fermentation temperatures
Where does the second fermentation occur for tank method sparkling wines?
In pressurised (reinforced) tanks
What is the length of second fermentation for tank method sparkling wines?
1 month
How and when is the second fermentation stopped for tank method sparkling wines?
This fermentation is typically arrested by cooling the wine to 2−4°C when the desired pressure and residual sugar has been reached
What is the usual next step after the second fermentation is stopped for tank method sparkling wines? Why?
Yeast lees are removed immediately so the sparkling wines will retain the fruity aromas and flavours
If lees-matured attribute is desired for tank method sparkling wines, how is it performed?
The temperature is reduced to 2−4°C and paddles within the tanks are used to stir up the lees to maximise the contact between the lees and the wine
What is the disadvantage of lees maturation for tank method sparkling wines?
Because expensive pressurised tanks are then tied up for months, many of the economic advantages of the tank method are lost
What are the procedures performed after second fermentation for tank method sparkling wines?
- The yeast is removed by centrifugation or filtration
- Sugar levels may be adjusted,
- Sulfur dioxide levels are checked and corrected prior to sterile filtration and bottling
- Wine is chilled to –2°C to stabilise and to reduce the effervescence
- Wine are bottled with a counter-pressure filler
What is “counter pressure filler”.
- Bottle is first filled with CO2 under pressure
- The bottle is then filled with the chilled wine, replacing the added CO2
- It prevents the entrance of oxygen and the loss of CO2
What is the main difference of ASTI method from the tank method?
It produces a sparkling wine in a single fermentation
How is pressure obtained in ASTI method?
During the first stages of fermentation, the carbon dioxide is allowed to escape through a valve in the tank. Part way through the fermentation, the valve is closed and the carbon dioxide is retained
Which factors determines the timing of the closure of the valve to retain CO2 in ASTI method?
Desired amount of pressure and sugar
How is the fermentation stopped after desired amount of pressure and sugar is obtained?
The fermentation is stopped by rapidly chilling the wine and filtering it under pressure to remove the yeast
What is the least expensive method for sparkling wine production?
Carbonation
In which type of sparkling wines, carbonation method is more successful? Why?
- Pétillant, lower pressure wines
- The bubbles may die quickly in a fully sparkling wine
What is the advantage of carbonation method for producing sparkling wines?
Leaving the aroma and flavour characteristics of the base wine intact and thus it is suitable for aromatic or fruity sparkling wines
Why should the base wine be good quality for the carbonation method producing sparkling wines?
Because, any faults will be accentuated by bubbles
What are the EU labelling terms for sweetness in sparkling wines?
- Brut nature: 0-3 gr/L
- Extra Brut: 0-6 gr/L
- Brut: 0-12 gr/L
- Extra-Sec: 12-17 gr/L
- Sec: 17-32 gr/L
- Demi-Sec: 32-50 gr/L
- Doux: 50 + gr/L
What is the tolerance limits permitted for each category for the EU labelling terms for sweetness in sparkling wines?
+/– 3g/L
What is the difference of the corks used for sparkling wines?
Prior to bottling it looks like any other cork but significantly fatter (31 mm in diameter)
Why are the sparkling wine corks commonly composed of agglomerate cork onto which two disks of natural cork have been glued?
- Because it is virtually impossible to cut a cork of this width from a cork tree of the appropriate age
Why is the cork of sparkling wines gain a mushroom shape?
- On corking, the cork is compressed by the machine’s jaws to around half its diameter and inserted into the bottleneck, where it immediately tries to expand back to its original size
- Because the inside neck diameter is 18–21 mm, the cork remains compressed to about 60–70 per cent of its original diameter while the part outside of the bottle expands
What are the other closure options for sparkling wines?
- Technical corks like DIAM
- Crown caps, especially for ancestral method sparkling wines
- Synthetic closure with a resealing mechanism, has been trialled by a few mass-market sparkling wine brands
Which Many factors affect the formation and size of bubbles, the transit of the bubbles through the wine and the way the bubbles collect at the top of the liquid?
The amount of sugar available to be turned into alcohol and CO2
- The capacity of CO2 to be dissolved in wine, which depends on many factors (presence of botrytis reduces the amount of bubble formation) and the winemaking processes
- The length of time on lees: Some CO2 is lost as time on the lees lengthens but longer time on lees will produce a longer lasting foam
- How well the disgorgement process is carried out
- Time in the bottle
- The type of closure
- The size and shape of glasses, the way the glasses are cleaned
- The temperature of the wine when served (the lower the temperature, the less CO2 will be released)
