1. Standard Options in Sparkling Winemaking

Question 1

What type of climate is ideal for sparkling wines, and why?

Answer 1

Cool climates where grapes struggle to ripen. Grapes are just-ripe in flavor but retain acidity required for high-quality sparkling wines. Sugar accumulates slowly, giving still base wines with low alcohol (9-11% abv). Necessary because 2nd fermentation used in many methods adds 1-2% abv

Question 2

What geographic conditions will result in cool climates? Give an example of each

Answer 2

High latitude - Champagne, England, Tasmania
Near the coast - Sonoma
High altitude - Trentodoc

Question 3

What type of sparkling wines are better suited in warmer climates?

Answer 3

Short-aged wines (e.g. tank method or with short time on lees) where riper fruit flavors and lower acidity are desirable

Question 4

Why is Chardonnay well suited to the production of autolytic styles of sparkling wine?

Answer 4

Subtle apple and citrus aromas and flavors compliment the biscuit/pastry aromas from yeast autolysis. Early ripening is an asset in cool conditions and it also retains high levels of acidity and low levels of alcohol needed, while avoiding under-ripe flavors.

Question 5

What threats is Chardonnay susceptible to?

Answer 5

1. Spring frosts
2. Coulure & millerandage
3. Grapevine yellows
4. Botrytis in wet periods before harvest. ‘
5. Powdery mildew

Question 6

Why is Pinot Noir suited to cool climates? What vineyard threats is it vulnerable to?

Answer 6

It is early budding and early ripening.
Prone to coulure. Thin-skinned and more disease prone (downy mildew especially, powdery mildew, botrytis, fan leaf and leaf roll)

Question 7

What do Chardonnay and Pinot Noir each contribute to a sparkling wine blend?

Answer 7

Chardonnay - apple, citrus flavors and high acidity

Pinot Noir - body

Question 8

What factors in a grape variety can influence the style of the wine?

Answer 8

1. Intensity of aromas (aromatic or neutral)
2. Ability to retain acidity while ripening
3. How the base wine response to autolysis where applicable (e.g. Chardonnay becomes creamy, Xarel-lo becomes toasty/smoky).

Question 9

Why are grapes for sparkling wines grown at higher yields than grapes for still wines?

Answer 9

High acid, low potential alcohol and delicate flavors are desirable in most sparkling wines, and these characteristics are better achieved at high yields.

Question 10

Does harvesting for sparkling wine production occur earlier or later than still wine production? Why?

Answer 10

Earlier

1. In order to achieve high acid, low alcohol profile desired for sparkling wines
2. Grapes less likely to be on the vine as rainy autumn weather starts, reducing risk of fungal diseases

Question 11

What are the advantages and disadvantages of hand-picking grapes?

Answer 11

Advantages:
1. Permits sorting at picking and post-harvest selection to exclude disease-infected grapes
2. Minimizes splitting and crushing of grapes, as well as subsequent oxidation of juice along with extraction of phenolics (including color, tannin)
Disadvantage:
1. Slow
2. Labor-intensive
3. Expensive

Question 12

What are the advantages and disadvantages of machine harvesting?

Answer 12

Advantages:
1. Faster - for large estates the grapes are more likely to be picked at the desired point of ripeness
2. Cheaper
3. Permits night harvesting, delivering cooler grapes - reduces oxidation.
Disadvantages:
1. Can rupture skin of grapes, resulting in phenolic extraction and oxidation.

Question 13

Why is whole-bunch pressing often practiced for premium traditional method sparkling wines?

Answer 13

One of the gentlest forms of pressing, providing juice that is low in solids and phenolics (including tannins and anthocyanins). Stems help create network of channels for juice to flow, minimizing pressure required.
Disadvantage - more time consuming than using crushed grapes because fewer bunches can be loaded into press.

Question 14

Why are phenolic compounds undesirable in sparkling wines?

Answer 14

They can make wine taste bitter and feel coarser on the palate.

Question 15

How is press fraction juice different from free run juice?

Answer 15

Press fraction juice is higher in phenolics, solids and pH than free run juice. Wines made from press juice tend to mature faster, so useful in wines with short maceration made for immediate consumption.

Question 16

What vessel is usually used for primary fermentation and at what temperature does it take place?

Answer 16

Most takes place in stainless steel tanks to allow large volumes to be fermented with temperature control and for ease of cleaning tanks before/after. 57-68F typical for primary fermentation to retain fruit flavors but ensure temp not too cold for yeast.

Question 17

What type of yeast is used for primary fermentation? What are considerations in making the selection of yeast?

Answer 17

Cultured yeasts that can ferment reliably to dryness in high acid and low pH conditions typically used. Some strains promote certain flavors in wines (e.g. thiols, esters). May be positive for tank method wines based on fruity flavors. Pronounced primary flavors generally not wanted in autolytic styles - may compete with flavors from autolysis. Use neutral yeasts for these.

Question 18

What are the considerations related to secondary fermentation for yeast selection?

Answer 18

Stressful conditions of secondary fermentation considered:

1. Must be able to start fermenting with 10% abv alcohol, which is too high for many yeasts
2. Must be able to start fermenting w/ low pH
3. Continue fermenting through low temperature, high pressure and poor availability of nutrients
4. Must allow rapid autolysis and easy flocculation (clumping together).

Question 19

What is one of the most common cultured yeasts used in sparkling wine production?

Answer 19

Prise de mousse (EC1118)

Question 20

Why is malolactic conversion often used for sparkling wines?

Answer 20

1. Reduce acidity in excessively acidic wine
2. Enhance texture - lactic acid has a creamier texture than other acids
3. Risk it could take place spontaneously in bottle during 2nd fermentation which would be problematic because it can turn wine hazy, which is difficult to fix in bottle.

Question 21

Why are buttery flavors not present for sparkling wines that undergo malolactic conversion?

Answer 21

Diacetyl, which gives the buttery flavor, is metabolized by yeast during secondary fermentation.

Question 22

If a winemaker doesn’t desire malolactic conversion, what do they do to prevent it from spontaneously occurring during 2nd fermentation in the bottle?

Answer 22

Sterile filtration

Question 23

What are considerations if a winemaker wants to mature base wine in oak before blending?

Answer 23

Sparkling wine magnifies the aromas and flavors of oak (vanilla, toast, spice) and so where new oak is used, it will only be for a small proportion of a blend. Most often seasoned barrels are used. If producer wants fruity style, oak not used.

Question 24

Discuss the purposes of blending for sparkling wines

Answer 24

1. Balance - different varietals contribute different aroma/flavor/body/acidity components to wine
2. Consistency - e.g. non-vintage blend
3. Style - desired house style may vary based on price point and suitability for aging
4. Rose’ - some made by blending red/white base wines
5. Complexity - by blending different varieties, vineyard sites, vintages, or blending wines that have undergone different treatments (e.g. oak, reserve wines)
6. Minimization of faults - if batch has minor fault can be diluted into larger volume
7. Volume - producers may blend wine from different vineyards to achieve necessary volumes
8. Price - may blend in cheaper grapes with more prestigious ones to keep price affordable

Question 25

What 2 steps are taken for traditional method wines following blending but before secondary fermentation?

Answer 25

1. Stabilizing for tartrates and proteins

2. Clarifying

Question 26

What is liqueur de tirage?

Answer 26

Mixture of wine must, sugar, cultured yeasts, yeast nutrients and clarifying agent such as bentonite or alginate (seaweed extract that facilitates riddling)

Question 27

What are the considerations for the amount of sugar added to the liqueur de tirage?

Answer 27

Amount of sugar depends on level of effervescence required. In most fully sparkling wines, 24g of sucrose per litre added. Yeast converts sugar to alcohol and CO2. CO2 can’t escape from bottle so produces pressure appropriate for sparkling wines - 6 atmospheres. Less sugar added if winemaker wants lower pressure. Sugar doesn’t affect sweetness because yeast ferments to dryness.

Question 28

Why is the selection of yeast used important for secondary fermentation?

Answer 28

Important to select yeast that is able to ferment in unfavorable conditions:

1. Must commence fermentation with existing 9.5-11% ABV
2. Moderate temperature (61F)
3. Low pH (<3)
4. Withstand high pressure generated in bottle fermentation
5. Yeast cells must flocculate readily to produce coarse sediment that can be removed by riddling.

Question 29

What is the primary factor affecting the length of secondary fermentation?

Answer 29

Temperature - stored horizontally “sur latte” at constant temp of 10-12C. a cooler temperature results in slower fermentation, and some claim a more complex finished wine. In many cases the fermentation lasts 4-6 weeks. Stable temp important to maintain yeast viability.

Question 30

What is the process and considerations for lees aging?

Answer 30

Bottles stored horizontally in stacks or metal cages, at temp around 10C. Length of time varies. Min 9 months (e.g. Cava). Typically 15-18 months - autolysis detectable. Length depends on desired style (fresh-fruit vs lees-aged), price that can be attained for wine and financial ability to invest in longer periods of aging.
Benefits derived from autolysis, the enzymatic breakdown of dead yeast cells. Usually lasts 4-5 years but has been known to last up to 10 years. Produces compounds that add biscuit complexity

Question 31

What are the pros and cons of keeping wine on the lees after autolysis finishes?

Answer 31

Pros - anti-oxidative qualities of yeast cells protect wine from oxidation compared to a disgorged wine of same age.
Con - the longer wine kept in this state, the faster it evolves once disgorged. The older a wine is the less it can withstand the shock of disgorgement. Must be drunk soon after release.

Question 32

What is the effect of riddling? What are different methods used?

Answer 32

Process - gradually twisting or rotating bottles while bringing them from horizontal to vertical (cap down) allows lees to flocculate and slowly move to neck of bottle to facilitate removal.
Manual riddling - hand turning - takes up to 8 weeks.
Gyropalettes - take 3-4 days.
If wines need to be stored before disgorgement, stored “sur pointe” - upside down on neck, so lees remain in neck.

Question 33

Discuss the process of disgorgement

Answer 33

Mainly become automated process. Bottles cooled to 45F and necks immersed in bath of frozen brine. Quickly freezes yeast sediment in neck, easing extraction and ensuring it doesn’t fall back into bottle when turned upright.
Cooling also increases solubility of CO2 so reduces likelihood of wine gushing when opened.
Disgorging machine inverts bottle upright, removes crown cap and allows pressure within bottle to eject frozen yeast plug.
Liquer d’expedition added before bottle fitted with cork, muzzle and metal capsule.

Question 34

What is liqueur d’expedition? What is the role of dosage in sparkline wine?

Answer 34

1. A mixture of wine and sugar (sugar called dosage) or RCGM.
2. Tops up bottle where some wine may have escaped during disgorgement and determines final sweetness of wine.
3. Growing trend for Brut Nature (no dosage) and Extra Brut (dosage results in <6 g/l sugar)
4. Role of dosage to balance acidity - especially important in younger wines. Perception of acidity rounds out with age, so older the wine at disgorgement the less dosage needed.
5. At least some sugar usually desired to encourage post-disgorgement aromas - reacts with compounds formed during yeast autolysis - called Maillard reaction. Encourages development of roasted, toasted vanilla aromas - cork-sealed sparkling wine may be stored for extra few months to allow development prior to release.

Question 35

Why was the transfer method developed and what are its benefits?

Answer 35

1. Developed to avoid cost of manual riddling while retaining bready, biscuit notes through autolysis.
2. Reduces bottle-to-bottle variation
3. Generally easier to make final adjustments to wine.
4. Improvements in automated riddling make it less significant, but still offers some cost/time savings for high volume producers.

Question 36

When is the transfer method used in Champagne?

Answer 36

To fill bottles smaller than 37.5cl or larger than 300cL - difficult to riddle.

Question 37

Discuss the process and labeling of transfer method wines

Answer 37

1. Production the same as Traditional up to riddling, including 2nd fermentation in bottle.
2. Since no riddling, fining agents to aid flocculation not included in liqueur de tirage.
3. After lees aging, wine chilled to 0C before discharge into pressurized receiving tanks.
4. Wine sweetened, S02 added, sterile filtering just prior to bottling.
5. Labeled “fermented in bottle”.

Question 38

Discuss the Ancestral Method process

Answer 38

1. Partly fermented must put into bottles - remaining sugar converted to alcohol and CO2, providing effervescence
2. Sugar levels in partly fermented must can be measured accurately so final pressure level can be estimated.
3. Bottle fermentation will generate dead yeast deposit - winemaker’s choice whether to disgorge; more common to keep sediment as part of style.
4. Typically no dosage
5. Since no intervention once bottle sealed, outcome can vary. Fermentation often slows/stops after few months because yeast becomes unviable and lack of yeast nutrients - results in off-dry wine. Fermentation may start back up later - will result in higher pressure and less RS.

Question 39

What is an alternative name for Ancestral Method? What is their aroma/flavor profile?

Answer 39

PetNat (Petillant naturel)
Often low alcohol, slightly cloudy, dry to off-dry, unconventional flavors sometimes compared to cider.
Bottled without additional SO2
Intended for early drinking.

Question 40

What is the benefit of the Tank Method? What are some alternative names for this method?

Answer 40

1. Enables large volumes of sparkling wine to be made inexpensively, quickly and with significantly reduced labor costs compared to traditional method.
2. No riddling, disgorgement, and typically no dosage or long period on lees during 2nd fermentation - all add cost.
3. Wines can be made and released for sale quickly.
4. Preferred when winemaker wants to preserve primary aromas/flavors and doesn’t want autolytic characteristics.
5. Often used for producing fruity wines mad with semi-aromatic or aromatic varieties (e.g. Glera, Muscat)

Question 41

Discuss the process for making tank method wines

Answer 41

1. 1st fermentation 61-64F - retain fresh floral and fruit aromas/flavors, but avoid flavors associated with very low fermentation temps
2. Sugar + yeast added - rapid 2nd fermentation in pressurized (reinforced) tanks - as short as 1 month.
3. 2nd fermentation arrested by cooling wine to 36-40F when desired pressure and RS reached.
4. If removed from yeast lees immediately, sparkling wine will retain fruity aromas/flavors.
5. Wine may be aged on lees (e.g. 9 mos) if lees-matured attributes desired. Temp reduced to 36-40F and use paddles to stir lees to max contact w/ wine. If this is done lose one of main benefits of tank method - fast production
6. End of fermentation or lees contact, wine cold stabilized to precipitate tartrates. Yeast removed by centrifugation or filtration
7. Sugar levels adjusted and SO2 checked and corrected prior to sterile filtration/bottling.
8. Wine chilled to 28F to stabilize and reduce effervescence, then bottled with counter-pressure filler.
9. Bottle filled with chilled wine replacing added CO2 - prevents entrance of oxygen and loss of CO2.

Question 42

What is the Asti Method? Explain the process and how it differs from the method from which it is derived.

Answer 42

1. Variation of tank method
2. Single fermentation
3. Sugar comes from sugar in original must, not later tirage.
4. Must fermented in reinforced tanks
5. During first stages of fermentation, CO2 escapes through valve in tank - part way through valve is closed and CO2 retained - timing depends on pressure and RS desired in final wine.
6. Wine continues to ferment - pressure increases and sugar decreases
7. When desired pressure/RS reached - stop fermentation by rapidly chilling wine and filter under pressure to remove yeast.

Question 43

List the labeling terms for sweetness in sparkling wines and level of RS for each

Answer 43

Brut Nature - 0-3 g/l
Extra Brut-  0-6 g/l
Brut - 0-12 g/l
Off-Dry - 12-17 g/l
Dry - 17-32 g/l
Medium Dry - 32-50 g/l
Sweet - +50 g/l

Question 44

What is the cork composition and closure process?

Answer 44

1. Prior to bottling looks like any other cork but fatter (31mm diameter)
2. Commonly composed of agglomerate cork onto which 2 disks of natural cork glued - impossible to cut a cork of this width from cork tree of appropriate age
3. Cork compressed by machine to half its diameter and inserted into bottleneck. Neck inside diameter 18-21mm - cork remains compressed to 60-70% original diameter - adheres tightly to glass, preventing wine from leaking.
4. Recent technology has removed cork taint from particles - increasing use of technical corks such as DIAM.

Question 45

What are the factors that affect the formation and size of bubbles in sparkling wine?

Answer 45

1. The amount of sugar available to be turned into alcohol and CO2 - more sugar = more CO2
2. Capacity of CO2 to be dissolved in wine, depends on:
   a. grape variety(ies)
   b. health of the grapes (presence of botrytis reduces bubble formation)
   c. winemaking process
3. Length of time on lees - some CO2 lost as time on lees lengthens but produces longer lasting foam
4. Quality of disgorgement process -if well little CO2 lost
5. Time in bottle and type of closure
6. Size and shape of glasses, the way glasses cleaned, temperature of wine when served (lower temp = less CO2 released), how wine is served.