Quiz 01 - Sparkling Wine Production

Question 1

Generally, what type of climate is most suited to growing grapes for sparkling wine production?

Answer 1

Cool climates where grapes struggle to ripen are ideal for grapes destined for sparkling wine production.

Question 2

Why is a cool climate preferable for the growing of grapes for traditional method sparkling wines?

Answer 2

Just ripe fruit characteristics (apple, lemon)
* more delicate so that autolytic flavors are not overwhelmed
Acidity is retained
* Required for balance in final wine
* Required for aging of wine
Slow accumulation of sugars
* low alcohol levels of 9-11% in wine required to allow increase in alcohol produced in second fermentation (1-2%)

Question 3

Given that the grapes for sparkling wine production are grown in cool climates, the sugars in the grapes accumulate slowly.

In what range is the ABV of the base wine usually after first fermentation?

The second fermentation used in many methods of making sparkling wines produces how many percent of additional ABV?

Answer 3

The ABV of the base wine is often between 9 and 11%.

The second fermentation produces an additional 1 - 2% ABV.

Question 4

What are the two most common grape varieties used in the production of super-premium sparkling wines?

Answer 4

Chardonnay and Pinot Noir

Although many other varieties are used across the world to produce super-premium sparkling wines, Chardonnay and Pinot Noir are by far the most common. Both of these varieties are suitable to produce these types of sparkling wines because:

• Both varieties can ripen in cool climates
• Both varieties will retain acidity
• Both varieties respond well to autolysis

Question 5

Name the key reasons why a producer would choose to pick the grapes earlier for sparkling wine.

Answer 5

• fruit characteristics will be more delicate but (just) ripe: it is important that they do not display unripe flavours
• lower sugar level and thus lower potential alcohol
• high acidity is retained
• autumn rain and damage to fruit from fungal disease is avoided

Question 6

True or false?

Destemmed grapes are preferred to whole bunches when pressing in sparkling wine production.

Answer 6

False

Whole-bunch pressing is often practised for premium traditional method sparkling wines.

Question 7

What are the advantages and disadvantages to whole bunch pressing for sparkling wine production?

Answer 7

Advantages:
* It’s a gentle form of pressing which provides delicate juice
* The juice is low in phenolics and tannins and thus bitterness is avoided
* Juice is low in anthocyanins that provide (unwanted) color
* Stems provide channels for juice to flow, minimising pressure required

Disadvantages:
* Can be slow as whole bunches take up more room in the press than crushed grapes
* It is more expensive as the press load is smaller compared to destemmed and crushed fruit

Question 8

When pressing the grapes for sparkling wines, winemakers usually try and minimise the extraction of phenolics as they can make the wine taste bitter and feel coarse on the palate.

Describe the characteristics of the various press fractions used in sparkling wine production.

Answer 8

• Sparkling wines made from the press juice are better suited to styles of wine with short maturation periods and immediate consumption.
• The free run juice is lowest in phenolics, solids and pH.

Question 9

Describe the process of fermentation for traditional method sparkling wines

Answer 9

The temperature of the primary fermentation of sparkling wine production is usually between 14 and 20 °C. - this is so fruit flavours are retained and temperatures are not too cold for the yeast.

The low pH of the juice can stress the yeast. The ideal yeast is able to ferment reliably to create a dry base wine in high acid and low pH conditions.

Commonly, the same strain of yeast will be used for both the 1st and 2nd fermentation, and it will be neutral to retain the flavours of the wine.

The selected yeast also need to be able to ferment at 10% abv for the second fermentation. Rapid autolysis and easy flocculation are also required, as well as being able to ferment at low temperatures, in a high pressure environment, with low nutrient availability.

Question 10

How might malolactic conversion be used during sparkling wine production?

Answer 10

Malolactic conversion can be used to reduce acidity, which can be a problem with cool climate sparkling wines.

Lactic acid is produced during malolactic conversion, which can be creamy in texture.

Malolactic conversion is often used to enhance texture in the base wine as well as to stabilize the wine.

If malolactic conversion doesn’t take place during the first fermentation it can occur during the second fermentation, which is often undesirable: The buttery flavours often associated with malolactic conversion of still wines are rare in sparkling wines because diacetyl (which gives the buttery flavours) is metabolised by the yeast during the second fermentation.

Although malolactic conversion adds stability, it is not always required; in this case the wine will be sterile filtered.

Question 11

Identify the two modifications that may be made to the base wine for sparkling wine production. Then, briefly describe the effects these two methods have on aromas and flavors.

Answer 11

The following two modifications may be considered:

• Maturing the base wine on lees will impact on the aroma and flavor profile of the wine. These associated aromas and flavors will not be desirable for some styles, particularly fruity styles of sparkling wine like Prosecco and Asti.
• Maturing the base wine in oak will impact on the flavor, depending on the age of the oak.

Question 12

Assemblage is the blending of wines, from different vineyard sites, grape varieties, vintages and wines that have undergone different winemaking techniques.

Identify 8 reasons why a sparkling wine might be blended.

Answer 12

1. balance
2. consistency
3. style
4. rosé wines
5. complexity
6. minimisation of faults
7. volume
8. price

Question 13

Describe which objectives a producer may want to achieve by blending wines

Answer 13

Balance:
Aims to provide more body, or higher acidity (often by using different grape varieties or the same variety and warmer/cooler sites).

Consistency:
Particularly important for producers’ NV blend as consumers will expect this to taste the same year to year.

Style:
A producer may want to differentiate how approachable their wines are, or even how age-worthy.

Rosé wines:
Blending of red and white wines to create a particular style.

Complexity:
To create a greater range of flavors or texture.

Minimize faults:
A wine may need to be ‘rescued’ to be saleable; so it’ll be blended with a larger volume of a sound wine.

Volume:
Small vineyard holdings may need to do this by using wines from different vineyards.

Price:
More prestigious or cheaper grape varieties, as well as different press fractions may be blended.

Question 14

What is the name of the addition that’s added to instigate the second fermentation in traditional method sparkling wines?

Answer 14

Liqueur de tirage

Liqueur de tirage is a mixture of sugar, yeast, yeast nutrients and a clarifying agent such as bentonite and/or alginate.

Question 15

Briefly detail the following for each ingredient if the liqueur de tirage respectively:

1. the amount of sugar and the resulting changes to the wine
2. the attributes of the selected yeast for sparkling wine
3. why yeast nutrients are required
4. why a clarifying agent may be needed

Answer 15

1. Approximately 24g/l of sucrose (sugar) is added, this converts into alcohol and CO2. Approximately 1.5% of alcohol is produced and 6 atmospheres (bar pressure) of CO2, which is appropriate for most styles of bottle fermented sparkling wine.
2. The selected yeast needs to be able to commence fermentation in an alcoholic environment (9.5 - 11% abv), low pH, high acid, low nutrient availability and a high pressure environment.
3. The nutrients available will be low after the first fermentation.
4. To aid flocculation of the yeast, aiding riddling.

Question 16

What is …

… the temperature that the bottles are stored at horizontally after the addition of the liqueur de tirage.
… the temperature the bottles are stored at during lees ageing.
… the temperature the bottles are cooled to prior to the necks being immersed in frozen brine for disgorgement.

Answer 16

Temperature that the bottles are stored at horizontally after the addition of the liqueur de tirage:
10–12˚C

Temperature the bottles are stored at during lees ageing.
10˚C

Temperature the bottles are cooled to prior to the necks being immersed in frozen brine for disgorgement.
7˚C

Question 17

How long does secondary fermentation usually last?

Answer 17

4 - 6 weeks

Although producers of more complex wines may choose to ferment their wine for longer at lower temperatures, most wines ferment for this period at a stable temperature to maintain yeast viability.

Question 18

What is the term for the enzymatic breakdown of dead yeast cells that creates biscuity complexity associated with lees ageing?

Answer 18

Autolysis

Autolysis usually lasts 4-5 years, but can go on for as long as 10 years. It creates the complexity and biscuity aromas/flavors associated with lees ageing.

Question 19

What are the legal levels of sweetness in EU labelling terms?

Answer 19

Brut Nature: 0–3 g/L
Extra Brut: 0–6 g/L
Brut: 0–12 g/L
Extra-Sec: 12–17 g/L
Demi-Sec: 17–32 g/L
Sec: 32–50 g/L
Doux: > 50g/L

Question 20

Define the French terms regarding sparkling winemaking (particularly relating to disgorgement processes)

Answer 20

sur latte
The horizontal storage of sparkling wine bottles.

sur pointe
The vertical storage of sparkling wine bottles.

pupitres
The racks used for hand riddling sparkling wine bottles.

remuage
The process of riddling.

Question 21

What does the Maillaird reaction cause in sparkling wines?

Answer 21

The Maillard reaction occurs in sparkling wines, contributing to their flavor and aroma. Here are some key points about the Maillard reaction in the context of wine:

1. Aroma Formation in Sparkling Wines:
   
   • In traditional method sparkling wines, the Maillard reaction plays a role in aroma development.
   • During the second fermentation that occurs in the final wine bottle, the sugar reacts with amino acids formed during autolysis. This interaction generates a myriad of aroma compounds, including those responsible for bready, roasted, and caramel notes.
2. Complex Reaction Cascade:
   
   • The Maillard reaction is a non-enzymatic condensation between reducing sugars (like glucose) and amino acids.
   • It proceeds through a multi-step reaction cascade, resulting in the formation of various aroma compounds.
3. Precursor Species:
   
   • The Maillard reaction relies on the presence of aroma precursors, specifically amino acids and sugars, which are naturally present in wines.
   • These precursor molecules combine to create new compounds during aging and bottle maturation.
4. Factors Influencing the Reaction:
   
   • Low Temperature and Low pH: Sparkling wines are produced under low-temperature (around 15°C) and low-pH (pH 3–4) conditions. As a result, Maillard interactions may not proceed past intermediate stages.
   • Metal Ions: Metal ions may accelerate the Maillard reaction in wines.

In summary, the Maillard reaction contributes to the rich and complex aromas found in aged sparkling wines, enhancing their sensory experience.