Sparkling Wines

Question 1

Explain why a producer of traditional method sparkling wines requires grapes with relatively low sugar levels.

Answer 1

The producer aims to produce a base dry wine of 10-11% abv to allow for an increase in alcohol during 2nd fermentation of 1.2-1.3% abv High levels of acid associated with low sugar levels are required for a refreshing style of sparkling wine.

Question 2

Name and describe the process by which traditional method sparkling wines acquire flavours of bread and biscuit

Answer 2

1. Yeast autolysis
2. Once second fermentation the yeast dies and forms sediment of lees in the bottle.
3. Dead yeast cells break down and release chemical compounds into the wine.
4. The longer wine spends in contact with the dead yeast cells,the more intense the flavours

Question 3

Identify and describe two ways of making sparkling wines sweet

Answer 3

Method 1
Use of liqueur d’ expedition
Adding a wine sugar solution to a dry sparkling wine
The amount of sugar in the solution will determine the level of sweetness.

Method 2
Tank method or Asti Method
Fermentation is stopped early before all the sugars are fermented
Fermentation is stopped by chilling the wines
Wine is filtered to remove the yeast and bottled immediately.

Question 4

Describe the method used to produce this wine (7 marks) and how it affects the style of 
wine produced (3 marks)

Martini
Asti

Answer 4

The juice is chilled and stored until needed. When it is required, the juice is warmed and the fermentation takes place in pressurised tanks. Initially, CO2 is allowed to escape. Part way through the tank is then sealed so that CO2 is retained. The ferment continues until the alcohol has reached approximately 7% abv and the pressure 5 to 6 atmospheres.
The fermentation is stopped early by chilling the wine, which is then filtered under pressure to remove the yeast. The wine is bottled for immediate sale
How it affects the style of wine produced:

Asti is a sweet and low alcohol (due to the interrupted fermentation) and sparkling because
CO2 is retained. The lack of autolysis retains the aromatic character resulting in a youthful, fruit-forward wine for early consumption.

Question 5

Describe how to open a bottle of this wine (5 marks)

Answer 5

Chill wine to correct temperature to reduce pressure. The remove foil and loosen wire
cage, while holding cork securely. Tilt bottle at 30 degrees and whilst gripping cork, turn
bottle, not cork. Ease cork slowly out of bottle releasing the pressure with quiet phut, not
explosion

Question 6

Account for reason that tank method wines often have little/or no contact autolytic character?

Answer 6

Tank method sparkling wines are produced via two fermentations such as traditional method but the second fermentation which is initiated by yeast, sugar, yeast nutrients and clarifying agents (also known as liqueur de tirage) occurs in sealed tank. As soon as this second fermentation is complete the sparkling wine is filtered and remove the yeast lees. As it does not spend any extended time on the lees it will show little/no autolytic character (such as bread, dough) and will be dominated by primary flavors and aromas.

Question 7

Why are wines produced via the Asti method sweet or semi-sweet?

Answer 7

Asti method sparkling wines are produced via one fermentation in a sealed pressurized tank. Initially C02 is allowed to escape but part way through the fermentation, the tank is sealed to absorb the C02 into the wine. The single fermentation continues to approx 7%abv and the pressure is 5-6atmospheres when it is stopped early by chilling the wine. This ensures that not all the sugar in the must has been converted to alcohol leaving residual sugar in the winemaking it sweet or semi-sweet.