WINEMAKING TECHNIQUES

Question 1

What yeasts do Vintners tend to use? Which ones don’t they use? Why?

Answer 1

Vintners tend to use commercial yeasts for more stability in winemaking.

Vintners avoid natural, airborne yeasts as they are volatile and bring inconsistent flavours

Question 2

What temperature does red wine fermentation occur?

Answer 2

between 20-32 celsius.

Question 3

At what temperature can yeast die in fermentation?

Answer 3

above 35 celsius

Question 4

What are cap management techniques (4)? explain them.

Answer 4

Punching Down: a method in which the cap is pushed down into the wine with a rod to incorporate colour and tannin into the must.

Pumping over: this method uses a pump from the bottom of the fermentation vessel and pumps the grape must over the cap, incorporating tannins and colour. This method is sometimes avoided as it promotes oxygen interaction.

Rack and Return: This juice is extracted from one vessel into another, leaving the cap behind. It is then pumped back over the cap.

Rotary fermenters: Rotating horizontal tanks, keeping continuous contact of skins and must. Very expensive machines.

Question 5

What is post-fermentation extraction?

Answer 5

Maceration that occurs after fermentation to encourage further extraction of tannin.

Question 6

What are the methods to make rosé wines (3)? explain.

Answer 6

Direct Pressing: A slow crush and press is done to extract some colour and tannin from the skins. Produces light-coloured rosé.

Short Maceration: Short maceration occurs before fermentation. Usually only a couple of days. Fermented at cool temperatures, similar to white wine making.

Blending: Mixing both white and red wines to create a rose. This method is not allowed anywhere in the EU except for Champagne.

Question 7

What is Passerillage?

Answer 7

Grapes are dried on the vine, concentrating sugars. The grape remains botrytis free and this method requires dry heat to avoid rot.

Question 8

What are the 3 styles of whole bunch fermentation?

Answer 8

1). Carbonic Maceration
2). Semi-Carbonic Maceration
3). Whole bunches with crushed fruit

Question 9

Explain Carbonic Maceration

Answer 9

Carbonic Maceration occurs when grapes are placed in a vat in whole, uncrushed bunches. Oxygen is then taken out of the chamber and it is filled with CO2. The CO2 begins a fermentation within the grape called intracellular fermentation. This begins fermentation and once alcohol levels in the grape reach 2%, grapes are removed and begin a regular yeast fermentation

Question 10

What occurs in the grape during Carbonic and Semi-Carbonic Maceration? Explain.

Answer 10

Intracellular fermentation occurs once sufficient amounts of CO2 interact with the grape. The tannins and flavours from the skin move into the grape pulp and change the colour into a dark purple, and create flavours of red fruit, banana and bubblegum. Alcohol levels increase to 2% and then the skins split.

Question 11

Explain Semi-Carbonic Maceration

Answer 11

Semi-Carbonic Maceration occurs when whole bunches of grapes are placed in a vat. The weight of the grapes crushes the clusters at the bottom, releasing some juice. The released grape must generate co2 and pushes oxygen out of the tank. Intracellular fermentation begins and once alcohol levels reach 2% the grapes are removed to begin a yeast fermentation.

Question 12

What would the flavour differences be between carbonic and semi-carbonic maceration?

Answer 12

With Carbonic maceration, all grapes undergo intracellular fermentation and this produces a red-fruit forward wine with bubblegum and banana characteristics.

Semi-Carbonic maceration, not all grapes undergo intracellular fermentation resulting in similar flavour profiles but not as red-fruit, bubblegum and banana forward as a full carbonic maceration.

Question 13

What is whole bunch with crushed fruit fermentation?

Answer 13

Whole bunches with crushed fruit fermentation occurs when whole bunches are placed in a tank with crushed grape must. The bunches are submerged in the must and the cap acts as a barrier for oxygen, thus beginning intracellular fermentation.

Question 14

What is a technique used with the cap during whole bunch with crushed fruit fermentation?

Answer 14

The cap is punched down to interact with grapes undergoing intracellular fermentation, achieving more carbonic characteristics and tannins.

Question 15

What are the 3 main methods of clarification?

Answer 15

FIning, Sedimentation and Filtration

Question 16

What is fining?

Answer 16

The addition of a fining agent into the wine pre-bottling. This agent clumps sediment together which can then be removed from filtering.

Question 17

What is sedimentation?

Answer 17

Sedimentation is the process of slowly pouring the wine into a different vessel, leaving larger bits of sediment behind. (Think racking, decanting)

Question 18

What is filtration? What are the 2 methods?

Answer 18

Filtration is a process in which the particles are removed as wine is passed through a filter.

1). Depth filtration
2). Surface filtration

Question 19

What is depth filtration?

Answer 19

Uses a thick/deep layered material which catches particles as the wine passes through the filter.

Question 20

What is surface filtration?

Answer 20

A very fine sieve-like filter is used to catch particles.

Question 21

What are the 3 forms of stabilization?

Answer 21

1). Tartrate Stability
2). Microbiological Stability
3). Oxygen stability

Question 22

What is the process of Tartrate stability?

Answer 22

Tartaric acids bond and form crystals in wine over time. Winemakers can cause tartrates to form before bottling by cooling the wine down to below 0 degrees celsius for a short period of time. They remove them through the racking/filtration process.

Question 23

What is microbiological stability?

Answer 23

Keeping the number of yeasts and bacteria to a minimum in the winemaking process. Stability is achieved through keeping equipment very sterile.

Question 24

What is oxygen stability?

Answer 24

Removing as much oxygen before bottling and ensuring oxygen doesn’t get into the bottle through the cork/ vessel. Adding C02 or nitrogen into a bottle before filling can achieve oxygen stability.

Question 25

In Germany, what is the addition of Sußreserve? What does it do?

Answer 25

Sußreserve is the addition of unfermented grape must. This is used to generate a higher must weight.