Ch. 5 - Still Wine Production

Question 1

How does Sulphur act as a preservative?

Answer 1

The sulfur combines with oxygen to form sulfur
dioxide (S0 2), which inhibits the growth of both
yeast and bacteria, thereby reducing the likelihood of
premature fermentation and spoilage. It also prevents
the juice from oxidizing and turning brown.

Question 2

What is Free-Run Juice?

Answer 2

the movement of the grapes since harvest has already caused many of the berries to burst open, so a large amount of juice drains out from the press immediately (more if the berries were crushed first). This is known as the “free run” juice and is typically considered to be juice of the highest quality, rich in sugar and low in tannin.

Question 3

What is pomace?

Answer 3

The cake of dry, compressed skins and pips (seeds)
that remains after the final pressing is called pomace.
It is mainly used to make pomace brandies known as mare or grappa.

Question 4

What is a must?

Answer 4

Grape juice that is destined for fermentation is referred to as must.

Question 5

What is acidification?

Answer 5

The process of adjusting low acidity but addition of tartaric acid to bring balance in wine without affecting the flavours is called acidification.

Question 6

What minerals are used for de-acidification?

Answer 6

Potassium or calcium bicarbonate are used for de-acidification.

Question 7

What is chaptalization?

Answer 7

Chaptalization is process which is carried out in marginal growing regions where grapes may fail
to reach optimal ripeness. In this process, sugar is cautiously added to the must to achieve an acceptable alcohol level in the finished wine.

Question 8

What is debourbage?

Answer 8

After pressing, the winemaker may choose to let the juice settle for a day or two before allowing fermentation to begin. This process is called debourbage in French.

Question 9

What is the basic chemical formula for fermentation?

Answer 9

C6H12O6 + yeast –> 2 (C2H50H) + 2 (CO2)+ heat

Question 10

What % of grape sugars are fully converted during fermentation?

Answer 10

Usually only about 90% of the grape sugars are fully converted into ethanol and CO2 before fermentation stops. Most of the rest are broken down into various
transitional products such as glycerol, succinic acid,
acetic acid, lactic acid, acetaldehyde, ethyl acetate,
and other alcohols such as methanol.

Question 11

What temperature during fermentation of white wines is best for retaining delicate fruit and floral aromas?

Answer 11

Cool temperatures between 50°F and 60°F ( 1 ~ l 6°C).

Question 12

At what temperature can the yeast die and cause a “stuck fermentation”?

Answer 12

If the fermentation gets out of control and the liquid goes much above 100°F (38°C), the yeast will likely die and fermentation will stop prematurely.

Question 13

At what alcohol % will fermentation end?

Answer 13

14% abv

Question 14

What is Malolactic Fermentation (MLF)?

Answer 14

Malolactic fermentation is carried out by a particular strain of lactic acid bacteria that decomposes the sharp malic acid in the wine and converts it to lactic acid.

Question 15

Which ester is created during MLF?

Answer 15

An ester known as diacetyl, created as a byproduct of malolactic fermentation, often imparts a “buttery” aroma to wines that have undergone this process.

Question 16

Does MLF occur spontaneously?

Answer 16

It does not ordinarily start spontaneously unless a wine is fermented or stored in barrels that had previously housed the malolactic bacteria; moreover, it can be prevented with S02.

Question 17

What are lees?

Answer 17

After fermentation is complete, the expired yeast
cells and any other solid particles in the wine begin
to sink to the bottom of the tank or barrel. This sediment is known as the lees.

Question 18

What is racking?

Answer 18

The wine is quickly removed from the lees through a

method of clarification known as racking.

Question 19

What is sur lie aging?

Answer 19

The wine is allowed to rest in contact with the lees for an extended period of time. This is known as sur lie aging, which is French for “on the lees.”

Question 20

What flavours does “on the lees” ageing impart to the wine?

Answer 20

As the wine rests on the lees, the dead yeast cells begin to decompose, potentially imparting a yeasty aroma, creamy texture, and increased complexity to the wine.

Question 21

What is batonnage?

Answer 21

To amplify the effects of lees ageing the sediment may even be stirred back up into the liquid in a process known as lees stirring or batonnage.

Question 22

What are the different methods of clarification?

Answer 22

• Racking
• Fining
• Filtering
• Centrifuge

Question 23

How is racking carried out?

Answer 23

Racking, the most basic clarification procedure, uses the action of gravity by allowing the suspended matter to settle to the bottom of the fermentation vessel. The wine is then carefully drawn off the sediment and moved into a fresh container.

Question 24

Which major fining agents are used to clarify wines?

Answer 24

Fining agents include gelatin and egg white, which bind with and remove excessive tannin, and bentonite clay, which attracts and removes proteins.

Question 25

How is filtering carried out?

Answer 25

Filtering involves straining the wine through a barrier
with very fine openings in order to trap any particulates
over a certain size.

Question 26

What is sterile filtering?

Answer 26

With modem technology, filters can eliminate contaminants as small as bacteria. This process, known as sterile filtering, removes all microbes (yeast and bacteria) that could cause spoilage later.

Question 27

How is centrifuge clarification carried out?

Answer 27

A centrifuge is a modern piece of laboratory equipment that uses accelerated gravity to separate
the wine from the heavier solids.

Question 28

What flavours does barrel ageing impart?

Answer 28

Aging wine in oak barrels allows for a slow oxidation that changes the wine and adds complexity. If the wood is new, it can also add touches of vanilla, oak, wood, coconut, toast, or other aromas to the wine.

Question 29

Why is blending carried out?

Answer 29

Blending is particularly important for branded wines, which need to re-create the desired flavor profile of the brand year after year. Aside from achieving consistency, the practice of blending is also employed to develop complexity or balance, or to create a particular style of finished wine.

Question 30

What is cold stabilization?

Answer 30

White wines, particularly those that are crisp and
tart, tend to be quite high in tartaric acid. The extraction of this acid out of solution as tartrate crystals by chilling the wine is called “cold stabilization”.

Question 31

At what temperature is cold stabilization performed?

Answer 31

Cold stabilization is performed at 25°F ( -4 °C), by holding the wine at this temperature for one to three weeks, and racking the wine off of the precipitates.

Question 32

What is a cold soak?

Answer 32

If the winemaker chooses to begin maceration before fermentation, the must is chilled to below 55°F (13°C) in order to postpone fermentation. This technique is called a cold soak.

Question 33

What are the most common methods of cap management?

Answer 33

• Punching Down
• Pumping Over
• Rack & Return
• Rotofermentation

Question 34

What is the French term for Pumping Over?

Answer 34

Remontage

Question 35

How does rack & return differ from pumping over?

Answer 35

Draining the fermenting juice into a separate holding tank before it is returned to the original tank by spraying it over the now sunken cap, resulting in considerably more aeration than a standard pump-over.

Question 36

What is the french term for Rack & Return?

Answer 36

Delestage

Question 37

What is Rotofermentation?

Answer 37

Agitating the fermenting must in a specialized fermentation vessel that either rotates on its own or contains an inner paddle that mixes the fermenting must; this eliminates the need for punching down or pumping over, as the contents are mixed at regular intervals; usually controlled by a computer.

Question 38

What are the fermentation temperatures for red wine?

Answer 38

Light Reds - Pinot Noir - 60°F-70°F (16°C-21 °C)

Heavy Reds - Cabernet Sauvignon - 85°F-95°F (30°C-35°C)

Question 39

What is polymerization?

Answer 39

The slow infusion of oxygen that seeps through the wood and into the wine helps the tannin molecules combine with each other in a process called polymerization.

Question 40

What process is used to mimic the effect of oak-ageing?

Answer 40

A procedure called micro-oxygenation, which involves bubbling a tiny amount of oxygen into the wine in an attempt to simulate the oxidization effects of barrel aging.

Question 41

What style of wine does carbonic maceration produce?

Answer 41

Carbonic maceration generally results in red wines that are low in tannin , brightly colored, and showing
aromas and flavors of tropical fruit and red berries.

Question 42

What is Saignee method of rose production?

Answer 42

Red grapes are crushed, perhaps destemmed, and vatted for a length of time, typically from 2 to 20 hours. Next, a certain amount of the juice is run ( or bled) off to make rose. The remaining juice remains vatted with
the skins and is made into red wine.

Question 43

What different terms are used for rosé wines?

Answer 43

Vin Gris - France
Rosado - Spain
Rosato - Italy
Weissherbst - Germany

Question 44

What are Kosher Wines?

Answer 44

Kosher wine is certified by Jewish religious authorities to conform to biblical laws as “proper” or “fit” (the literal translation of kosher) for consumption by observant Jews.

Question 45

What is Mevushal Wine?

Answer 45

Mevushal wine, a subcategory of kosher wine, is free from limitations on who may handle it. Mevushal wine is briefly subjected to high heat via flashpasteurization,
either as must or as wine, before leaving the winery.