5. Still Wine Production

Question 1

How is crushing and pressing different?

Answer 1

No pressure is applied during crushing.

Crushing: skins are broken, juice flows.

Crushing is typical, but not universal. Some wineries will crush and press at the same time.

Question 2

What is free run juice?

Answer 2

This is the grape juice that pours from the vessel prior to pressing.

This juice is highest in sugar and lowest in undesirable tannins.

Some wineries will keep this juice separate for the production of their highest quality wines.

Question 3

What does “pomace” refer to in wine making?

Answer 3

The material remaining after the final pressing. Typically cakey, consisting of compressed skins and pips (seeds).

It is typically plowed back into the fields to nourish the soil.

Question 4

What is “must”?

Answer 4

Grape juice that is on its way to fermentation.

Question 5

Name two common adjustments made to the must prior to fermentation:

Answer 5

Acidification (usually with tartaric acid)

De-acidification (usually with potassium or calcium bicarbonate)

Enrichment (sweetening by adding rectified grape must concentrate / RGMC)

Chaptalization (addition of sugar to the must)

Question 6

Why must a winemaker who chooses to use chaptalization be extremely careful with the level of sugar being added?

Answer 6

Because this sugar is added before fermentation and will increase the level of alcohol in the finished wine.

Question 7

What is Juice Settling? When does this occur?

Answer 7

Post pressing and before fermentation.

This would be done to allow time for the must to fully integrate with its adjustments and/or for some of the solids to settle out of the solution before fermentation.

Known as “debourbage” in French.

Question 8

What is happening chemically during fermentation?

Answer 8

There are roughly 30 successive chemical reactions at play.

Yeast cells attack sugar molecules and break them apart to release energy. (Some of which is given off as heat). The molecules that remain after the yeast has split the sugar apart are ethyl alcohol and carbon dioxide.

Question 9

What is Saccaromyces Cerevisiae?

Answer 9

The most common type of yeasts used for commercial winemaking.

Question 10

What is a typical fermentation temperature for white wines?

Answer 10

50-60 degrees F

Question 11

What happens to the yeast once fermentation is complete?

Answer 11

Once fermentation finishes, the yeast cells (now dead) sink to the bottom of the vessel. These are now known as lees.

If the lees are not removed from the wine, they will begin to decompose and may impart a yeasty aroma, creamy texture, and increased complexity to the wine. This may be amplified by stirring the lees, a process known as batonage.

Question 12

What is batonage?

Answer 12

Stirring of dead yeast cells (lees) in the wine post fermentation. This is done to increase the impact of sur lie aging.

Question 13

What are four common types of clarification?

Answer 13

Racking: Transfer of ‘clean’ liquid to a new vessel. (Repeated). Does not remove microscopic particles which may cause the wine to appear cloudy.
Fining: Fining agent (examples, gelatin, egg white, bentonite clay) added to the wine to bind with the undesired particles. These fall to the bottom and are removed.
Filtering: Straining of the wine though a barrier with very fine openings.
Centrifuge: Use of gravity - via laboratory equipment - that separates the solid particles from the rest of the wine.

Question 14

Describe Malolactic Fermentation

Answer 14

A secondary fermentation (which isn’t really a fermentation) where a particular strain of lactic acid bacteria decomposes the sharp malic acid in the wine, converting it to lactic acid.

Question 15

Why might sulfur be added post fermentation?

Answer 15

To decrease the chances of microbial spoilage or browning in the finished wine.

Question 16

What are “wine diamonds”?

Answer 16

Tartrate crystals.

These appear when white wine is kept at cold temperatures, which is why some vintners may choose to shill the wine to around 25 degrees F for 1-3 weeks, allowing the tartrates to form and be removed before bottling.

Question 17

What are tartrate crystals sometimes referred to?

Answer 17

Wine Diamonds.

Question 18

True or False:

White wine ferments without skins in the must.

Red wine ferments with skins in the must.

Answer 18

True.

Skins are needed in the must of red wine so the phenolics can be extracted.

Question 19

What is cap management?

Answer 19

The “cap” of a fermenting wine is made up of the grape solids (skins, stems, etc) that are pushed to the top of the liquid from the carbon dioxide produced during the fermentation.

This cap that forms needs to be reintegrated with the fermenting liquid to enable the continual extraction of the phenolics. It’s also needed to prevent an explosion of the cap into the air which could occur if carbon dioxide gets trapped underneath the cap.

There are four common methods of cap management:

Punching Down
Pumping Over
Rack and Return
Rotofermentation

Question 20

What is a typical temperature range for red wine fermentation?

Answer 20

60-70: Lighter Reds
85-95: Bolder Reds

Question 21

What does “extended maceration” describe?

Answer 21

Extended maceration is when the skins are left in the wine after the fermentation has stopped - may be several days to several weeks. This is done for more extensive extraction of the phenolics.

Question 22

How does allowing a wine to undergo malolactic fermentation support its future stability?

Answer 22

MLF reduces the amount of malic acid available for bacteria to attack.

Question 23

How and when does malolactic fermentation occur in red wine?

Answer 23

May be spontaneous or initiated via the addition of lactic-acid producing bacteria.

May occur at any point from the start of the fermentation to the transfer of the wine into barrels for aging.

Question 24

Why are Fining and Filtering not as commonly used for clarification with red wines as they are with white wines?

Answer 24

Fining and filtering may have the undesirable effect of removing some of the phenolics. Therefore racking (one or more) would be a more common technique used to clarify the wine.

Question 25

How does aging in oak barrels help to “soften” a red wine?

Answer 25

Aging in oak barrels allows a slow infusion of oxygen into the wine. This helps the tannin molecules combine with each other - a process called polymerization. The longer polymerized tannins feels softer and richer than the shorter tannins found in grapes.

Question 26

Approximately how many years of use does it take for an oak barrel to reach a neutral state?

Answer 26

Four years

Question 27

True or False.

Carbonic maceration requires neither yeast nor bacteria.

Answer 27

True

With carbonic maceration, grapes are blanketed with carbon dioxide, the enzymes within the grapes themselves will begin to break down sugars and convert sugars to alcohol within the berries.

Note that its rare for a full fermentation to occur through carbonic maceration. It is more common for carbonic maceration to be used in the initial phases of wine making after which the remaining sugars are converted via a normal alcoholic fermentation.

Question 28

What are the three most common ways of creating a rose wine?

Answer 28

1. Minimal contact with skins (red grapes)
2. Co fermentation of white grapes and red grapes
3. Blending a small amount of finished red wine with a finished white wine.

Question 29

Described the Saignee method of wine production.

Answer 29

Red grapes are crushed and vatted, juice is bled off to make a rose wine. Remaining juice remains in contact with the skins and is using to make a red wine.

The end result is a rose wine and a concentrated red wine from the same batch of grapes.

Question 30

Describe the ‘direct press’ method of wine making. What is it used for primarily?

Answer 30

The direct press method is using primarily to make pale rose wines, such as those produced in Provence.

In this method the grapes are crushed and pressed immediately after harvest, the pale pink juice from the press is fermented to a rose wine.

In France, these wine are often referred to as vin grits.

Question 31

What does Weissherbst refer to?

Answer 31

German term for Rose.

(Rosado - Spanish, Rosato- Italian, Rose - French)

Question 32

List four common paths to the creation of a sweet wine.

Answer 32

Botrytis: Botrytis Cinerea / Noble Rot - fungus that causes water to evaporate from the berries, concentrating the sugars in the grapes.

Late harvest: Berries continue to gain sugars as long as there are green leaves on the vine. They will also lose water during this time, further concentrating the sugars. Note that they also lose acidity.

Dried Grapes: Grapes are dried prior to fermentation, concentrating the sugars. May result in a high alcohol, dry wine. Or a sweet wine.

Freezing: Frozen grapes that are high in sugar (due to latest harvesting times) are pressed immediately, resulting in high sugar juice. This is where “ice wine” comes from. Note that you can also freeze late harvest grapes with similar results, a process called cryoextraction.

Question 33

Which two grapes are known as being well suited for botrytis?

Answer 33

Semillon and Chenin Blanc. Due to their thin skins.

Question 34

Which two grapes are cited as being ideal candidates for late harvest?

Answer 34

Riesling and Chenin Blanc, due to their naturally high acidity.

Question 35

How are orange wines made?

Answer 35

Juice from white grapes undergo a longer maceration period where they extract tannin, color, and achieve some level of oxidative resistance. This results in the wine developing a coppery/orange hue.