How Wine is Made (Cellar)

Question 1

What’s the difference between crushing and pressing in winemaking?

Hint: crushing is not developing feelings for an attractive cellar worker.

Answer 1

Crushing is the gentle application of pressure to break the grape skins and releases the juice, making it available for fermentation.

Pressing is the separation of the juice or wine from the skins and seeds.

To further explain, crushing is done at the start of the winemaking process for red wines and rosés. This liberates the juice, while retaining the skins and seeds in the mix, which imparts color and tannin to the wine.

Pressing, which is the separation of the juice/wine from the skins/seeds, is done after fermentation for red wines, when they’ve extracted sufficient color and tannin from the skins/seeds.

For white wines, however, the grapes are pressed immediately before fermentation so that the only thing fermenting is the pure juice, without the influence of seeds and skins.

Question 2

What happens when grape juice undergoes alcoholic fermentation?

Answer 2

The sugar in the grape juice is consumed by yeasts, which produce alcohol and carbon dioxide as by-products.

In winemaking there are two phases of fermentation, the first being alcoholic fermentation, which is done to transform the grape juice into, essentially, wine.

The second is malolactic fermentation, which is done for almost all red wines and some white wines (like Chardonnay) to give them a fuller body and smoother mouth-feel.

Question 3

What microorganism carries out alcoholic fermentation in wine?

Answer 3

Yeasts

Yeasts are single-celled microorganisms that belong to the fungus kingdom. They occur naturally on most living surfaces but winemakers do use a specific species of yeast—Saccharomyces cerevisiae—in order to control the rate of fermentation, as well as the resultant flavors of the wine.

Question 4

When does alcoholic fermentation stop?

Answer 4

When yeasts have eaten all the sugar.

The result is a dry wine; “dry” meaning there’s no residual sugar remaining. Essentially, the yeasts have run out of fuel!

Question 5

What is the typical range of alcohol in a dry wine?

Answer 5

11.5% - 16% abv

Question 6

What does ABV stand for?

Answer 6

Alcohol By Volume

ABV is the measure of how much alcohol is in a wine, expressed as a percentage.

Question 7

What is the difference between storage and maturation?

Answer 7

• Storage is for wines that are made for early consumption.
• Maturation is when wines are stored longer than a few months, in order to develop flavor and body prior to release.

With storage, once alcoholic fermentation is complete, the new wine—usually white wines and rosés—are left to settle for a short while (usually just a few months) prior to bottling.

Maturation most often happens in barrels but can also be in the bottle itself, like most red wines, some full-bodied white wines, and traditional method sparklings wines (Champagne).

Question 8

List the five main steps taken to craft white wines.

Answer 8

1. Harvesting
2. Pressing
3. Alcoholic fermentation
4. Maturation
5. Packaging (bottling)

Read our guide for an in-depth blow-by-blow account of [how wine is made (at home)!] (https://www.brainscape.com/academy/how-make-wine-home/)

Question 9

When are grapes for white wines crushed and pressed?

Answer 9

Before fermentation

Ideally, shortly after they’re harvested and brought to the winery.

Question 10

White wines are typically fermented at 12°C - 22°C (54°F - 72°F). What effect will a lower fermentation temperature have on the wine?

Answer 10

Lower fermentation temperatures bring about fruitier aromas.

Rosé wines are typically fermented at similar temperatures to white wines.

Watch: ‘Should you drink rosé in winter?’

Question 11

What is grape must?

Answer 11

The freshly crushed grape juice that may (or may not) contain the skins, seeds, and stems of the fruit

In other words, it’s the “stuff” that’s fermented to make the wine!

Question 12

What can winemakers add to the grape must to tweak the flavors and balance of the resultant wine?

Answer 12

1. Sugar to increase alcohol
2. Acid to balance sweetness

Question 13

What is the most common must adjustment made to white grapes from warm/hot climates?

Answer 13

Acidification

Grapes grown in warm climates have higher accumulated sugars and lower natural acidity. The fruity, sweet elements of the resultant wine would be quite cloying and overpowering, and so winemakers add acid to the grape must to turn up the tartness to restore the wine’s balance.

Question 14

How does adding sugar to the must before or during fermentation change the final wine?

Answer 14

Adding sugar before or during fermentation increases the alcohol level in a wine.

More sugar gives the yeasts more food to eat and so they produce more alcohol as a by-product.

Fun fact: beet and cane sugar are most commonly used.

Question 15

What is meant by the term residual sugar in winemaking?

Answer 15

Natural sugar that remains in a wine after fermentation.

Wine grapes contain the natural sugars fructose and glucose.

A wine with little to no residual sugar will taste dry, while a wine with some residual sugar can be off-dry to sweet, depending on the amount of sugar remaining after fermentation.

Question 16

What does “off-dry” mean?

Answer 16

When a wine’s residual sugar is just-perceptible.

Leaving a little residual sugar after fermentation creates wines that are more fruit-forward and, be warned, a little too easy to drink, especially on a hot day!

Wines that are commonly made in an off-dry style are riesling, gewürztraminer, muscat, and torrontés.

Question 17

What are 3 ways winemakers can ensure that the yeast doesn’t consume all the sugar?

… and, in doing so, ensure the resultant wine is off-dry or sweet in style?

Answer 17

1. Use grape juice that has such concentrated sugars—such as frozen, extra-ripe, or Botrytis-affected grapes that the yeasts can’t eat it all (e.g. Hungarian Aszú)
2. Remove the yeast cells from the fermenting juice, usually via fine filtration (e.g. White Zinfandel)
3. Kill the yeast cells by adding alcohol in the fortification process (e.g. Port)

Question 18

What are 3 ways a winemaker can sweeten up a dry wine?

Answer 18

1. Add unfermented grape juice
2. Add concentrated grape juice
3. Blend the dry wine with a sweet wine

Why would a winemaker want to sweeten up a dry wine?

Because boo-boos happen! One of the mistakes an inexperienced winemaker can make—or even an experienced one—is making a wine that is simply too dry and astringent. “Back sweetening” is a simple way to transform a wine that turns your mouth inside out into something more palatable.

And if it saves a batch of wine from being wasted, why not?

Question 19

What 3 kinds of vessels are commonly used to ferment white wines?

Answer 19

• Oak barrels
• Inert vessels
  
  • Stainless steel
  • Concrete

Inert vessels don’t in any way interact with the wine itself, imparting no flavor to it.

Oak barrels, on the other hand, are used to impart lovely caramel, clove, baking spice, and butterscotch flavors to wines like Chardonnay.

Question 20

What are 2 advantages of fermenting white wines in stainless steel?

Answer 20

1. Stainless steel is inert and doesn’t add flavor to wine, which therefore maintains the varietal’s character;
2. It can also be made airtight, preventing oxygen from coming into contact with the wine and changing its flavors.

Aromatic white wines like Sauvignon Blanc, Riesling, and Pinot Grigio (Gris) are most often made in steel tanks because oak might otherwise overpower lovely fruity and floral aromas.

Question 21

What are 2 advantages of fermenting wine in oak barrels?

Answer 21

1. Barrels add woody and toasty flavors straight into the wine;
2. Barrels encourage flavor development due to the presence of oxygen.

As airtight as a barrel can seem, the wood itself allows oxygen to very slowly percolate into the wine, causing oxidation and the development of flavor. Too much oxidation, however, and you’ll be sitting with a barrel full of white or red wine vinegar!

Question 22

When aging a white wine in new oak, what flavors will develop?

try to list 6!

Answer 22

• Vanilla
• Toast
• Smoke
• Coconut
• Baking spice (clove, dill, nutmeg, anise)
• Sweet spice (molasses, brown sugar, butterscotch)

Question 23

What 3 factors determine how much flavor an oak barrel imparts to a wine?

Answer 23

1. How the barrel was made: what was its level of toasting?
2. Age of barrel: if it’s new, it’ll impart more wood flavor than a used one
3. Size of barrel: the larger the barrel, the greater the volume of the wine and, therefore, the lower the concentration of “oakiness”

If the label describes the wine as having been aged in new oak barrels, then those “oaky flavors” will be much more powerful, as is typical of, for example, a voluptuous Napa Valley Chardonnay.

If, on the other hand, a wine is aged in second- or third-fill barrels, the wood will be more subtle, resulting in more elegant white wines, where the other, more crisp flavors can stand out.

Question 24

Why are the effects of oak more pronounced in small barrels than in large barrels?

Answer 24

In smaller barrels, more of the wine’s surface area comes into direct contact with the wood.

Question 25

What do you call barrels that have never been used before?

Answer 25

new oak

Question 26

What do you call barrels that have have been used 3 times or more?

Answer 26

old or neutral oak

Question 27

What less-costly methods are sometimes used to add desirable oak flavors to value-priced white wines?

Answer 27

Oak staves or oak chips are added to the wine during aging

This cheaper method doesn’t impart or integrate the oak flavors as effectively into the final wine as oak barrels do, which is why it’s never used to make premium white wines.

Question 28

What are lees?

Answer 28

Lees are dead yeast cells that fall to the bottom of a vessel after fermentation.

The lees need to be filtered out before bottling.

Question 29

Why would a winemaker stir up the lees or keep a wine “on its lees” during maturation?

Answer 29

Lees add:

• A creamy, rounded texture and richer body, and
• Bread-like flavors (freshly baked bread, brioche) to the wine

Allowing a wine to mature “on the lees” is an important step in the traditional Méthode Champenoise, which is why many Champagnes (and bubbly wines made in this style) deliver delicious, rich aromas of brioche on the nose.

Question 30

Why don’t aromatic white grape varieties typically go through lees aging or lees stirring?

like Sauvignon Blanc or Riesling

Answer 30

Because the bread-like flavors from the lees would impede the purity of fruit flavors desired in aromatic varieties.

Question 31

What is malolactic conversion?

Answer 31

The transformation of tarter malic acid (the same acid in an under-ripe apple) into softer lactic acid (the same acid in yogurt).

Malolactic conversion is introduced into the winemaking process of some white wines and all still red wines in order to achieve a fuller, rounder mouthfeel.

Question 32

What causes/carries out malolactic conversion?

Answer 32

Bacteria

Malolactic conversion is oftentimes referred to as “malolactic fermentation” but since yeast cells aren’t used, it strictly speaking isn’t a fermentation.

Question 33

When would a winemaker begin malolactic conversion?

Answer 33

After alcoholic fermentation is complete.

Question 34

What flavors do malolactic conversion impart on wine?

Answer 34

Buttery flavors, including anything from freshly churned butter to movie theater popcorn butter.

Malolactic conversion also has a marked effect on “mouth feel” and the texture of a wine, making it richer and creamier.

Question 35

Why would a winemaker block malolactic conversion on an aromatic grape varietal?

Answer 35

Because the buttery aromas and flavors would obstruct the pure fruit aromatics and flavors of the aromatic grape varietals.

I.e. for the same reason aromatic varietal wines aren’t typically left to mature on the lees.

Question 36

What 2 white grape varieties are winemakers most likely to use malolactic conversion with?

Answer 36

Chardonnay and Viognier

Question 37

What 2 white grape varieties are winemakers least likely to use malolactic conversion with?

Answer 37

Riesling and Gewürztraminer

Question 38

Do white wines get lighter or darker in color as they age?

Answer 38

Darker in color

White wines turn gold and amber as they age.

Wine is made from grapes, which are a fruit; and most fruits will turn brown if you leave them exposed to oxygen for too long (e.g. leaving sliced apple or avocado uncovered on your kitchen counter).

Question 39

What sorts of flavors can a white wine develop in the barrel when exposed to oxygen?

Answer 39

• Caramel
• Dried fruit
• Nuts (almonds, hazelnuts, walnuts)

Question 40

What desirable characteristics does white wine ideally have to allow it to mature well in the bottle?

Answer 40

• Higher acidity levels
• High levels of residual sugar
• Concentration of flavors that can withstand and evolve with time in the bottle

Question 41

What are 2 reasons a winemaker would add two or more different wines together to create a blend?

Answer 41

• Maintain consistency and style of a wine
• Create complexity

Every grape varietal has its own characteristics, whether it’s power and heft (Cabernet Sauvignon) or fruity aromatics (Merlot). Adding the two together in the right combination creates a wine that is elevated because it will have the benefits of BOTH varietals, creating complexity where before there was only a one or two-dimensional wine.

Understanding this, winemakers can—in a sort of alchemy—blend different wines together to achieve a consistent flavor profile for a particular wine label that strives to be the same year after year, even though every vintage’s weather conditions may have yielded grapes with different characteristics.

Question 42

List the six main steps taken to craft red wines.

Answer 42

1. Crushing
2. Alcoholic fermentation
3. Draining
4. Pressing
5. Storage or maturation
6. Packaging

Question 43

What is the cap?

Answer 43

The cap is a thick layer of grape skins that rises to the surface during fermentation and floats on top of the fermenting must.

Question 44

Why is the cap mixed with the fermenting grape juice?

Answer 44

To ensure that all that lovely, rich color and tannins are being extracted from the grapes.

This mixing is done in two ways: through punching down—which involves physically breaking up this cap of skins and solids with an implement that pushes the grape skins down, allowing them to mix with the fermenting juice beneath—and pumping over, also known as remontage—the process of pumping juice up from the bottom of the tank and splashing it over the top of the fermenting must.

Question 45

What is the name of the process when the cap is submerged and stirred back into the fermenting must, agitating the grape skins so as to extract as much color and tannin from them as possible?

Answer 45

Punching down

Punch down tools have holes in the bottom of them so that the grapes and air can flow through, making punching down easier.

Question 46

What is the name of the process when a hose sucks fermenting juice from the bottom of a fermentation vessel and sprays it back out over the top of the cap?

Answer 46

Pumping over

Compared with punching down, pumping over is gentler way of extracting color and tannin, which may be the preferred method for crafting lighter-style red wines and rosés.

Question 47

What are the 2 most common ways of making rosé?

Answer 47

1. Short maceration
2. Blending

Short maceration is where the red skins are in contact with the juice for only a few hours and so only the desired amount of color and tannin is extracted. The resultant pink juice is then drained from the skins and fermented at a temperature usually used for making white wine.

Blending is where a red and white wine are combined to produce a rosé. This technique is permitted in most countries except for parts of the European Union.

Question 48

True or false:

When making rosé via short maceration, fermentation starts off like making a red wine but then finishes like making a white wine.

Answer 48

TRUE

Red wines are made by fermenting grape juice with the skins. With (short maceration) rosé however, this skin contact is only permitted for a short amount of time so as to extract a little bit of the color and tannin.

Once the desired color is achieved, the winemaker will remove the skins and continue using white wine-making techniques to craft the rosé.

Question 49

Do rosé wines undergo malolactic conversion?

Answer 49

No, malolactic conversion is avoided for most rosé production.

Why? Well, one of the defining, desirable traits of rosé is its crisp, fresh acidity! Malolactic conversion introduces a buttery, creamy texture that doesn’t pair well with a hot day the way we want our rosés to #roséallday!

Question 50

When does the pressing process occur for white wines? And when does it occur for red wines?

Answer 50

For white wines, pressing occurs before fermentation; and for red wines, after fermentation.

Pressing involves straining the juice of all solids and then squeezing the remaining skins and seeds (the pommace) to get the residual wine out. The more thoroughly they are pressed, the richer the color of the resultant wine and the heavier the tannins.

Question 51

If the grapes were lower in sugar at harvest, will the resultant wine be higher or lower in alcohol?

Answer 51

Lower

Remember, yeast cells munch on sugar and produce alcohol as a by-product. If there isn’t a lot of sugar for them to eat, they won’t produce a lot of alcohol.

Question 52

If the grapes were higher in sugar at harvest, will the resultant wine be lower or higher in alcohol?

Answer 52

Higher

More sugar means more food for yeast to eat, which produces more alcohol as a by-product.

Question 53

What are the 3 major differences between the way red wines and white wines are made?

Answer 53

Red wines:
* Are pressed after fermentation;
* Spend an extended period of time in contact with their skins before and during fermentation; and
* Always undergo malolactic conversion.

White wines:
* Are pressed before fermentation
* Don’t undergo a lot of skin contact; and
* Typically don’t undergo malolactic conversion, although many winemakers use it to craft fuller-bodied whites like Chardonnay and Viognier.

Question 54

Which wine (red or white) is usually fermented at warmer temperatures?

Answer 54

Red wine

The heat of alcoholic fermentation helps to extract color and tannins from the skins.

Question 55

Why are red wines fermented at higher temperatures than white wines?

Answer 55

The higher temperatures promote the extraction of color, flavor, and tannin which are the hallmarks of red wines.

Question 56

For which red wines is malolactic conversion used in the production process?

Answer 56

For ALL red wines.

Malolactic conversion is standard practice in the production of red wine, rather than merely being a stylistic choice. This is because it enhances the body and flavor persistence of the wine, while the creamier, softer textures balance out the reds’ naturally heavier tannins.