D1 Maturation 2: Packaging, Transportation, Post-Bottle Maturation

Question 1

Besides hygiene, the most important consideration when bottling wine in its final container is ____ ____.

Why?

Answer 1

Oxygen management

The amount of oxygen in the final container determines the shelf life and development of the wine.

• too much oxygen = premature browning and oxidized notes;
• too little oxygen = reductive characters.

Question 2

What does OTR stand for?

Answer 2

Oxygen transmission rate

Question 3

The total oxygen in a wine is a combination of these four things:

Answer 3

1. Amount of dissolved oxygen in the wine;
2. Oxygen in the head space (usually the greatest contributor);
3. Amount of oxygen in the closure;
4. Oxygen transmission rate (OTR) of the cork or closure.

Numbers 1 and 2 – the amount of dissolved oxygen in the wine and the oxygen trapped in the headspace – together have the most significant impact on the development of the wine in the bottle.

Question 4

What are today’s packaging options for wine, and which is the most preferred option?

Answer 4

1. Glass;
2. Plastic / PET (polyethylene terephthalate);
3. Bag-in-box;
4. Tetra Pak / Brick;
5. Pouch;
6. Can.

Question 5

What are the advantages of glass packaging?

Answer 5

1. Inert material that transfers no taint;
2. Bottles can be delivered to wineries in a near-sterile condition, having been shrink-wrapped while still hot;
3. Inexpensive to manufacture and there is a variety of colors;
4. Recyclable;
5. Best option for aging wine because it is impermeable to oxygen.

Question 6

What are the disadvantages of glass packaging?

Answer 6

1. High carbon footprint due to the heat needed to manufacture it;
2. Heavy to transport, which also contributes to its carbon footprint especially if it is transported far from its final market;
3. Somewhat fragile;
4. Once a bottle of wine has been opened, it is subject to rapid oxidation;
5. Clear bottles susceptible to light strike.

Question 7

Which type of wine is most suitable to be packaged in PET (polyethylene terephthalate)?

Answer 7

• Wines with a limited shelf life;
• Wines for quick consumption and in informal settings (outdoor eating, travel);
• Wine designated for airplanes where breakage is a hazard.

Question 8

What is the bag in the Bag-in-box made of?

Answer 8

2 possibilities:

1. Very thin aluminium foil (which protects the wine from oxygen) covered on both sides by an acceptable plastic;
2. Plastic that gives some protection from oxygen and is resistant to cracking.

Question 9

What are the advantages of packaging wine in Bag-in-box?

Answer 9

1. Wine on tap (pour any serving size);
2. Good protection from oxygen because the bag collapses inside the box;
3. Range of sizes (1.5–20 liters), can be used for home and commercial use;
4. Easy to store (stackable);
5. Low environmental impact (light to transport, recyclable).

Question 10

What does wine that’s been packaged in Bag-in-box have to have (vis-à-vis wine packaged in a glass bottle)?

Answer 10

• Slightly higher SO₂ level to counter oxidation;
• Low dissolved oxygen level;
• No head space;
• Low carbon dioxide to avoid the bag from bulging or bursting.

Question 11

Where does most oxygen ingress occur in Bag-in-box?

Answer 11

The tap

Question 12

What is the average shelf life range for wines packaged in Bag-in-box?

Answer 12

6-9 months, depending on how the wine was made

Question 13

What material is the Tetra Pak, or ‘Brick’, made of?

Answer 13

Paper card with plastic layers and an aluminium foil layer that prohibits oxygen and light from affecting the wine

Question 14

In what kinds of markets do Tetra Paks / Bricks do well?

Answer 14

Ones where lower price points drive the market

Question 15

What are the advantages of packaging wine in cans?

Answer 15

1. Light in weight;
2. Easy to open;
3. Impermeable to oxygen;
4. Recyclable.

Question 16

Aluminium cans have to be lined with ____ to avoid the material being attacked by the acidity of the wine.

Answer 16

Plastic

Question 17

The types of wines being packaged in cans are:

1. Inexpensive and mid-priced
2. Mid-priced and high-priced
3. High-priced exclusively

Answer 17

1. Inexpensive and mid-priced wines

Question 18

What are the five most common closures for wine bottles?

Answer 18

1. Natural cork;
2. Technical corks;
3. Synthetic closures;
4. Screwcap;
5. Glass stoppers / Vinolok.

Question 19

What are the advantages of using natural cork as a closure?

Answer 19

1. Light;
2. Flexible;
3. Inert;
4. Comes from a renewable, natural resource;
5. Has a positive image in the eyes of consumers – opening a bottle with a corkscrew is seen as part of the enjoyment and ritual of drinking wine.

Question 20

Shorter, lower-grade corks are cheaper and are usually used for what kind of wine?

Answer 20

Inexpensive wines intended for short term consumption

Question 21

Better quality, longer corks are typically used for what kind of wines?

Answer 21

Higher-priced wines that can be aged in bottle

Question 22

What are the two major issues with natural cork?

Answer 22

1. Corks can transmit TCA (2,4,6-trichloroanisole) to the wine (on average 3–5% of bottles closed with cork suffer from TCA);
2. Natural corks have variable rates of oxygen ingress.

Question 23

In an effort to reduce the incidence of cork taint, what are some of the measures the industry has taken?

Answer 23

1. Cleaning corks with steam extraction (Amorim);
2. Creating a technical cork made from recomposed cork particles that have been cleaned and reconstituted with plastic; it looks and behaves like natural cork (Diam);
3. Stricter quality control during cork production, e.g. using high-cost high-tech solutions to check for the presence of TCA;
4. Putting an impermeable membrane between the cork and the wine that gives a wrinkled appearance on the end of the cork and prevents any aromas reaching the wine.

Question 24

What are three technical corks available on the market today?

Answer 24

1. Agglomerated cork
   
   • cork granules are glued together;
   • should only be used on inexpensive wines intended to be drunk quickly after purchase;
2. One-plus-one cork
   
   • the central section is inexpensive agglomerate and both ends are finished with a disc of natural cork;
3. Diam cork
   
   • recomposed cork particles that have been cleaned and reconstituted with plastic, and come with varying oxygen-ingress rates.

Question 25

What are synthetic closures made from?

Answer 25

Food-grade plastic with a silicone coating

Question 26

Name two hazards that come with using synthetic closures.

Answer 26

1. Limited protection from oxygen ingress;
2. Flavor scalping (the plastic absorbs some of the flavor molecules in the wine).

Question 27

The seal in screwcaps that protects wine from oxygen can be made of two materials.

What are those materials, and how permeable/impermeable are they?

Answer 27

1. Tin, which is impermeable to oxygen;
2. Saran, which is a form of plastic with low permeability to oxygen.

Question 28

How do winemakers avoid their wine developing reductiveness after bottling their wine under screwcap?

Answer 28

They use slightly lower levels of SO₂

Question 29

Glass stoppers are really only suitable for:

• Inexpensive wines
• Mid-priced wines
• Premium and super-premium wines

Answer 29

Premium and super-premium wines

Wines can age under glass stoppers a similar amount of time as under natural cork, and they are as expensive as top-quality cork.

Question 30

Most wines that are based on fresh, fruity flavors are best consumed:

• within a year of bottling as maturing results in a loss of primary fruit flavors
• after several years because they’re not at their best immediately after bottling

Answer 30

Within a year of bottling as maturing results in a loss of primary fruit flavors

Question 31

Describe the ideal environment for bottle maturation.

Answer 31

The wine should rest undisturbed in a cool dark place with a constant temperature, around 10–15°C / 50–59°F. There should also be constant humidity.

If sealed with a cork, the bottles should rest lying on their sides, so the cork stays moist and keeps the bottle sealed (if the cork dries out, the wine will oxidize).

Question 32

What are the three hygiene procedures to follow in a winery?

Answer 32

1. Cleaning
   
   • this removes surface dirt
2. Sanitation
   
   • this reduces undesirable organisms to an acceptable level;
   • made of water + detergent, another sanitising agent and/or steam;
   • this uses ~10 liters of water for every liter of wine produced;
3. Sterilization
   
   • this eliminates unwanted organisms;
   • sterilization is done with high strength alcohol or with steam.

Question 33

Briefly explain why HACCP (Hazard Analysis of Critical Control Points) is a common approach used in wineries to assess quality assurance.

Answer 33

It’s a process that examines all the potential hazards and everything that could go wrong in the winery so the winery can prevent and correct any issues before they happen.

Question 34

Why would a wine company seek to have their quality standards to be externally audited by a third party against the standards of the ISO (International Organization for Standardization)?

Answer 34

To give confidence to all the parties down the supply chain: the wholesaler, the retailers who will sell the wine, and the end consumer.

Question 35

The EU and many other markets require wines to be assigned lot numbers and to have those lot numbers printed on the wine’s label.

What does having a lot number enable the winery to do in the event of complaints or problems?

Answer 35

To trace back:

• Where the grapes came from;
• What additives were used;
• What processes the wine went through;
• How the wine was transported.

Question 36

What are the two main types of containers used for shipping bulk wine?

Answer 36

1. Flexitank – a single-use, recyclable polyethylene bag that fits into a standard container (more common);
2. ISO tank – a stainless steel vessel that can be reused many times that is built to the ISO standard; it may have additional insulation.

A third and not-so-common container type is known as a reefer, which is an insulated tank with temperature control, but they are expensive.

Question 37

What is the advantage of shipping wine in bottle as a complete product?

Answer 37

Everything is controlled by the producer: the wine, the bottling, the labelling and any external packaging.

Question 38

What are the disadvantages of shipping wine in bottle as a complete product?

Answer 38

1. Less wine can be shipped in one container, so the cost to ship is higher;
2. The financial and environmental cost of shipping the weight of glass (as well as the wine);
3. Potential damage/spoilage to the wine due to sometimes high and fluctuating temperatures in transit;
4. Potential damage of labels and packaging in transport;
5. The shorter shelf life of inexpensive wine because it is bottled earlier than if it were bottled in or close to the final market.

Question 39

What are the advantages of shipping wine in bulk?

Answer 39

1. Environmentally friendly and cheaper (containers hold 2-2.5x as much wine as filled bottles, reducing the wine’s carbon footprint);
2. The greater thermal inertia of a whole container filled with wine, so there is less fluctuation of temperature (reducing the risk of oxidation);
3. Strict quality control: chemical analysis can be performed at the filling and emptying of the container;
4. The wine can be adjusted at the point of bottling;
5. The shelf life of a wine can be extended, which is most relevant for bag-in-box and its relatively short shelf life.

Question 40

What are the disadvantages of shipping wine in bulk?

Answer 40

1. Loss of the direct relationship with the producer;
2. Business and employment opportunities transfer from the producer’s country to that of the final market.

Question 41

Why is the majority of white wines made with no or minimal skin contact?

Answer 41

Because the principal aroma and flavor compounds of white grapes that are desirable in white wines are in the pulp

Skin contact in white wines isn’t required for aroma and flavor extraction.

Question 42

What are two negative effects if a white wine sees excessive skin contact?

Answer 42

The wine can:

• Taste bitter
• Feel coarse on the palate.

Question 43

Give five reasons why a winemaker would use no skin contact or minimal skin contact on their white wines.

Answer 43

1. If the wine is meant to express delicate, fruity flavors;
2. If the winemaker wants a smooth mouthfeel;
3. If the winemaker wants a light color on the wine;
4. If the fruit was picked under-ripe;
5. If the wine is inexpensive and meant to be drunk very young.

Question 44

What are the two key factors that can influence extraction during skin contact?

Answer 44

1. Time;
   
   • longer time on skins = greater extraction of flavor + tannins
2. Temperature.

Question 45

How does a cooler temperature affect extraction during skin contact?

Answer 45

Chilled juice during skin contact (15°C /59°F or below) reduces the rate of extraction of flavors and tannins.

It also:

• allows more control;
• reduces the rate of oxidation and microbial spoilage, including likelihood of spontaneous fermentation.

The wine is usually pressed to separate the skins and juice before fermentation begins.

Question 46

What are some white grape varieties on which skin contact is most effective?

Answer 46

Aromatic grape varieties like Riesling, Gewurztraminer, Viognier, Muscat and Sauvignon Blanc

• they have many aroma compounds that can be extracted from the skins;
• aromatic varieties are not often matured in oak, so skin contact is also a way of enhancing texture.

Question 47

Describe the profile of an ‘orange wine.’

Answer 47

• Fermented on their skins, usually without temperature control or sulfur additions;
• Notable levels of tannins;
• Main flavors and characteristics are tertiary, e.g. nuts, hay, and dried fruit, which emerge from aromatic and phenolic compounds extracted from the skins;
• Typically dry (though not always).

Question 48

What are the advantages of using whole-bunch pressing for white grapes?

Answer 48

1. Reduces the chance of oxidation before and during pressing;
   
   • more so if an inert gas (e.g. nitrogen) is used in the press;
2. Very gentle way of pressing grapes;
3. Yields juice that is low in solids, tannins and color;
4. Stems provide channels for the juice to drain.

Question 49

What are the disadvantages of using whole-bunch pressing for white grapes?

Answer 49

1. Restricted only to hand-harvested grapes;
2. Whole bunches take up a lot of room in the press;
   
   • fewer grapes can be loaded for each press cycle;
3. Only really suited for smaller batches of premium wines;
4. Inefficient for grapes that need to be processed quickly and efficiently.

Question 50

What is the difference between “free run” juice and “press” juice?

Answer 50

Free run = juice from destemmed grapes that is drained off as soon as the grapes are crushed. It is lowest in solids, tannins, and color, and it’s higher in acidity (low pH). Good for lighter bodied style of wine.

Press juice = juice from the grapes being pressed. The first part of the first pressing is somewhat similar to free run in that solids, tannins, and color are low, but ultimately it has lower sugar and acidity than free run. As pressure is sustained and more is applied for each press fraction, the less like free run the juice becomes. Press juice makes wines with fuller body compared to wines made from free run.

Question 51

What is the hyperoxidation technique, and what does it do?

Answer 51

It is a technique in which the winemaker deliberately exposes the must to large quantities of oxygen before fermentation.

It targets the compounds in the must that oxidize most readily, turning these compounds in the must brown.

Question 52

When employing the hyperoxidation technique, how do winemakers remove the compounds that have turned brown?

Answer 52

These compounds naturally precipitate out of the wine during fermentation, which return the wine back to its normal color.

Question 53

In what other ways does hyperoxidation help winemakers when they make white wines?

Is hyperoxidation typically better suited for neutral or aromatic grape varieties?

Answer 53

1. Can remove bitter compounds from unripe grape skins, seeds and stems;
2. Can destroy some of the most volatile aroma compounds found in the must;
   
   • typically better suited to less aromatic grape varieties, e.g. Chardonnay.

Question 54

At what points can clarification occur in winemaking?

Answer 54

• Between pressing and fermentation;
• After fermentation.

Question 55

What is the aim of clarification?

Answer 55

To reduce the amount of suspended solids in the must

Question 56

Winemakers typically aim for the proportion of solids in the must to be somewhere between ___–___%.

Answer 56

0.5–2%

Question 57

What does a higher proportion of solids in a white wine must lend to the finished product?

Wine at what price point is best suited for using this technique?

Answer 57

• Texture;
• Greater range and complexity of aromas from fermentation.

Best suited for small-volume, premium wines.

Question 58

What is a risk of having too many solids in white wine must during fermentation?

Answer 58

Off-flavors developing from reactions between compounds within the solids

• at lower levels, they can smell like reductive sulfur compounds;
• at higher levels, can smell like rotten egg.

Question 59

1. Why is it good to have some solids in your must?
2. What is a risk of having low to no solids in your must?

Answer 59

1. Solids provide nutrients for yeast;
2. Low to no solids can lead to stuck fermentations; these musts also need careful management, and yeast nutrients may need to be added.

Question 60

What are the four options winemakers have to clarify must?

Answer 60

1. Sedimentation (simplest form);
2. Flotation;
3. Centrifugation;
4. Clarifying agents.

Question 61

Sedimentation can be used to clarify grape must.

Describe the process of sedimentation.

Answer 61

• The must is chilled to 4°C / 39°F to reduce oxidation and microbial spoilage, and to avoid spontaneous fermentation;
• Suspended solids in the must are left to fall over time with gravity.

Question 62

What does the rate of sedimentation depend on?

How long does sedimentation typically take?

Answer 62

Size and shape of the vessel

• Large, tall vessels = longer sedimentation;
• Smaller, shorter vessels = shorter sedimentation.

Sedimentation takes 12-24 hours.

Question 63

What happens to the must and solids after sedimentation?

Answer 63

• The must is racked to a fermentation vessel;
• The solids are usually filtered by cross flow or depth filters to extract extra juice.

Question 64

How does flotation work?

Answer 64

An inert gas (like nitrogen) is bubbled up through the must and as it rises it brings with it solid particles; those particles are then skimmed off.

If oxygen is used as the gas, this is a method of hyperoxidation.

Question 65

Compared to sedimentation, flotation:

• speeds up the rate of clarification
• slows down the rate of clarification
• doesn’t affect the rate of clarification

Answer 65

Speeds up the rate of clarification

Advantage: flotation is fast and effective!

Question 66

What needs to be added to the must in order for flotation to work?

Answer 66

Fining agents, which help bind the particles together

Note: wine does not have to be chilled in order for flotation to be used.

Question 67

Flotation can be used:

• on both must or wine
• only on must
• only on wine

Answer 67

Only on must

Question 68

Flotation can be used:

• Only as a continuous process
• Only as a batch process
• Either as a continuous or batch process

Answer 68

Either as a continuous or batch process

Question 69

Centrifugation can be used on:

• Must only
• Wine only
• Wine as well as must

Answer 69

Wine as well as must

Question 70

How does centrifugation work?

Answer 70

It’s a machine that has a rapidly rotating container which uses centrifugal force to separate solids from liquids.

Question 71

What are the advantages of centrifugation?

Answer 71

1. It clarifies must quickly;
2. Can be used continuously, which saves time and money.

Question 72

What are the disadvantages of centrifugation?

Answer 72

1. Equipment is expensive to buy;
2. Used only in wineries that need to process large volumes of must quickly;
3. Increases the must’s exposure to oxygen unless the machine is flushed with inert gas.

Question 73

What is the common clarifying agent added to must which helps break down pectins in the must?

Answer 73

Pectolytic enzymes

• They only aid the clarification of must, not wine;
• They encourage rapid separation between the liquid juice and solids.

Question 74

White wines ferment at cooler temperatures than red wines, but winemakers can use very cool or slightly warmer fermentation temperatures for their white wines.

What are the benefits of each?

Answer 74

Very cool fermentation temperatures (~15°C / 59°F) help produce desired fruity, volatile aroma and flavor compounds;

Slightly warmer temperatures (17–25°C / 63–77°F, or higher) promote yeast health and avoid the production of certain esters, e.g. isoamyl acetate (banana). Slightly warmer temperatures are favored for wines that will see oak.

Question 75

Stainless steel tanks are the vessels of choice when a winemaker is making which style of white wine:

• Fruity, floral whites
• Neutral white wine
• Orange wines

Answer 75

Fruity, floral whites

Question 76

What are the advantages (and one disadvantage) of fermenting in small oak barrels?

Answer 76

Advantages:

1. Wines have deeper color, fuller body, more integrated oak-derived aromas;
2. Small size of barrels increases lees contact, which contributes texture;
3. Provides more blending options since every barrel will be different.

Disadvantage:

1. More labor intensive due to monitoring several barrels instead of one large vessel, which can drive up costs.

Question 77

What are the effects of malolactic conversion on wine?

Answer 77

• Reduction in acidity;
• Increase of pH;
• Increase in microbiological stability;
• Modification to the flavors of wine (butter).

Question 78

Why is malolactic conversion avoided in certain white wines?

Answer 78

To preserve the distinctive, primary aromatics of the grape

Question 79

What are the aims of aging wine sur lie?

Answer 79

1. Give the wine more body;
2. Soften the mouthfeel;
3. Help to stabilize the wine;
4. Protect the wine from oxygen.

Note: if lees aging is not properly managed, off-odors and unpleasant reductive compounds may develop.

Question 80

Lees stirring is also called ___.

Answer 80

Bâtonnage

Question 81

What are some of the beneficial effects from bâtonnage?

Answer 81

• Increases the release of yeast compounds into the wine;
• Introduces oxygen exposure;
  
  • this increases the effects from the lees and decreases fruity flavors;
  • reduces the development of reductive sulfur compounds and off-aromas.

Question 82

What are the three main ways of producing wine with residual sugar?

Answer 82

1. Concentrating the sugar in the grape must;
2. Stopping the fermentation before dryness;
3. Blending a sweetening component into the wine.

Question 83

What are the four methods of concentrating grape must?

Answer 83

1. Drying grapes on the vine;
2. Drying grapes off the vine;
3. Noble rot;
4. Freezing the grapes.

Question 84

What happens to grapes when they’re left to dry on the vine?

Answer 84

1. They shrivel;
   
   • water is lost by grape transpiration and the sugars concentrate;
2. Flavors develop into very ripe or extra-ripe flavors.

Wine made from grapes like this are called Late Harvest or their local equivalent.

Question 85

What is the benefit of cutting or breaking off a cane of the vine a short time before harvest in order to dry out the grapes that are still attached to that cane?

Answer 85

1. The grapes shrivel more quickly than they would if they were still attached to the rest of the vine, concentrating the grapes’ sugars, acids and flavors faster;
2. Reduced hang time lowers risk of grey rot;
3. Some grapes will exhibit very high levels of sugar without extra-ripe flavors.

Question 86

What happens in the process of drying grapes off the vine?

Answer 86

1. Causes water inside the grapes to evaporate, thereby concentrating the acids, sugars and flavors;
2. Speed up drying;
3. Avoids the development of grey rot.

Question 87

What are the conditions needed for Noble Rot to develop?

Answer 87

Humid, misty mornings followed by sunny, dry afternoons

Question 88

How does Botrytis cinerea attack grapes?

What are the distinctive aromas attributed to Noble Rot?

Answer 88

• Damp, humid mornings allow the fungus to develop on the grapes;
• The fungus punctures the grape skin, leaving tiny holes;
• Warm sunny afternoons slow the development of the rot and cause water to evaporate from the grape, concentrating its sugars, acids and flavors.

Distinctive aromas of Noble Rot include honey, apricot, citrus zest, ginger and dried fruits (some tasters also include saffon!).

Question 89

How can Botrytis cinerea go from being Noble Rot to Grey Rot?

Answer 89

If conditions are too damp, the fungus will develop too fast and split the grapes, encouraging infections.

Question 90

Grapes affected by Noble Rot are not easy to process in the winery.

What steps do winemakers have to take in order to process these grapes?

Answer 90

1. Chilling the must;
2. High doses of SO₂;
3. Use inert gases to minimize the oxidation of the must.

Question 91

What happens to the water in grapes if they’re left to freeze on the vine?

Answer 91

The water freezes and turns to ice, so when the grapes are picked and pressed this ice stays behind in the press and the sugars of the resulting juice is intensely concentrated.

Question 92

At what temperature can Canadian Icewines be harvested?

Answer 92

−8°C / 18°F or below

Question 93

What are some of the characteristics needed for vines used in Ice Wine production?

Answer 93

The vines need to:

• Be winter-hardy;
• Produce grapes with resilient skins that give protection from disease;
• Withstand the strain of freeze–thaw cycles.

Question 94

Picking grapes in the autumn and then freezing them at a winery to later be used for sweet wine production is called ____.

Answer 94

Cryoextraction

Question 95

What is the most common way of stopping fermentation to create a sweet wine?

Answer 95

• By chilling the wine to below 10°C /50°F and/or adding a high dose of SO₂ to inhibit the yeast;
• It is then racked off its sediment and sterile filtered to ensure fermentation does not start again later on.

Question 96

What is the easiest way of producing a wine with residual sugar?

Answer 96

Blending in a sweetening component

This allows the winemaker the most control and is best suited for the production of inexpensive wines made in high volumes.

Question 97

What are the most common sweetening components used to make sweet wines?

Answer 97

1. Sugar;
2. Rectified concentrated grape must (RCGM);
3. Unfermented grape juice.

Question 98

What are the benefits of using RCGM as a sweetening component?

Answer 98

• Neutral in flavor as it’s just the sugar from the grape;
• Can use less of it to sweeten wine;
• Inexpensive.

Question 99

Many of the choices involved in red winemaking are focused on the extraction of ____, ____, and ____.

Answer 99

Anthocyanins, tannins, and flavors from the grape skins

Question 100

What four factors affect extraction in red winemaking?

Answer 100

1. Temperature
   
   • higher temperatures result in greater extraction;
2. Time on skins
   
   • the longer the skin contact, the greater the extraction;
3. Cap management
   
   • the more the skins are mixed through the juice, the greater the extraction;
4. The extraction medium
   
   • is the solution more water (read: grape must) or more alcoholic (wine)?

Question 101

Anthocyanins as single molecules are not that stable. However, when they combine with ___, they become more stable, thereby increasing color stability.

What helps to facilitate this reaction?

Answer 101

• Tannins
• Oxygen helps facilitate this reaction (this means that processes that encourage oxygen into the wine – barrel aging, microoxygenation – help with color stability)

Question 102

The broad majority of red wines are made using whole cluster or destemmed berries?

Answer 102

Destemmed berries

Question 103

Select the correct answer.

Q. What is the chief aim of pre-fermentation maceration?

1. Extract maximum color, flavor, and tannins
2. Extract color and flavor without extracting tannins
3. Extract maximum tannins without extracting color and flavor

Answer 103

2. Extract color and flavor without extracting tannins

Question 104

Anthocyanins are soluble in:

• Both must and wine
• Must only
• Wine only

Answer 104

Both must and wine

Question 105

Tannins are more soluble in:

• Alcoholic liquids
• Acqueous liquids

Answer 105

Alcoholic liquids

This is why tannins aren’t meaningfully extracted during the maceration process as the must doesn’t have any alcohol, at least at this stage.

Question 106

Red grapes are typically cold soaked around what temperature?

What does this reduce?

Answer 106

~ 4–10°C / 39–50°F

This reduces:

• the rate of oxidation
• microbial spoilage
• spontaneous fermentation

Question 107

Cold soaks, or pre-fermentation macerations, usually last about how long?

Answer 107

3–7 days

Question 108

During the 3-7 days of cold soaking, the grapes are punched down and/or the fresh must is pumped over the grapes.

What does this help with?

Answer 108

• Aids in slower extraction which can be monitored and controlled;
• Inhibits the growth of spoilage microbes that need oxygen.

Question 109

Name two maceration techniques that use heat in aiding extraction.

Answer 109

1. Flash détente;
2. Thermovinification.

Question 110

To what temperature is the must heated for thermovinification?

Answer 110

~50–60°C / 122–140°F, sometimes higher

The time spent macerating at this temperature can range from a number of minutes to several hours; generally, the higher the temperature, the shorter the maceration.

Question 111

To what temperature are destemmed grapes heated when employing flash détente?

What happens in flash détente?

Answer 111

85–90°C / 185–194°F and then rapidly cooled under a vacuum

This process takes place in as little as two minutes. (The short time at high temperatures limits the risk of ‘cooked’ flavors developing.) The process bursts the cells in the grape skins, allowing a very rapid extraction of anthocyanins and flavors.

Question 112

Why do wines produced using thermovinification or flash détente have difficulty with color stability?

Answer 112

Because there is not enough tannin to bind with the anthocyanins to form more stable compounds – remember, tannins are better extracted in alcoholic solutions and in neither of these techniques is alcohol present.

Thermovinification and flash détente are techniques best reserved for inexpensive reds meant to be drunk young.

Question 113

Why are flash détente and thermovinification beneficial for grapes affected by botrytis?

Answer 113

Because the high temperatures of both techniques denature oxidative enzymes (laccase) produced by the rot.

Note: flash détente can also be used as a treatment for smoke taint.

Question 114

What are the five major cap management techniques?

Answer 114

1. Punching down;
2. Pumping over;
3. Rack and return;
4. Ganimede® tanks;
5. Rotary fermenters.

Question 115

Performing cap management does two key things:

• Promotes extraction + redistributes heat
• Inhibits extraction + promotes spontaneous fermentation
• Encourages microbial growth + tannin extraction

Answer 115

Promotes extraction + redistributes heat

Question 116

How do choices of cap management influence the style of a wine?

Answer 116

1. The winemaker can change the frequency of mixing and the time spent mixing, determining extraction;
2. When the mixing occurs during fermentation the winemaker can influence which compounds are extracted;
3. Temperature during mixing can affect which compounds are extracted and to what degree.

Question 117

What is the French term for ‘punching down’?

Answer 117

Pigeage

Question 118

What is the French term for ‘pumping over’?

Answer 118

Remontage

Question 119

What is the French term for ‘rack and return’?

Answer 119

Délestage

Question 120

Why is rack and return more extractive than pumping over or punching down?

Answer 120

Because it breaks up the cap and mixes the juice and skins thoroughly; due to its effectiveness it’s only used 1-3 times during fermentation.

It is commonly used for red wines where medium to high levels of extraction are desired.

Question 121

How do Ganimede® tanks work?

Answer 121

They bubble CO₂ or oxygen up through the must/wine which breaks up the cap quickly and effectively, thereby increasing extraction of color, flavor, and tannin.

Question 122

Why are rotary fermenters so effective at extracting color, flavor, and tannin?

Answer 122

1. Because of their horizontal orientation, the tank increases the surface area between the grape skins and the juice;
2. The whole tank rotates and its internal blades break up the cap and mixes the skins and juice;
3. The tank can be programmed to rotate as many times and for a certain amount of time as the winemaker desires.

Question 123

What are two other maceration options used in addition to cap management techniques to increase color, flavor, and tannin in the final wine?

Answer 123

1. Must concentration;
2. Co-fermentation.

Question 124

What is ‘must concentration’?

Answer 124

When some of the juice is drawn off immediately after crushing (and before fermentation starts) which increases the volume of skin-to-juice ratio.

Question 125

What is the French term for ‘must concentration’?

What do winemakers usually do with the juice they bled off?

Answer 125

Saignée

They usually make rosé

Question 126

Define co-fermenting (or co-fermentation).

Answer 126

When different grape varieties ferment together in the same vessel

Question 127

When a winemaker is employing whole bunches in their fermentation, why do they need to ensure the bunches are fully ripe?

Answer 127

Because unripe stems can add unpleasant green flavors and bitter tannins instead of the “spicy” and “herbal” flavors when stems are fully ripe.

Question 128

The objective of whole-berry/whole-bunch fermentations is to create what kind of environment for the fruit?

Why?

Answer 128

An oxygen-free environment

To add texture and create distinctive aromas in the final wine.

Question 129

What happens to the grapes when they’re fermented as whole berries or whole bunches?

Answer 129

1. The grapes change from aerobic respiration to anaerobic metabolism (intracellular fermentation [carbonic maceration]);
2. Glycerol levels increase, which adds texture to the final wine;
3. A range of distinctive aromas is created inside the grape from the intracellular fermenation (banana, kirsch).

Question 130

What are the three forms of whole-berry / whole-bunch fermentation?

Answer 130

1. Carbonic maceration;
2. Semi-carbonic maceration;
3. Whole berries/bunches with crushed fruit.

Question 131

In carbonic maceration, once the alcohol level within the grapes reaches ___% the grape skins split and the grapes release their juice.

Answer 131

2%

Question 132

In carbonic maceration, how is that 2% alcohol achieved within the berries (where does it come from)?

What effect does this have on the must?

Answer 132

Malic acid within the grape is broken down to create ethanol, which reduces malic acid levels lowering the total acidity (and raising the pH) of the must

• the must can see malic acid reductions of up to 50%

Question 133

Besides distinctive aromatics, what are the two key features of a wine that has undergone carbonic maceration?

Answer 133

1. Intensely colored;
2. Low in tannin.

Question 134

Why isn’t new oak used on wines that have been fermented with carbonic maceration?

Answer 134

Because the flavors of the oak (vanilla, toast) would interefere with the fruity, low tannin, candy-like flavors of the wine.

Wines made with carbonic maceration also are meant to be drunk within a year of harvest, so it doesn’t make financial sense to use new oak on these wines.

Question 135

What is the main difference between carbonic maceration and semi-carbonic maceration?

Answer 135

No CO₂ is added to the tank in semi-carbonic maceration.

In semi-carbonic maceration, the ambient yeasts start to ferment the juice that has been released from the grapes, which have burst under the sheer weight of all the whole bunches. CO₂ is produced from those ambient yeasts metabolizing the sugar in the released juice which fills the tank, and then the remainder of the whole berries/bunches undergo carbonic maceration.

Question 136

If a winemaker uses semi-carbonic maceration but they want to produce a more serious wine with slightly more concentration, body and tannin, what can they do after the semi-carbonic maceration has completed?

Answer 136

1. Continue alcoholic fermentation on the skins and incorporate punching down or pumping over;
2. Post-fermentation maceration and/or maturation in oak to add complexity.

Question 137

What is the thought behind adding whole berries/bunches to crushed fruit and how that affects the final wine?

Answer 137

Many winemakers believe it lends a smoother texture and more vibrant and fresh primary aromas (than crushed fruit fermentations) to the final wine.

Question 138

Winemakers who aim to produce fruity, low tannin wines will generally ferment at relatively cool temperatures, ___ºC.

Winemakers who want greater extraction and the concentration and tannin structure to age their wine will ferment at slightly warmer temperatures, ___ºC.

Answer 138

Cool temperatures: 20°C / 68°F

Warm temperatures: 30°C / 86°F

Question 139

Post-fermentation maceration is generally conducted on:

• High-volume, inexpensive wines
• Premium and super-premium wines

Answer 139

Premium and super-premium wines

Question 140

Why do winemakers employ post-fermentation maceration? What does it do for the wine?

Answer 140

This practice is thought to further extract tannins and encourage tannin polymerization, with the aim of improving tannin structure and texture and the wine’s aging potential.

Question 141

When are red wines pressed?

Answer 141

When no more extraction is desired, so the timing differs depending on the style of wine being produced.

• If carbonic was used, maybe the grapes are pressed when the fermenting must reaches 2%;
• The wine might be pressed before alcoholic fermentation is complete so it can finish fermentation in oak barrels;
• Maybe the wine is pressed after post-fermentation maceration because the winemaker wanted greater tannin extraction.

Question 142

Malolactic conversion is normally carried out on red wines.

What does malolactic conversion increase and decrease in the wine?

Answer 142

• Decreases the acidity of the wine;
• Increases the pH of the wine.

Question 143

What are the key benefits of maturing red wine in oak barrels?

Answer 143

• The barrels impart flavors of the oak (vanilla, clove);
• Barrels provide gentle oxidation:
  
  • helps soften tannins;
  • helps develop tertiary aromas and flavors that can enhance complexity and quality.

Question 144

What are the three chief ways of making rosé wine?

Answer 144

1. Direct pressing (also known as ‘Vin Gris’);
2. Short maceration;
3. Blending.

Question 145

In direct pressing for rosé wines, how does the winemaker control the final color of the wine?

Answer 145

• The pressure used when pressing;
• The duration of the pressing time;
• How much press juice is used.

Question 146

Rosés made with short maceration produce wines that are deeper in color and more pronounced in flavor than those made using ___ ___.

Answer 146

Direct pressing

Question 147

In the blending method for rosé production, the white and red wines are:

• Blended prior to fermentation
• Blended during fermentation
• Blended after they’ve already fermented

Answer 147

Blended after they’ve already fermented

This allows the winemaker total control over the final hue.

Question 148

Rosé wines are usually fermented at:

• Cool temperatures (12–16°C / 54–61°F)
• Warm temperatures (30°C / 86°F)

Answer 148

Cool temperatures (12–16°C / 54–61°F)

This promotes the production and retention of aroma compounds.

Question 149

Which vessel is most often used in rosé production?

Answer 149

Stainless steel tanks

They are neutral vessels and allow temperature control.

Question 150

How do rosés with residual sugar typically get their sweetness?

Answer 150

1. By stopping the fermentation before it reaches dryness;
2. By blending a sweetening component into the dry rosé.

Question 151

Malolactic conversion in rosé wines is usually:

• Encouraged
• Avoided

Answer 151

Avoided

The buttery flavors from malo are undesirable in rosé wines; plus, malo decreases acidity and rosé wines are meant to be refreshing.

Question 152

Because the appearance of rosé wines plays a big role in their appeal, the majority of rosé wines will be ____ and ____ to increase their clarity.

Answer 152

Fined and filtered

Question 153

Rosé wines that have some residual sugar must be ____ filtered to remove any unwanted microbes that could cause problems later after finishing and packaging.

Answer 153

Sterile