Chapter 7 - Common Elements in Winemaking

Question 1

Name the parts of the grape

Answer 1

Skin - high concentration of flavour compounds. Also contains tannins and colour compounds

Seeds and stems - contain tannins and bitter oils

Bloom - the waxy surface that covers the skin

Pulp - contains water, sugar and acids (mostly tartaric, a bit malic)

Tannins

Question 2

What is the chemical process of oxygen reacting with wine reffered to as?

Answer 2

Oxidation

Question 3

What flavours does oxidation take away from wine?

Answer 3

Primary fruit characteristics

Question 4

What anti-oxidant is often used?

Answer 4

Sulfur Dioxide

Question 5

What are some techniques to counter the effects of oxygen in winemaking?

Answer 5

• harvest at night when it is cooler
• keept the grapes chilled as long as possible during and after harvest
• keep the grapes and juice away from oxigen with airtight equipment

Question 6

Why do lower temperatures help against oxidation?

Answer 6

Chemical processes go slower in lowe temperatures

Question 7

What gasses are used to keep machinery airtight?

Answer 7

Nitrogen and Carbon Dioxide

Question 8

What is winemaking with the least amount of oxigen referred to as?

Answer 8

Anaerobic winemaking

Question 9

Can you mature wines that have been made anaerobicly in oak vessels

Answer 9

No, wines made in that way don’t benefit from any contact with oxigen during maturation

Question 10

What airtight maturing vessels are there?

Answer 10

• stainless steel

- cement lined with epoxy

Question 11

What can contact with very small amounts of oxygen during ripening do to wines?

Answer 11

• soften tannins in red wines
• give complexity to flavours: fruit will fade into teriary characters like earth or leather
• colour changes. Red becomes paler and can turn brown, white becomes deeper in colour and becomes a bit orange

Question 12

Why are wines rarely kept more than 2 years in barriques?

Answer 12

Because of its small size (225 liters), the relative surface touching the oak (and thus oxigen) is very big compared to larger vessels

Question 13

Why would barrels not fully be topped up? Examples

Answer 13

For fortified wines that have a deliberate oxidative style this is a technique used to create nutty, caramel and toffee flavours.

Olorosso, Tawny Port and Rutherglen Muscat

Question 14

What is the risk of too much oxigen exposure during ageing?

Answer 14

Too much loss of fresh fruit flavours and stale smell

Question 15

What is SO2 and what is it used as?

Answer 15

Sulfur Dioxide

• antioxidant
• antiseptic

Question 16

Why is the use of SO2 restricted?

Answer 16

It can be toxic (though the concentration in wine is lower than dried fruit)

It can cause allergic reactions

Question 17

What is a ‘bound’?

Answer 17

SO2 when it reacts with O2. It loses its protective ability and becomes a ‘bound’

Question 18

What does SO2 do, other than protect against oxigen?

Answer 18

It kills off bacteria and yeasts (except for the one that does the alcoholic fermentation)

Question 19

What other use, aside from micro oxidation, do oak vessels have?

Answer 19

Adding tannin (and thus structure)
Adding flavour (like vanilla, toast, smoke and cloves)

Question 20

What are 4 important factors in choosing the type of oak vessel

Answer 20

• species and origin. Oak from different species or origins can have different characteristics (flavour etc)
• size. Small vessels have more impact than big vessels (due to relative surface contact
• age. The amount of flavour a barrel gives to the wine deminishes with every useage
• production. For instance toasting, which gives distinct flavours to the wine

Question 21

What is a piece, and what is a barrique?

Answer 21

Piece is an oak barrel of 228 liters

Barrique is 225 liters

Question 22

What are the 2 main origins of oak vessels?

Answer 22

American Oak and European (French, Hungarian, Russian)

Question 23

After how many times do oak vessels lose most of their flavour?

Answer 23

After 4 uses

Question 24

What are other ways than oak barrels to get the aroma’s and tannins in the wine?

Answer 24

Chips or staves

Question 25

What are 2 ways temperature be controlled in stainless steel vessels?

Answer 25

Sleeves on the outside Coils on the inside

Question 26

Why do some wine makers prefer concrete vessels?

Answer 26

The thick shells help to regulate temperature

Question 27

Why should damaging the seeds be avoided during crushing?

Answer 27

It releases bitter and astringent oils an tannin

Question 28

When is pressing done?

Answer 28

In white wines before fermentation, in red wines usually after fermentation

Question 29

What is free run juice?

Answer 29

The juice that comes from crushing, when the skin is lightly broke

Question 30

What does a traditional (basket) press look like?

Answer 30

It is vertical, with a plate that is raised or lowered by using a screw or lever. Still used in Champagne

Question 31

How does a pneumatic press work?

Answer 31

With an inflateable tube within a horizontal cylinder, sometimes built within a closed stainless steel tank to minimize contact with oxygen

Question 32

Name 3 components that can be adjusted in a wine (or must)

Answer 32

Sugar, alcohol and acid

Question 33

What is the must weight?

Answer 33

The level of sugar in the must

Question 34

What is RCGM?

Answer 34

Rectified Concentrated Grape Must, a sypury liquid, used to ‘enrich’ the grape must to get higher levels of alcohol

Question 35

When is enrichment done?

Answer 35

In cooler climates, adding RCGM, helps raise alcohol levels when grapes don’t get enough sugar on their own

Question 36

What is a danger of enrichment?

Answer 36

The wine may not have enough flavour to balance the higher levels of alcohol

Question 37

What is chaptalisation?

Answer 37

Enrichment with sources other than RCGM, for instance sugar beets

Question 38

What is another way, other than enrichment, to get more alcohol in the wine and what is the risk here?

Answer 38

Remove water from the juice. It concentrates the sugars, but also everything else (even flaws)

Question 39

Why and where is acidification done?

Answer 39

Usually only in warmer regions, where acid levels can drop too far during ripening

Question 40

How is acidification done?

Answer 40

By adding tartaric acid in powder form

Question 41

How, why and where is deacicidication done

Answer 41

Usually in colder regions, where acid levels have not dropped enough during ripening, by using alkali

Question 42

What is acoholic fermentation?

Answer 42

The conversion of sugar into alcohol and CO2

Question 43

What are the by-products (4) of alcoholic fermentation?

Answer 43

CO2 Alcohol Heat Flavour compounds

Question 44

What is the yeast responsible for most fermentation in wine?

Answer 44

Saccharomyces Cerevisae

Question 45

Why is Saccharomyces Cerevisae a good yeast for alcoholic fermentation?

Answer 45

Its is very resistant to alcohol and SO2

Question 46

What is the lowest temperature required for alcoholic fermentation?

Answer 46

5 *C

Question 47

When does alcoholic fermentation stop?

Answer 47

When sugar runs out When nutrients other than sugar run out When the temperature of the juices reaches over 35 *C When the alchol level becomes too high (this requires a lot of sugar to begin with)

Question 48

How can the fermentation be stopped before all the sugar is consumed?

Answer 48

By adding SO2 or grape spirit to kill the yeast Or by removing the yeast using filtration after chilling the wine below 5 *C

Question 49

Why are ambient (indiginous) yeasts not suitable for high volume wine production?

Answer 49

Winemakers cannot what yeasts exactly are present, which may result in different flavours between batches and longer fermentation times

Question 50

In what way does fermentation temperature influence the final wine?

Answer 50

Fermenting at low temperatures avoids the loss of volatile aroma’s that have a floral character and encourages the development of fruity flavours. Higher temperatures promote extraction of colour and tannin

Question 51

What is MLF

Answer 51

Malolactic fermentation. Which takes place after alcoholic fermentation. Turning malic acids into lactic acids (which are softer to the palate)

Question 52

What is the effect of MLF?

Answer 52

It creates softer acids, reduces acidity, and creates buttery flavours. A byproduct is also CO2

Question 53

How is MLF encouraged?

Answer 53

Raising the temperature during fermentation

Question 54

What are lees?

Answer 54

Dead yeast cells and grape fragments

Question 55

What 2 types lees are there?

Answer 55

Gross and fine

Question 56

Why would a wine maker keep the wine in contact with the lees?

Answer 56

It adds texture and flavour

Question 57

What are the components of a typical still wine?

Answer 57

``` Ethanol Tannins and colour Water Acids Sugars Aroma’s and flavour compound ```

Question 58

Why would a winemaker store its wine for the shortest amount of time possible in an inert vessel (wine quality, not economic)

Answer 58

To keep as many primary fruit aroma’s as possible

Question 59

What does a wine need in order to survive medium to long term ageing?

Answer 59

Tannins Acidity and/or alcohol And flavours that can develop in an interesting way

Question 60

When is blending most often done?

Answer 60

After fermentation or during maturation

Question 61

Why is blending done?

Answer 61

Improve balance, attain consistency and/or achieve a certain style

Question 62

Why is blending for consistancy so inportant?

Answer 62

Wines ripened in different vessels can show slight differences for a number of reasons. To get one consistant product in all of the bottles, the wines are often blended. Differences can arise due to variations in the oak, vineyard site or harvesting time.

Question 63

What can winemakers do to create as many blending options as possible? (6)

Answer 63

Seperate press fractions Fermenting or maturing in different types of vessels Only allowing a portion of the wine to go through MLF Using different varieties Vinyard plots Vintages

Question 64

What are the 3 main techniques for clarification?

Answer 64

Sedimentation Fining Filtration

Question 65

Why would a winemaker NOT clarify its wine?

Answer 65

If they believe it can harm the character of the wine

Question 66

What is sedimentation and racking?

Answer 66

When winemakers let gravity pull suspended particles (such as gross lees) to the bottom of the liquid and then pump the clear liquid off of the sediment. This is called racking, and can be done at multiple moments and stages (all after fermentation).

Question 67

What is fining?

Answer 67

The process of speeding up the clumping together of certain constituents, in order to filter them out as a part of clarifying the wine.

Question 68

What are the 2 types of filtration?

Answer 68

Depth filtration - the wine is passed through thick layers of material Surface filtration - using very fine sieves. Sometimes so fine that it can be called sterile filtration

Question 69

When is a wine considered stable?

Answer 69

If it changes in a slow, predictable manner over a specified time frame

Question 70

Apart from clarification, what are 3 important areas that require stabilisation?

Answer 70

Tartrate stability, microbiological stability and oxygen stability.

Question 71

What are tartrates?

Answer 71

It is cristalized tartaric acid. They are harmless and flavourless. Cold temperatures speed up the process of cristalization. (This fact can be used by winemakers to force tartrate stability)

Question 72

What aids microbiological stability?

Answer 72

Alcohol, lack of nutrients and acidity.

Question 73

Name 2 styles that are naturally resistant to microbiological spoilage

Answer 73

Fortifies wines - because of the high alcohol levels Dry, high acid, MLF wines - alcohol, lack of nutrients and acidity.

Question 74

What are 2 ways to sterilize a wine?

Answer 74

SO2 and sterile filtering

Question 75

What happens to wine if a wine is exposed to oxygen (during or) after bottleing?

Answer 75

Losing fresh fruit aroma’s and turning brown

Question 76

Why is wine mostly packaged glass bottles?

Answer 76

Cheap, sturdy and portable. And completely airtight (the glass itself)

Question 77

What is the downside to using glass bottles?

Answer 77

Heavy and rigid. Which adds transport costs and takes op much space.

Question 78

Why is plastic not the beet option for storing wine?

Answer 78

Tiny amounts of oxigen pass through, which puts the wine at risk within about 18 months. So it is good for early drinking wines, but nothing that needs ageing.