16.1 White Winemaking: Transportation to Winery and Grape Reception

Question 1

What is skin contact?

Answer 1

The process of leaving the juice in contact with the skins to extract compounds from the skins (similar to cold soaking in red winemaking)

Question 2

In white grapes, what is the main purpose of skin contact?

Answer 2

1. To enhance the extraction of aroma and flavour compounds and precursors
2. To enhance the texture of the wine by extracting a small amount of tannin

Question 3

If a white wine has too much skin contact, what may result?

Answer 3

Can make white wines taste bitter and feel coarse in the mouth

Question 4

For the majority of white wines, what happens after harvest?

Answer 4

• minimal or no skin contact
• crushed and then pressed immediately
• or (whole bunches) pressed without prior crushing

Question 5

In white grapes, where are the principle aroma and flavour characteristics found?

Answer 5

In the pulp

Question 6

To limit the amount of contact between the juice and skins (and reduce oxidation), what can winemakers do?

Answer 6

Load the press with whole bunches of uncrushed grapes

Question 7

In what types of wines is no or minimal skin contact typical?

Answer 7

• wines where delicate fruity flavours, minimal colour and a smooth mouthfeel are desired
• wines designed to be drunk early (tannins would not have time to soften)
• if fruit is at all under-ripe (bitter flavours and astringent tannins)

Question 8

What are the costs associated with skin contact? Thus, what wine typically don’t see any skin contact?

Answer 8

• slows processing
• requires use of equipment and labour
• less likely to be carried out on inexpensive wines from a logistics and cost perspective

Question 9

On what types of grapes is skin contact most effectively used? Give examples.

Answer 9

• aromatic grape varieties that have lots of aroma compounds that can be extracted
  (Riesling, Gewurztraminer, Viognier, Muscat, Sauvignon Blanc)

Question 10

What does skin contact add to a wine?

Answer 10

• maximises flavour extraction

- enhances texture

Question 11

What can be a controversial downside of skin contact?

Answer 11

• leads to homogenisation

- reduces variations between grape varieties and different vineyard sites

Question 12

Name 2 key factors that can influence extraction during skin contact.

Answer 12

1. Time

2. Temperature

Question 13

How long does skin contact typically last?

Answer 13

1-24 hours or longer

Question 14

What is the effect of time on skin contact?

Answer 14

with greater time on skins leading to greater extraction of flavour and tannins

Question 15

Why may a producer chill the juice during skin contact?

Answer 15

1. reduces the rate of extraction of flavours and tannins
2. permits more control
3. reduces the rate of oxidation and microbial spoilage, (including likelihood of a spontaneous fermentation)

Question 16

At what temperature is skin contact typically carried out?

Answer 16

below 15°C (59°F)

Question 17

After skin contact, what happens?

Answer 17

• The wine is usually pressed to separate the skins and juice
• Then fermentation begins

Question 18

What is an ‘orange wine’?

Answer 18

• extreme end of the skin contact spectrum
• wines made from white grapes that are fermented on their skins (and may undergo post-fermentation maceration) without temperature control or sulfur additions
• often amber-coloured

Question 19

What causes the colour of orange wines?

Answer 19

develops due to the oxidation of compounds extracted from the grape skins

Question 20

What do orange wines taste like?

Answer 20

• do not taste like typical white wines
• usually dry
• notable levels of tannins
• taste mainly of tertiary characteristics (nuts, dried fruit.)

Question 21

Skin contact - why NOT?

Answer 21

Majority whites crushed & pressed imm after harvest

• limits contact between juice and skin
• min skin contact suits wines with delicate flavours, light colour, and smooth mouthfeel
• typical choice for wine to be drunk early
• Definite choice if fruit is under-ripe
• time on skins requires space, equipment, skills - all adds to cost and not likely on inexp wines.

Question 22

Skin contact - why and how?

Answer 22

Process of leaving juice on the skins

• to extract aroma/flavour/precursors
• enhance texture by extracting small amount of tannin.
• wine is chilled at <15 degC - ROTSO & spontaneous fermentation controlled
• leave on skins 1 - 24 hrs (or as per producer)
• wine is then pressed and fermented off skins.

Benefit:
max aroma/flavour suits varietes with lots of this - riesling, gewurtz, SB, Viognier
!potential for bitterness/coarse texture

Standard practice for orange wines that will be fermented on the skin, end up dry, with tannins, and
oxidised flavours of caramel, nuts, dried fruit.