16.2 Pressing the Grapes (white wine making)

Question 1

Why is gentle pressing needed when making white wine?

Answer 1

Gentle pressing is needed to avoid extraction of compounds from the skins and seeds (tannin, colour).

Question 2

At what stage of winemaking does a winemaker choose whether or not to destem white grapes?

Answer 2

Before being loaded into the press.

Question 3

List and describe 3 reasons why a WM would decide to keep whole bunches when pressing.

Answer 3

1) Reduces oxidation
2) Gentle: juice is low in solids
3) Stems break up mass of skins and provides channels for juice to drain

Question 4

What are 2 drawbacks when using whole bunch pressing to make white wine.

Answer 4

1) Hand harvesting = money
2) WB take up lots of room in press - fewer grapes can be loaded in each press cycle

Question 5

Is whole bunch pressing for white wine making better for smaller batches or high-volume production?

Answer 5

Smaller batches.

Question 6

Name 2 types of juice.

Answer 6

1. Free run
2. Press juice

Question 7

Describe free run juice (3 points).

Answer 7

1. Juice that can be drained off as soon as the grapes are crushed
2. Typically juice that is lowest in solids, tannin and colour
3. Lower in pH, higher in acidity

Question 8

Why might a WM make WW from 100% free run juice. Name 1 advantage and 1 disadvantage.

Answer 8

Advantage: lighter style with no tannin
Disadvantage: smaller amount produced so cost and pricing implications.

Question 9

Describe different types of press juice. Describe its composition.

Answer 9

1) Juice that runs off through pressing
2) At start, juice will be similar to free run juice but more pressure = more solids, tannins, colour
3) Lower in pH and less sugar than free run juice

Question 10

Describe press fractions.

Answer 10

Press fractions refer to a quantity of juice that is extracted with a certain amount of pressure.

Question 11

How can a winemaker use press fractions?

Answer 11

Different fractions may be blended with each other in the winemaking or maturation process to create different styles of wine.

Question 12

Describe the final press fractions. What happens to them?

Answer 12

Tannins from skins, seeds and stems are be pressed out from the high amount of pressure.
The final press fractions are too astringent or bitter.
This final fraction will be discarded.