13.8 General Winemaking Options: Post-Fermentation Adjustments

Question 1

What 5 adjustment can be made after fermentation?

Answer 1

• Acidity
• pH
• Sweetening
• Removal of alcohol
• Colour

Question 2

Why must only small adjustments be made post-fermentation?

Answer 2

Must be careful to not upset the balance of the wine

Question 3

Why might a producer remove alcohol after fermentation?

Answer 3

• to produce a reduced alcohol wine (e.g. below 5.5 per cent)
• to adjust the level of alcohol marginally

Question 4

What is the simplest way to marginally adjust the level of alcohol after fermentation? What is the downside?

Answer 4

• Add water

- Reduces the intensity of flavour

Question 5

Name 2 high-tech ways to remove alcohol after fermentation. Which is most common?

Answer 5

1. Reverse osmosis (*most common)

2. Spinning cone

Question 6

What is reverse osmosis? How costly is this method?

Answer 6

• A form of cross-flow filtration that removes a flavourless permeate of alcohol and water, which can be distilled to remove the alcohol. The permeate is then blended back to recreate the wine.
• The equipment can be rented or bought, but is generally costly.

Question 7

What is a spinning cone? How costly is this method?

Answer 7

• A device that first extracts volatile aroma compounds from wine and then removes the alcohol. The flavour components are then blended back into the wine of the desired alcohol level.
• This technology is only financially viable for large volumes of wine.

Question 8

In the EU what post-fermentation alcohol reduction methods are permitted?

Answer 8

Within specified limits:

• Reverse osmosis
• Spinning cone

Question 9

What post-fermentation color-altering techniques may be used?

Answer 9

• Fining: reduce unwanted colour tints

- Add MegaPurple: grape-derived colouring agent, used to enhance color intensity in a red wine

Question 10

Name 1 region where adding MegaPurple not permitted.

Answer 10

Ribera del Duero