16.3 White Winemaking: Hyperoxidation

Question 1

What is hyperoxidation?

Answer 1

The technique of deliberately exposing the must to large quantities of oxygen before fermentation

Question 2

What happens to the wine during hyperoxidation?

Answer 2

• targets the compounds in the must that oxidise most readily
• as they oxidise, these compounds turn the must brown
• during fermentation the compounds precipitate, returning the wine to its normal colour

Question 3

What are the main aims of hyperoxidation?

Answer 3

• to produce wines that are more stable against oxidation after fermentation
• to help to remove bitter compounds that can come from unripe grape skins, seeds and stems

Question 4

What grapes are best suited for hyperoxidation? Give an example.

Answer 4

• neutral grape varieties
• e.g. Chardonnay
• Why? It can destroy some of the most volatile aroma compounds found in the must

Question 5

What grapes are not well suited for hyperoxidation? Give an example.

Answer 5

• aromatic, fruity, or herbaceous varieties
• e.g. Sauvignon Blanc
• Why? can reduce the levels of volatile thiols and methoxypyrazines that give SB its desired flavours

Question 6

What are the costs associated with hyperoxidation?

Answer 6

• equipment required for hyperoxidation is not particularly expensive
• extra step in process
• requires labour to set up and monitor