Freezing grapes on the vine

Question 1

Explain the process of freezing grapes on the vine

Answer 1

Healthy grapes left on the vine- late autumn/winter.
When freeze temp arrives, water in pulp turns to ice.
When pressed, ice remains in press, resulting juice- highly concentrated.
Vines need to be winter hardy and resilient skins- eg riesling.

Question 2

What is cyroextraction?

Answer 2

Picking grapes in autumn, then freezing them in the winery.