Pomace winemaking 2 Flashcards
What are the two main types of polyphenols?
- Non-flavonoids (e.g., benzoic, cinnamic acids); 2. Flavonoids (e.g., catechins, resveratrol, anthocyanins)
What is the function of anthocyanins in red wine?
They are red pigments in grape skins responsible for red wine colour.
What is the function of tannins in wine?
Tannins provide astringency, structure, and mouthfeel; they are polymerised catechins.
What factors influence phenolic extraction in pomace wines?
Ferment temperature, cap management techniques, ferment duration, pressing method.
How does fermentation temperature affect phenolic extraction?
Higher temperatures increase extraction of colour and tannins; moderate temps favour fruity aromas and softer structure.
What happens if fermentation temperature exceeds 32ºC?
Yeast struggle to survive, leading to risk of stuck fermentation.
What is the ‘cap’ in pomace fermentation?
The floating mass of grape skins formed during fermentation, limiting skin/must contact.
What is the purpose of cap management?
To increase skin/must contact, extract phenolics, manage heat, and prevent spoilage.
What compounds can influence cap management?
Alcohol, oxygen, sulphite, added/exogenous tannins, stalk or oak tannins.
How does the duration of skin contact affect wine style?
Short (5-8 days) = light wines; Long (1-3 weeks) = full-bodied wines; Extended = softer tannins.
What happens during draining and pressing of pomace wines?
Free-run wine is drained; solids are pressed to release press wine, which may contain residual sugar.
Why must wine be kept warm after pressing?
To ensure any remaining sugar in the press wine ferments fully.
Why should pressing be gentle?
To avoid extracting harsh or bitter phenolics from pomace.
How does press wine differ from free-run wine?
Press wine has more colour, phenolics, solids, and a different flavour profile.
What determines whether press wine is blended?
The desired wine style and balance of phenolic/organoleptic properties.
What are some techniques used to influence phenolic extraction in pomace wines?
Thermovinification, flash détente, cryoextraction, enzyme use, yeast choice, electric pulsing, microwaving.
What are some inclusion techniques for pomace winemaking?
Saignee, whole berries, stem inclusion, skin inclusion, oak chips, exogenous tannins, co-pigmentation.
