In one sentence: Whole bunch fermentation is a red-wine technique in which intact grape bunches are placed in the fermenter instead of destemming and crushing all the fruit.
Used forRed wine
Common grapesPinot Noir, Shiraz
Key riskGreen stem character
What changes when stems are included?
Stems can influence aroma, tannin, structure and fermentation behaviour. The result depends on stem ripeness, percentage used and how the bunches are positioned and handled.
Which grapes commonly use it?
The Australian Wine Research Institute notes that it is most commonly applied to Pinot Noir and Shiraz.
What can go wrong?
Green, grassy or herbal flavours and overly astringent tannins can be extracted when stems are insufficiently lignified or extraction is poorly controlled.
Is whole bunch the same as carbonic maceration?
No. Some carbonic activity may occur inside intact berries, but full carbonic maceration requires an anaerobic carbon-dioxide environment and intact fruit.