Maceration
This stage of the winemaking process involves macerating the solid parts of the grape in the must to extract aromatic phenols, pigments and tannins. Maceration takes place after any crushing and before pressing. The procedure depends on the grape variety and the wine being made.
Summary of maceration steps
- Early diffusion of varietal aromas and volatile aroma precursors contained in the skin and pulp of grains.
- Capture of anthocyanins (red pigments in the bloom of red grapes), with maximum concentration in the must after few days. The same goes for flavonols, the yellow pigments found in the skins of white and red grapes.
- Gradual extraction of the tannins contained in the grape pips and skins, facilitated by the presence of ethanol, the alcohol in wine.
Traditional maceration
This maceration follows crushing and de-stemming of the bunches of red grapes: the grapes are burst and the juice macerates with the pulp, skins and seeds.
The longer this skin maceration lasts during or after alcoholic fermentation, the more colourful and tannic the wine will be.
For red wines, the must will macerate:
- a few days for light wines,
- several weeks for fuller-bodied wines and wines for ageing.
In the case of rosé bleeding wines (vinified as reds), maceration of the red grapes remains pre-fermentary and lasts only a few hours.
Aveine's Precision
Orange wine! Yes, it's also possible to vinify a white grape variety using the same method as for red wine. The must then becomes loaded with flavonols, whose gradual oxidation gives it an amber colour. Called a "white maceration wine", an orange wine combines the freshness of a white with the tannic structure of a red... For a surprising tasting experience!
Cold fermentative maceration
The red or white grapes, crushed and de-stemmed, macerate in vats at a temperature of 5 to 10°C for 12 to 48 hours. Alcoholic fermentation is thus postponed: this is alcohol-free maceration.
This skin maceration gently extracts the aromatic phenols and then the pigments, depending on how long it takes, without the must picking up too many tannins.
Ideal for maximising the aromatic profile of grape varieties with light varietal aromas, it is used for:
- some white wines and some pressed rosés,
- light reds whose delicate character the winemaker wishes to preserve.
Aveine's Precision
Hot pre-fermentation maceration, initially used to treat damaged grapes, is now being explored more and more in oenology.
Carbonic maceration
The unpressed, intact harvest macerates for one to two weeks in small, airtight vats (so that it does not crush under its own weight). The winemaker then adds CO2, which triggers the grapes' anaerobic metabolism and thus the production of ethanol in the grapes, which is not produced by alcoholic fermentation.
Cette macération carbonique, préfermentaire, permet l’élaboration de vins aromatiques, colorés et très fruités tout en étant peu tanniques. It is appreciated for the primeur red wines as well as certain rosé wines.
Aveine's Precision
Semi-carbonic maceration has the same objective, but is carried out without the addition of CO2, in large non-hermetically sealed vats. The grapes at the bottom crack under their own weight, and the yeasts begin to digest the sugars. The carbon dioxide produced by this alcoholic fermentation then activates the anaerobic metabolism of the grapes at the top of the vat. This process is used in particular for Beaujolais.