Carbonic maceration

The carbonic maceration (French: macération carbonique ) is a wine-making process for red wine production. In Beaujolais, this method is usually to generate the Beaujolais Primeur use.

Technology and metabolism

When carbonic maceration, the grapes intact as possible - no de-stemming, no crush - stored as whole grapes in the fermentation vessel. This requires hand picking and gentle transport, as well as gentle repositioning. The container is placed under CO2 shielding gas to protect the product from oxidation. The enzymes in the berries constitute about 1.5% of ethanol, glycerol and succinic acid; Malic acid is degraded. These solvents extract then turn the dyes from the grape skin and polyphenols from the seeds. The extracted berries appear milky white and burst under the pressure of the resulting CO2 formation on. The process has already been described by Louis Pasteur as intracellular fermentation.

Instead of an artificial protective gas atmosphere can also be a hybrid of the technologies may be used. For this part of the grapes is then de-stemmed conventional, mashed and fermented. The resulting fermentation carbonic acid then displaces the oxygen up. The proportion can be up to 50%. Such a hybrid form called semi- carbonic maceration.

Grapes used for the carbonic maceration should have a soft berry skin that supports this technology. This also has an impact on the later type of wine.

The more wine goes according to conventional keller technical procedures.

Type of wine

The thus resulting wine type is more fruity and light and not as strong as the tannic otherwise widespread in France wine types. This has the advantage that it is very fast consumer- capable. A long maturation period for the integration of the tannins is not required. Just six weeks after reading the product is drinkable and is bottled. The wines live from their freshness and should be drunk quickly.

The wines produced by carbonic maceration have typical aroma components that come from ingredients such as acetaldehyde, certain amino acids, ethyl acetate, glycerol and methanol, resulting in greater amounts than usual. For example, glycerol can be present in one to ten times higher concentration.

Problems in the vinification

First, the grapes must be stored very carefully without damaging the skins. The spontaneous fermentation undesirable microorganisms can bring benefits, care in the later wine for off-flavors.

By-products of metabolism described are volatile phenolic compounds, which smell strongly of bananas and tropical fruits, one also speaks of "sweet sound".

History

The semi- carbonic maceration was probably always been part of oenological practices, because the grape processing in some winemakers formed a bottleneck, and was not handled consistently. In its pure form it was accidentally discovered in France in 1934, studied as a scientist, how long or over what period of table grapes can be kept fresh. The grapes were stored under the above-mentioned carbon dioxide shielding gas envelope at temperatures around 0 ° C. After two months the grapes nevertheless began to ferment. The wine produced from them was lighter, fruitier and less tannic than the traditional mash fermentation.

• Oenology