Inside the Berry: How Carbonic Maceration Works

This winemaking method triggers fermentation without yeast right under the grape skin. The process results in wines with a bright fruit aroma and a soft character. We explain how this technology works and why it is associated with more than just Beaujolais.

What is Carbonic Maceration

A technique that forces grapes to ferment from within without crushing the berries or oxygen contact.

The Magic of Intracellular Fermentation

Carbonic maceration is the process of fermenting whole, undamaged grape bunches in a sealed vessel filled with carbon dioxide. In the absence of oxygen, the berries switch to anaerobic metabolism. Inside each grape, its own enzymes are activated, starting to break down sugar into alcohol and carbon dioxide. The process occurs without yeast until the alcohol level inside the berry reaches about 2%, after which the skin bursts.

This method minimizes the extraction of tannins from the skins and seeds, as the must is not pressed at the initial stage. As a result, the wine is very soft, easy-drinking, with low astringency, while acquiring characteristic notes of ripe berries, banana, barberry, and bubblegum.

Four Conditions to Start the Process

Intact Bunches

The berries must remain whole on the stems to trigger internal metabolism.

Oxygen-Free Environment

The tank is sealed and filled with carbon dioxide to displace oxygen.

Intracellular Enzymes

Sugar breakdown is triggered by the grape's own enzymes, not yeast.

Temperature Control

The tank is kept warm at around 30–35 °C to accelerate fermentation inside the berries.

Semi-Carbonic Maceration: The Secret of Beaujolais

In practice, winemakers more often use semi-carbonic maceration (macération semi-carbonique) — the signature style of Beaujolais. With this technology, whole bunches are loaded into a tank, where they are pressed under their own weight.

The bottom layers of grapes are inevitably crushed by the weight of the top ones, and the released juice begins to ferment in the usual yeast-driven way. The carbon dioxide released during this process rises, fills the container, and naturally displaces oxygen. As a result, classic carbonic maceration is triggered inside the whole berries in the upper and middle layers of the tank.

This combination of two fermentation types allows Beaujolais winemakers to find a balance. Yeast fermentation of the juice at the bottom gives the wine structure, tannins, and ageing potential, while intracellular fermentation at the top saturates it with a vibrant palette of fresh fruit and floral aromas.

Semi-Carbonic Maceration: The Secret of Beaujolais

Geography of the Method: From France to Spain

Although the technology is strongly associated with Beaujolais, it is successfully used in other European wine regions.

Beaujolais and the Gamay Variety

In the French region of Beaujolais, the Gamay variety reveals its potential precisely due to semi-carbonic maceration. The method softens the variety's high natural acidity, turning it into juicy, food-friendly wines. From simple Beaujolais Nouveau to complex wines from the communal appellations of Morgon or Moulin-à-Vent, this technique leaves its recognizable fruity mark everywhere.

Rioja Alavesa and Young Tempranillo

In the Spanish region of Rioja Alavesa, the carbonic maceration method (maceración carbónica) has been used historically. Thanks to this technique, the local Tempranillo acquires a deep purple color, aromas of blueberry and licorice, and a soft taste without harsh tannins.

Italian Novello Wines

In Italy, the counterpart to young wine is the Novello category. In the Abruzzo region, winemakers use carbonic maceration for the Montepulciano variety. The law requires at least 40% of the grapes to undergo this process, guaranteeing the wine a light and juicy berry profile.

Want to experience this style in practice?

Try wines made using the carbonic maceration method to feel the difference yourself. In the Solo Wine catalog, you will find both classic examples from Beaujolais and juicy young wines from Spain. Discover new facets of familiar grape varieties.

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