Probably the oldest winemaking technique, it existed in all production areas until the late 19th century when the French “Médoc method” of winemaking and ageing took over; the latter uses stemming, which is to say separating the fruit from the stalk or stem of the grape cluster.
Carbonic maceration, also known as intracellular maceration, is a technique for making friendlier, fresher and fruitier wines. In a not-too-distant past, Rioja crianza and even reserva wines may have had a high percentage of maceration running through their veins, given that the bottling firms usually bought wine from cosecheros.
The fermentation takes place in closed vats using whole bunches, without stemming or pressing, aside from a light “treading” to start off the work of the micro-organisms that exist within the skin of the grape.
In these conditions, the atmosphere is saturated with carbon dioxide and the intracellular fermentation begins inside each single, intact grape. In the absence of oxygen, fermentation takes place by means of enzymes and not yeasts, which can only grow if they breathe the oxygen in the environment. This method results in wines with a characteristic delicate fermentation aroma which accompanies and brings out the floral, fruity nature of the wine.
Although it may seem simple, it is not easy to produce such wines. Those of higher quality require a meticulous level of cleanliness, raw material in a perfect state and total dedication to its care by the winemaker.