Making Red Wine

Preparing the Grapes

The freshly harvested grapes are used as soon as they arrive at the winery. While grapes can be crushed by stomping on them with your feet in a big vat, a more practical way is to use a machine which does the job, as well as removing the stems. The resulting mixture is called a Must.

The stems are usually removed since the tannins they contain can be overly harsh, and don't soften with age. However, if the winemaker decides that the wine will need some extra structure, he may choose to leave some of the stems in the Must. The Must is then pumped to a vat to be fermented and macerated.

Fermentation

A fermentation vat is made of either oak or stainless steel. Fermentation is usually started between 12 to 72 hours later, and together with maceration, can last between a week to a month. During the fermentation the yeast gradually digests the sugars from the grape juice, producing alcohol and carbon dioxide.

Temperature is very imortant during fermentation, higher temperatures mean more colour and tannin in the wine, lower temperatures give more fruit and bouquet. The optimum temperature for for fermentation is around 30 ˚C. If the temperature is too high, it can affect the taste of the wine due to the fruity aromas boiling off, as well as unwanted chemicals being produced by the yeast. If the temperature is too low, the fermentation will be slow or not happen at all.

The winemaker usually eliminates unwanted contaminants by using sulfur dioxide. Unfortunately, the sulfites which remain in the wine may cause a lot of discomfort to some wine drinkers.

Maceration

Maceration is the process of allowing the skins to impart colour and tannin to the wine, and can happen before, during or after fermentation.

Types of Maceration

Before fermentation, cold maceration is the period of time used to extract colour and flavour prior to the start of fermentation. This time period can be extended by chilling the macerating fruit to prevent fermentation.

Extended maceration is the extra time that the red wine is in contact with the skins after primary fermentation has completed.

Carbonic maceration is the fermentation of whole clusters of unbroken grapes in an atmosphere saturated with carbon dioxide, which prevents fermentation. This method is used to increase the fruitiness of a wine.

(From Wikipedia)

The Manta

The skins have a tendancy to float to the surface of the vat and form a 'cap'. This cap is called the Manta. It is important that the skins remain submerged in the must, since they allow maceration to take place. There are several methods of doing this, for example, pumping juice from the bottom of the vat and spraying it over the Manta, pushing down the Manta manually using poles, or using a wire mesh to hold the Manta below the level of the liquid. These methods are usually carried out twice a day.

When making lighter red wines the Manta is separated after a few days of contact, ending maceration. However, for fuller reds, contact can go on for a week to a month. This process only happens with making red wines, the process of making white wine doesn't use the grape skins in fermentation.

Separating the Skins and the Juice

After Fermentation and Maceration the skins are separated from the juice. The 'free run' juice or 'Vin de Goutte' runs out of the vat on opening the tap. The remaining contents are then pressed to produce 'press wine' or 'Vin de Presse'. These two parts go on to produce seperate wines. The best wine is made from the 'free run' juice, while 'press wine' is dark and very tannic.

Return to the Wine Guide Contents
A brief history of Wine | Growing Vines and Grapes | Harvesting | Making Red Wine | Making White Wine | Making Rosé Wine | Making Champagne | To Oak or not to Oak? | From Fermentation to Bottle