All good wine growers select and process the different grape varieties separately. Eventually they are blended into the final wine, an art which been practised for centuries. The precise vinification processes vary between the different regions and Appellations and even each château leaves it's own mark on each vintage, so the following is a general guide to how are made.



At harvest time, the healthiest grape clusters are picked and loaded into a machine that de-stems and gently crushes the grapes to release the juice called "must."
Red: The must and skins are transferred into a fermentation vat which can be made of stainless steel or wood.
White: Sulphur dioxide is quickly added to the must to prevent oxidisation which would result in a less fruity wine, then the skins are removed from the must before it is transferred into a fermentation vat.


Natural yeast is present on grape skins, it gives the skin that cloudy look whilst on the vine. In the vat the natural grape sugar is converted into alcohol by the yeast (which is sometimes supplemented by the addition of special yeast strains).
Red: Alcoholic fermentation takes place over a period of 5 to 10 days. Most red wines are fermented to complete dryness, with little or no residual sugar remaining.
White: Alcoholic fermentation for white wine lasts longer than for red — 12 to 15 days — and at cooler temperatures so that more of the juices' natural aromas are retained. Dry white wines are made by allowing all of the grape sugar to turn into alcohol.


Red: Some producers leave the juices to soak with the skins, pulp, pips and dead yeast cells (together called "marc") for up to 18 days during which time the alcohol extracts pigment, tannins, and favours from the marc.



Red: Fermented grape juice (called free-run wine) is separated from the marc and the marc pressed to extract any remaining wine. This wine, called 'vin de presse', has highly concentrated favours, tannins, and colours and may be blended back into the wine to achieve the desired style and favour.


This sometimes is performed most on red wine production rather than white. It sometimes occurs naturally but can be induced by the winemaker. 'Malolactic' fermentation as it is sometimes called converts malic acid to lactic acid which lowers a wine's acidity and makes it softer and more pleasant to drink. In white wine production, Malolactic fermentation risks lowering the wine's acidity too much, so it must be accomplished with great skill and subtlety.


Next the wine is 'racked', which separates the clear wine from any remaining particles from the marc. An alternate way to clarify a wine is to introduce a substance called a "fining agent" which causes solid particles to fall to the bottom of the container for removal. Egg whites are commonly used as a fining agent. Filtration and the use of a centrifuge are other clarification methods.


The winemaker combines wines made from different grape varieties and vats to create the desired bouquet, style and flavour of the wine.


Red: Wine may be aged for up to two years in oak barrels which impart structure, additional tannin and favour. Finally, the wine is bottled and stored in cellars for further ageing, or sold on.
White: Ageing is much shorter for white wines than for reds. Some may be aged for up to one year in oak barrels which give the wine additional structure and favour. However, most dry white wines are bottled within a year after harvest.




Most of the grapes used for sweet white wines are left on the vine until 'noble rot' appears. They are not 'rotten' as such, but a fungus called 'Botrytis cinera' causes water to evaporate from the grape, in a similar way to the production of raisins shrivel the grape. The resultant shrivelled grape has a very high concentration. Grapes are usually picked over a longer period of time than red grapes, only the ripest and sweetest being picked on each harvest.


Because the grape has such a high density of sugar the natural yeast can only turn a proportion of the sugar into alcohol before it dies, stopping fermentation and leaving upto 12% residual (unfermented) sugar in the finished wine.


After blending, sweet wines are usually aged for up to three years in oak barrels to increase richness before bottling and distribution.