The first operation performed on grapes after they are removed from their storage is to de-stem them, which is the process of removing the grape from the shoots to which they are attached.
As soon as all the grapes in the batch are de-stemmed, they are placed into the wine press where they are compressed into a paste which in turn releases the must (the juice of the fruit). The resulting paste (or pomace) and must combination then spend time together in a cask and it is the length of time that the mixture sits with the must in contact with the grape skin and pulp that determines the character of the finished wine.
When the winemaker determines the right amount of time has passed, the juice is drawn off and yeast added to begin the fermentation process with the remaining pomace, in many cases, being returned to the vineyard to be used as a fertilizer.
Once the colour and sugar content are correct the cask valve is opened and the first juice, which is the best quality wine, is then transferred into other containers where the fermentation process is finalized.
‘Pressed wines’, which are full of tannin, are made from the leftover solids. They have a strong colour and are generally mixed with the first juice in many different ways to create wines of different strengths and flavours.
When the fermentation process is complete, the wine is either bottled straight away, or left to age.
When making white wine it is important not to damage the grapes, so they are poured into the receiving bins as quickly as possible. Once they are all in the receiving bin, the grapes are then transferred to the press where the must is separated from the skins and other solids.
At this stage the solids are disregarded and the remaining must is slightly refrigerated before being transferred into a stainless steel vat where it is allowed to ferment. Care is taken to maintain the temperature during fermenting which preserves the delicate aromas of the finished wine.
Once the fermentation process is complete, the resultant wine is decanted taking care to avoid the sediment which collects at the bottom of the vat. After decanting, the wine is bottled and ready to be sold, and is best drunk within two years.
Sweet Dessert Wines
Dessert wines are produced in one of two ways. In the first method, Botrytis Cinera, a fungus which grows very quickly, is used. This transforms the fruit and changes the colour and also alters the acid components and sugar levels. The second method is to interrupt the fermentation process by adding alcohol. This method creates a strong, sweet wine where the grape is the major flavour.
Grapes used for sweet wines are of the white Moscatel and Garnacha varieties which, along with the production process, leave the wine with a mushroom type smell as the bottle is opened.