Acid

Acidity plays a most important part in the quality of a finished wine, and lack of acid will result in a poor fermentation, and the wine will probably have a medicinal flavour. It is a very good thing to taste the must just before the yeast is put in. It should taste slightly of a lemon drink if the balance is right. Of course, for a beginner, this balance is difficult to assess, but if flavours can be memorized it will help enormously.

Acidity, tannin and the degree of sweetness should be in balance in any good wine. A table wine, because it is usually less sweet, will have less acid and tannin than a heavier dessert wine. The majority of recipes will suggest the addition of one or two lemons (or the equivalent acid in powder form). This will vary, of course, according to the nature of the main ingredient, e.g. redcurrants, raspberries and gooseberries are already high in acid, and will not need any addition, whereas flowers, leaves, vegetables and grain will be deficient, and will need the addition in full. Although many recipes suggest that lemons should be used to provide the acid content of a wine, this is by no means the ideal for two reasons. First, it is not known how much citric acid there is in a lemon which may be large and juicy, or small and dry. Second, citric acid, although producing a good ferment is not the best of acids for bouquet. For the best wines, try acid in powder form (the equivalent of one lemon to be taken as ¼oz/8g) and it is even suggested that a blend of 50% tartaric, 30% malic and 20% citric will give the best results. If the acid content of a must is too high, even without the addition of acid, it can be reduced in one of three ways: (1) the addition of precipitated chalk, but it is not advisable to use much above ½oz/15g as it might leave a chalky flavour in the wine; (2) potassium carbonate can be used in small quantities if made up into a solution of 8oz/225g to 1 pint/500ml water, but only add it at the rate of ½fl.oz/12.5ml at a time; (3) reducing the acid content by the addition of water, but for this to be successful, make sure that the body of the wine will allow the dilution, otherwise a watery, weak liquid will result.