It is usually a sour, acidic juice extracted from unripened grapes and therefore is often produced by wine makers, especially in France, Australia and Spain. In Britain verjuice used to be made with crab apples.

Although verjuice can be found in some supermarkets, it is still not widely available. Use lemon juice or sherry as a substitute - it won't be quite the same but will bring your recipe some of the necessary souring quality verjuice provides.

Use verjuice any place you would use white wine or dry sherry in cooking, for example sauces, stews and risottos, and especially for deglazing.

A traditional ingredient of made mustards, it is good for fish stock or court bouillon and makes delicious fruit compotes.

Once opened, store well-sealed in the fridge and aim to use within two weeks.