verjus or verjuice, the tart, apple-flavoured juice of unripe grapes, has many variations and many culinary uses, especially in dressings and sauces. It adds acidity to a dish but unlike vinegar does not clash with wine. Traditional in many countries of the world, it is made from underripe grapes cut during crop thinning or from second crop berries that are unripe at harvest. One method is to press the grapes then preserve the partially fermented but highly volatile juice with salt. Alternatively, the grapes may be boiled before pressing to kill the yeast and prevent fermentation but must then be used immediately or frozen. Most commercial producers gently press the grapes, cold settle and filter the juice before packaging, in which case sterile bottling is essential to prevent the verjus from fermenting.
