Vinegar

Whisk three parts oil with one part vinegar, a little mustard and a pinch of salt. Add the vinegar gradually and taste before tossing it with leaves, tomatoes or cooked vegetables.

Yes. After frying, take the pan off the heat briefly, add a small splash of vinegar and scrape up the browned bits; stir it into the sauce with stock or water so the sharpness does not dominate.

Simmer balsamic vinegar gently in a small pan for about 10–15 minutes, stirring now and then, until it coats a spoon. It thickens further as it cools, and is good drizzled over roasted vegetables, strawberries or grilled cheese.

Yes: cover sliced vegetables with a brine made from equal parts vinegar and water, plus salt and a little sugar, then chill in the fridge. Use vinegar labelled as having 5% acidity, and keep these quick pickles refrigerated rather than treating them as shelf-stable preserves.

Keep the bottle tightly closed in a cool, dark cupboard, away from the hob. Cloudiness or a soft, jelly-like sediment can form in some vinegars and is generally harmless; strain it out if you prefer.

Lemon juice gives a similar sharpness, though it tastes more citrusy; use it in the same way and add it gradually. For a milder dressing, try a little wine or verjuice, then balance the flavour with mustard or herbs.

Balsamic vinegar is usually sweeter and more concentrated, and some types are thick enough to drizzle over food; wine vinegar is sharper and more suited to dressings and marinades. Balsamic vinegar has 88 kcal per 100 g, compared with 25 kcal in wine vinegar.

Yeast first turns sugars in a liquid such as wine, cider or rice ferment into alcohol; bacteria then convert the alcohol into acetic acid. The starting liquid gives the vinegar much of its characteristic flavour.