Greek yogurt

It is made by fermenting milk with yogurt cultures, then straining away some of the whey. That gives it its thick texture; Greek-style yogurt is often thickened by other methods instead.

Yes: take the pan off the heat and stir in the yogurt at the end. For a hot sauce or soup, first mix a spoonful of the hot liquid into the yogurt, then stir the warmed yogurt mixture back into the pan without boiling it.

Keep it covered in the fridge and use a clean spoon each time. Follow the use-by date and discard it if it develops mould, an unusual smell or a change in texture that is not just whey separating.

It works with berries, chopped fruit, honey or toasted nuts for breakfast, and with cucumber, garlic, lemon and dill as a dip for vegetables or grilled food. It is also the base of tzatziki.

For dips and toppings, use thick plain yogurt; if it is runny, drain it through a clean cloth in the fridge. Sour cream works in many savoury recipes, though it gives a richer, less tangy result.

Greek yogurt is traditionally thickened by straining out whey. Greek-style yogurt may instead be thickened with ingredients such as milk proteins or starch, so check the ingredients if you want the strained kind.

You can freeze it in a sealed container, but it may turn grainy or separate when thawed. Stir it well and use it in smoothies, baking or cooking rather than expecting its original creamy texture.