You can make a white roux sauce in advance and keep it hot without a skin forming on the surface by stirring in just over half the recipe milk during preparation and bringing through to the I boil so sauce thickens. Then add rest of milk, ; pouring it over the surface. Keep on lowest heat and stir again only when you want to use the sauce.
Keep prepared sauces hot without scorching by setting the saucepan in a larger one of hot (not boiling) water so the base of the pan is away from direct heat.
More delicate egg-based hollandaise or bearnaise sauces can be held for a short time if you turn the sauce into a warmed jug and set in a saucepan of warm water away from the heat, to hold the correct temperature.
Sauces to be prepared and used later in a recipe â white sauce for mousse, curry or brown sauce for casseroles or tomato sauce for pasta â should be poured into a bowl, then covered with a circle of wetted greaseproof paper (wet side against the sauce) to prevent a skin forming as sauce cools. Refrigerate as soon as cold. Keep roux-based sauces and ragii sauce with meat no more than 24 hours.
Acid sauces such as Cumberland, apple, barbecue, cranberry and tomato can be made in advance and refrigerated for up to 48 hours. Soured cream sauces also keep for up to 48 hours.
Home-made mayonnaise will keep 3 weeks in the refrigerator. Once mayonnaise is mixed with other ingredients â herb mayonnaise, curry or seafood dressingâ the keeping time cuts to 1 week.