Sauce questions, answered.

Three reliable ways: a cornstarch slurry (1 tablespoon cornstarch to 1 tablespoon cold water, stirred in off the boil), a roux (equal butter and flour cooked first), or simply reducing it by simmering uncovered until it coats a spoon. We state which method each recipe uses and the exact ratio.

For a cream or cheese sauce that went grainy, pull it off the heat and whisk in a splash of cold cream or a little more cheese off the boil. For an emulsion like hollandaise, whisk a teaspoon of warm water, or start a fresh yolk and dribble the broken sauce back in. Most splits are from too much heat.

Too thin: simmer it down a few minutes, or add a little slurry. Too thick: loosen it with a splash of the cooking liquid, stock, milk or water, a tablespoon at a time. We give the target consistency on every recipe so you know what you're aiming for.

Add the fat slowly while whisking hard, and keep the temperature gentle. For aioli or mayo, drizzle the oil in almost drop by drop at first. For butter sauces, keep the pan just warm, never boiling. An emulsion breaks from adding fat too fast or from heat that's too high.

Two reasons: the heat was too high, or the cheese was pre-shredded (the anti-caking starch makes it clump). Melt freshly grated cheese off the boil, a handful at a time, into a warm — not boiling — base. A teaspoon of cornstarch tossed with the cheese also helps it stay smooth.

Reducing means simmering a sauce uncovered so water evaporates and it thickens and concentrates in flavor. Keep it at a gentle simmer, not a hard boil, and stir so the bottom doesn't scorch. Most sauces reduce by about a third to coat a spoon.

Most cooked tomato, BBQ and Asian sauces keep 1 to 2 weeks airtight in the fridge. Dairy-based sauces (alfredo, cheese, hollandaise) are best within 3 to 4 days. Mayo-based dips keep about a week. We state the fridge life on every recipe.

Tomato, BBQ, pesto and most reduced sauces freeze well for up to three months. Cream, cheese and egg-emulsion sauces tend to split when thawed, so make those fresh. We note which sauces freeze on each recipe.

A rough guide: cream and alfredo with long pasta, marinara with everything, BBQ and buffalo with chicken and pork, teriyaki and peanut with stir-fries and noodles, cheese with vegetables and nachos, and dessert sauces over ice cream and cake. Each recipe lists what we pair it with.