Basic Custard

Ingredients

• 6–8 eggs
• 1 quart milk
• sugar
• 1 tbsp flour
• pinch salt
• small piece butter

Method

Custard is an egg and milk emulsion held together by gentle heat. The yolks carry fat and lecithin, which bind the milk proteins into a smooth suspension. Cook it too fast or too hot and the proteins seize, squeezing out whey. Cook it right and you get silk. The architecture matters: build the yolk base first, incorporate the whites for lift (if you want a baked custard), then marry it all with cold milk so the sudden temperature shock doesn't scramble anything before it hits the oven or pan.

Whisk the yolks in a bowl until they lighten and ribbon slightly — two to three minutes by hand. Sift the flour into the sugar to break any lumps, then beat this mixture into the yolks until pale and thick. This prevents lumps and aerates the yolks, which will trap steam later. Warm the milk to blood temperature (around 37°C), no hotter. A rolling boil is wrong — you'll cook the eggs before you've even poured. Stir the warm milk slowly into the egg mixture, whisking as you go. The gradual introduction prevents shock.

For baked custard, whip the egg whites to stiff peaks separately and fold them in gently — this is where you trap air for a lighter, soufflé-like texture. Strain the whole thing through fine muslin to catch any bits of cooked egg or shell, then pour into a buttered dish. Bake in a water bath (a bain-marie) at 160°C. The water insulates the custard, distributing heat evenly and keeping the temperature below boiling. You're done when the surface firms but the very centre still trembles slightly when you shake the dish — it will carry over and set as it cools. If you see browning or smell sulphur, you've gone too far.

For boiled custard, skip the whites and skip the oven. Pour into a bowl set over simmering water and stir constantly with a spatula, scraping the bottom and sides. This tempering technique — keeping the heat gentle and the mixture in motion — prevents the yolks from scrambling. You'll feel the custard thicken after eight to ten minutes. When a line drawn across the back of the coated spoon holds, it's done. Strain immediately into a cold bowl to arrest the cooking. Serve warm or chilled.