When is custard set

Technically, a custard is any liquid thickened by eggs, and in most cases that liquid is cream or milk. Knowing the scientific principles behind them—plus a few key cooking tips and tricks—can help you get these luscious desserts right every time. Slideshow: Get the recipes for more than a dozen scrumptious custard desserts. Pure or basic custards are thickened and set by eggs alone. These are the most delicate custards; they require careful attention during cooking, which is usually done in the even heat of a water bath, as they can quickly go from undercooked to broken and curdled.

Starch-thickened custards contain ingredients such as flour or cornstarch for added thickening power. These starches give custards more body, making them sturdy enough to endure cooking with direct heat. Gelatin-set custards have an alluring richness from the structural boost that only gelatin can provide.

What sets them apart? These delicate custards are thickened only with eggs. When heated, the egg proteins slowly unwind from a coil-like shape and elongate. The proteins can then easily catch onto one another to form a gel, which thickens the mixture.

If you freeze this custard sauce, you get ice cream. To prevent overcooking, basic custards are usually cooked over a double boiler or baked in a water bath. Remove baked custards from the oven when they have just a slight wobble in the center when nudged; residual heat will continue to cook them until fully set. The addition of wheat flour or corn or potato starch gives these custards a full-bodied texture, and the extra starch molecules slow protein coagulation, making them more resistant—though not immune—to overcooking and curdling.

Delicious examples: Starch-thickened custards take many forms, from pudding to pastry cream and cheesecake. Puddings contain just enough thickener to give them body but not enough to make them stiff. Pastry cream is thicker it contains more starch , which makes it a sturdy foundation for a fruit tart or a cream pie. Clafoutis, a classic French custard, is on the far side of the starch-thickened custard continuum, since it contains a relatively high ratio of starch to liquid.

Getting them right: starch-thickened custards must reach a simmer to ensure that the amylase enzyme in the egg yolks has been denatured, or rendered inactive, by heat. This is especially true of stirred custards like puddings and pastry cream, which are easy to under-cook on the stove-top. An undercooked custard may initially appear thick but will slowly turn to soup as the amylase enzyme attacks the starch and breaks the custard down.

A good guideline is to cook for 1 to 2 minutes after bubbles appear in the custard, stirring constantly. If you overcook a starch-thickened custard, you can use a fine strainer to strain out any bits of egg. Like eggs, gelatin contains proteins that bind liquid. Sometimes oil-based cakes or quickbreads produce a clean tester before the batter is fully cooked.

This is why I also recommend using your finger to tap lightly in the center of the cake. It should feel firm and lightly springy to the touch. Another way to tell is color and surface texture. For white or yellow cakes , the surface should be uniformly golden brown all the way across, not just around the edges. Raw batter is shiny because of the butter or oil content; cooked batter is matte.

This can be tricky because the cookie will seem under-baked on the cookie sheet but will firm up as it cools. To avoid under-baking to the point of rawness which is actually not as desirable as it sounds , look for the center to have lost its sheen and taken on a golden color, but unlike the edge it will yield to a light poke. Bake in oven until the custards are just set.

The secret to cooking stirred custard is to cook it in a large saucepan over medium-low heat. Stir constantly with a wooden spoon, until the custard thickens and coats the back of the spoon. Draw a finger across the back of the spoon and if it leaves a trail, your custard is ready. After cooking stirred custard, strain through a fine sieve into a jug. This removes any bits of egg that may not have been properly combined, and ensures that the custard is as smooth as possible.

Straining is an important part of making baked custard, too. Strain the egg mixture before cooking to ensure your baked custard is smooth. Log In Sign Up. How to make perfect custard.