Custard
Custard is a range of preparations based on milk and eggs, thickened with heat. Most commonly, it refers to a dessert or dessert sauce, but custard bases are also used for quiches and other savoury foods. As a dessert, it is made from a combination of milk or cream, egg yolks, sugar, and vanilla. Sometimes flour, corn starch, or gelatin are also added. In French cookery, custard—called simply "crème" or more precisely "crème moulée"—is never thickened in this way: when starch is added, it is pastry cream crème pâtissière; when gelatin is added, it is crème anglaise collée.
Depending on how much egg or thickener is used, custard may vary in consistency from a thin pouring sauce (crème anglaise), to a thick blancmange like that used for vanilla slice or the pastry cream used to fill éclairs.
Custard is usually cooked in a double boiler (bain-marie) or heated very gently on the stove in a saucepan, though custard can also be steamed, baked in the oven with or without a hot water bath, or even cooked in a pressure cooker. The trick to getting custard instead of sweetened eggs is to add heated milk to the eggs, not to add eggs directly into the pan on the stove. Cooking until it is set without cooking it so much that it curdles is a delicate operation, because only 5-10°F (3-5°C) separate the two. A water bath slows heat transfer and makes it easier to remove the custard from the oven before it curdles.[1]
Custard is an important part of dessert recipes from many countries, including the United Kingdom, France, Portugal, Spain, Italy, Australia, South Africa and Argentina.
Instant and ready-made 'custards' are also marketed, though they are not true custards if they are not thickened with egg. See Bird's Custard, for instance. In the United Kingdom, school custard is a common name for the 'custard' (usually made from cornflour) served for pudding at schools. Its poor quality and thick consistency are often the source of jokes. Pink school custard is made by combining Angel Delight (strawberry) with custard mix, generally starch based packet custard. [citation needed]
Savoury custards
Not all custards are sweet. A Quiche is a savoury custard tart. Some kinds of timbale or vegetable loaf are made of a custard base mixed with chopped savoury ingredients. Custard royale is a thick custard cut into decorative shapes and used to garnish soup or broth. Chawanmushi is a Japanese savory custard, cooked and served in a small bowl or on a saucer.
Uses
Recipes involving sweet custard are listed in the custard dessert category, and include:
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Physical properties
Cooked (set) custard is a weak gel which is viscous and thixotropic; while it does become easier to stir the more it is manipulated, it does not, unlike many other thixotropic liquids, recover its lost viscosity over time.[2]
A suspension of uncooked imitation custard powder (actually, any starch will do) mixed with water in the right proportions has the opposite rheological property: it is negative thixotropic, or dilatant, which is to say that it becomes more viscous when under pressure. It is often used in science demonstrations of non-Newtonian liquids: see Oobleck. The British popular-science program Brainiac: Science Abuse demonstrated dilatancy dramatically by filling a swimming pool with this mixture and having presenter Jon Tickle walk across it; this was misleadingly called "walking on custard".
References
