Custard is a range of preparations based on milk and eggs. Most commonly, custard refers to a dessert or dessert sauce, but custard bases are also used for quiches and other savory 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 is also added.

Custard is usually cooked in a double boiler (bain-marie), microwave or heated very gently in a saucepan on a stove,

though custard can also be steamed, baked in the oven with or without a hot water bath, or even cooked in a pressure cooker. Cooking until it is set without cooking it so much that it curdles is a delicate operation, because only 5–10 °F (3-6 °C) separate the two. A water bath slows heat transfer and makes it easier to remove the custard from the oven before it curdles.

Depending on how much egg or thickener is used, custard may vary in consistency from a thin pouring sauce (crème anglaise), to a thick pastry cream used to fill éclairs.

Custard is an important part of dessert recipes from many countries.

History

Custard was known in English cuisine at least as early as the fourteenth century. Recipes for custards baked in pastry (custard tarts) appear, under titles such as Crustardes of flessh and Crustade, in The Forme of Cury and Harleian MSS 279 and 4016.These recipes include solid ingredients such as meat, fish, and fruit, which are baked in the custard. Meanwhile, recipes for stirred custards cooked in pots appear in the same Harleian MSS as Creme Boylede and Creme boiled.

Custard variations

While 'custard' may refer to a wide variety of thickened dishes, technically (and in French cookery) the word custard (crème or more precisely crème moulée) refers only to an egg-thickened custard.

When starch is added, the result is called pastry cream (crème pâtissière), which is made with a combination of milk or cream, egg yolks, fine sugar, flour or some other starch, and usually a flavoring such as vanilla, chocolate, or lemon. Crème pâtissière is a key ingredient in many French desserts including millefeuille (or Napoleons) and filled tarts. It also used in Italian pastry and sometimes in Boston cream pie.

When gelatine is added, the result is crème anglaise collée.
When Italian Meringue plus gelatin is added, the result is "chiboust".
When whipped heavy cream is added, the result is "creme mousseline".
When starch is used alone as a thickener (without eggs), the result is referred to as a blancmange.
In the United Kingdom, 'custard' often refers to a dessert made from cornflour rather than eggs;

Savory custards

Not all custards are sweet. A quiche is a savory custard tart. Some kinds of timbale or vegetable loaf are made of a custard base mixed with chopped savory 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:

• Bavarian cream
• Clafoutis
• Cream pie
• Crème brûlée
• Crème caramel
• Custard tart
• English trifle
• Egg tart
• Flan
• Frozen custard
• Galaktoboureko
• Kremna rezina
• Pastel de nata
• Pumpkin pie
• Taiyaki
• Vanilla slice
• Vla
• Kremsnite
• Zagrebacke Kremsnite
• Samoborske Kremsnite
• Zabaglione
• Floating island (dessert)

Physical properties

Cooked (set) custard is a weak gel, 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.

A suspension of uncooked custard powder or starch 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. 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 called "walking on custard." A similar exhibition was performed on the Discovery Channel series MythBusters, in which co-host Adam Savage traversed a tank filled with water and cornstarch.