||It has been suggested that Creme anglaise be merged into this article. (Discuss) Proposed since March 2013.|
A bowl of crème anglaise custard, dusted with nutmeg
|Main ingredient(s)||Milk or cream, egg yolks, sugar, vanilla|
Custard is a variety of culinary preparations based on a cooked mixture of milk or cream and egg yolk. 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 (crème pâtissière) used to fill éclairs. Most common custards are used as desserts or dessert sauces and typically include sugar and vanilla. Custard bases may also be used for quiches and other savory foods. Sometimes flour, corn starch, or gelatin is added as in pastry cream or crème pâtissière.
Custard is usually cooked in a double boiler (bain-marie), or heated very gently in a saucepan on a stove, though custard can also be steamed, baked in the oven with or without a water bath, or even cooked in a pressure cooker. Custard preparation is a delicate operation, because a temperature increase of 5–10 °F (3-6 °C) leads to overcooking and curdling. Generally, a fully cooked custard should not exceed 80 °C; it begins setting at 70 °C. A water bath slows heat transfer and makes it easier to remove the custard from the oven before it curdles.
Mixtures of milk and eggs thickened by heat have long been part of European cuisine. Custards baked in pastry (custard tarts) were very popular in the Middle Ages, and are the origin of the English word 'custard': the French term 'croustade' originally referred to the crust of a tart, and is derived from the Italian word crostata, and ultimately the Latin crustāre.
Examples include Crustardes of flessh and Crustade, in The Forme of Cury. These recipes include solid ingredients such as meat, fish, and fruit bound by the custard. Stirred custards cooked in pots are also found under the names 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, [kʁɛm mule]) refers only to an egg-thickened custard.[circular definition]
When starch is added, the result is called pastry cream (French: crème pâtissière, pronounced: [kʁɛm patisjɛːʁ]) or confectioners' custard, 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 mille-feuille (or Napoleons) and filled tarts. It is also used in Italian pastry and sometimes in Boston cream pie. Although egg thickens the custard, the effect is minimal, with the majority of thickening resulting from starch. Corn flour or flour thicken at 100 °C and as such many recipes instruct the pastry cream to be boiled. In a traditional custard such as a crème anglaise, where egg is used alone as a thickener, boiling results in the over cooking and subsequent 'curdling' of the custard; however, in a pastry cream, starch prevents this. Once cooled, the amount of starch in pastry cream 'sets' the cream and requires it to be beaten or whipped before use.
When gelatin is added, it is known as crème anglaise collée ([kʁɛm ɑ̃ɡlɛz kɔle]). When starch is used alone as a thickener (without eggs), the result is a blancmange. In the United Kingdom, custard often refers to a dessert thickened from cornflour (cornstarch) rather than eggs; see custard powder.
After the custard has thickened, it may be mixed with other ingredients: mixed with stiffly beaten egg whites and gelatin, it is chiboust cream; mixed with whipped cream, it is crème légère, [kʁɛm leʒɛːʁ].
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, stew or broth. Chawanmushi is a Japanese savoury custard, cooked and served in a small bowl or on a saucer.
Recipes involving sweet custard are listed in the custard dessert category, and include:
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 imitation custard powder (starch) in water, with the proper proportions, has the opposite rheological property: it is negative thixotropic, or dilatant, allowing the demonstration of "walking on custard"; see the physical properties of custard powder.
|Wikimedia Commons has media related to: custards|
|Look up custard in Wiktionary, the free dictionary.|
|Wikibooks Cookbook has a recipe/module on|
- Barham, Peter (2001). The science of cooking. Berlin: Springer. p. 126. ISBN 3-540-67466-7.
- McGee, Harold (1984). On Food and Cooking. p. 71. ISBN 0-684-18132-0.
- Oxford Companion to Food, s.v. 'custard'
- Skeat, Walter William (1911). A concise etymological dictionary of the English language. Oxford: American Book Company. LCCN 11035890. OL 16525337M. Page 125.
- Hieatt, Constance, and Sharon Butler. Curye on Inglysch: English culinary manuscripts of the fourteenth century (including the forme of cury). London, EETS SS 8, 1985.
- Austin, Thomas, ed. Two Fifteenth-Century Cookery Books. London, EETS OS 91, 1888, repr. 1964; referring to Harleian MSS 279 and 4016.
- Karla Longrée, Sharie Beaver, Paul Buck, Joseph E. Nowrey, "Viscous Behavior of Custard Systems", Journal of agricultural and food chemistry 14:6:653 (1966), pubs.acs.org