Custard

{{Short description|Semi-solid cooked mixture of milk and egg}} {{About|egg-thickened custards}} {{pp-semi-indef|small=yes}} {{Infobox food | name = Custard | image = Custard.jpg | caption = A bowl of {{lang|fr|crème anglaise}} custard, dusted with nutmeg | alternate_name = | country = | region = | creator = | course = Dessert | type = | served = | main_ingredient = Milk or cream, egg yolks, sugar, vanilla | variations = | calories = | other = }}

'''Custard''' is a variety of culinary preparations based on sweetened milk, cheese, or cream cooked with egg or egg yolk to thicken it, and sometimes also flour, corn starch, or gelatin. Depending on the recipe, custard may vary in consistency from a thin pouring sauce ({{lang|fr|crème anglaise}}) to the thick '''pastry cream''' ('''{{lang|fr|crème pâtissière}}''') used to fill éclairs. The most common custards are used in custard desserts or dessert sauces and typically include sugar and vanilla; however, savory custards are also found, e.g., in quiche.

==Preparation== Custard is usually cooked in a double boiler ({{lang|fr|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 {{convert|3|–|6|C-change}} leads to overcooking and curdling. Generally, a fully cooked custard should not exceed {{convert|80|°C|°F|abbr=on}}; it begins setting at {{convert|70|°C|°F|abbr=on}}.<ref>{{Cite book |last=Barham |first=Peter |url=https://archive.org/details/isbn_9783540674665/page/126 |title=The science of cooking |publisher=Springer |year=2001 |isbn=978-3-540-67466-5 |location=Berlin |page=[https://archive.org/details/isbn_9783540674665/page/126 126] |url-access=registration}}</ref> A {{lang|fr|bain marie}} water bath slows heat transfer and makes it easier to remove the custard from the oven before it curdles.<ref>{{Cite book |last=McGee |first=Harold |url=https://archive.org/details/onfoodcookingsci0000mcge |title=On Food and Cooking |year=1984 |isbn=978-0-684-18132-5 |page=[https://archive.org/details/onfoodcookingsci0000mcge/page/71 71] |publisher=Scribner |url-access=registration}}</ref> Adding a small amount of cornflour (known in Canada and the US as 'corn starch') to the egg-sugar mixture stabilises the resulting custard, allowing it to be cooked in a single pan as well as in a double-boiler. A {{lang|fr|sous-vide}} water bath may be used to precisely control temperature.

== Variations == {{More citations needed|section|date=July 2024}} right|thumb|A formal custard preparation, garnished with raspberries

While custard may refer to a wide variety of thickened dishes, technically (and in French cookery) the word ''custard'' ({{lang|fr|crème}} or more precisely {{lang|fr|crème moulée}}<!-- we are NOT talking about crème anglaise here, which is a thinner pouring custard used as a sauce -->, {{IPA|fr|kʁɛm mule|}}) refers only to an egg-thickened custard.

When starch is added, the result is called 'pastry cream' ({{langx|fr|crème pâtissière}}, {{IPA|fr|kʁɛm pɑtisjɛːʁ|pron}}) 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. {{lang|fr|Crème pâtissière}} is a key ingredient in many French desserts, including {{lang|fr|mille-feuille}} (or Napoleons) and filed tarts. It is also used in Italian pastry and sometimes in Boston cream pie. The starch prevents over-cooking the eggs, and sets the cream (usually requiring it to be beaten or whipped before use).thumb|Pastry cream[[File:Trifle-(cream-layer)-profile.jpg|right|thumb|Layers of a trifle showing the custard in between cake, fruit and whipped cream]]When gelatin is added, it is known as {{lang|fr|crème anglaise collée}} ({{IPA|fr|kʁɛm ɑ̃ɡlɛz kɔle|}}).

In the United Kingdom, custard has various traditional recipes some thickened principally with cornflour (cornstarch) rather than the egg component, others involving regular flour; see custard powder.

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. In German, it is known as {{lang|de|Eierstich}} and is used as a garnish in German wedding soup ({{lang|de|Hochzeitssuppe}}).<ref name="mcgavin_eierstich">{{Cite web |last=McGavin |first=Jennifer |title=Easy Eierstich Recipe- Royale as a Soup Garnish |url=http://germanfood.about.com/od/soupsandstews/r/eierstich-recipe.htm |url-status=dead |archive-url=https://web.archive.org/web/20161220094457/http://germanfood.about.com/od/soupsandstews/r/eierstich-recipe.htm |archive-date=20 December 2016 |access-date=4 November 2013 |website=About.com}}</ref> {{lang|ja-Latn|Chawanmushi}} is a Japanese savoury custard, steamed and served in a small bowl or on a saucer. Chinese steamed egg is a similar but larger savoury egg dish. {{lang|el-Latn|Bougatsa}} is a Greek breakfast pastry whose sweet version consists of semolina custard filling between layers of phyllo. In Peru, {{lang|es|leche asada}} ('baked milk') is custard baked in individual molds.<ref name="Elichondo1997">{{Cite book |first=Margarita |last=Elichondo |url=https://books.google.com/books?id=LV_33krxpx8C&pg=PA207 |title=La comida criolla: memorias y recetas |publisher=Ediciones Del Sol |year=1997 |isbn=978-950-9413-76-4 |page=207}}</ref> It is considered a restaurant dish.<ref name="CuadraEscardo2013">{{Cite book |last1=Morena |first1=Cuadra |url=https://books.google.com/books?id=gx7sDQAAQBAJ&pg=PT420 |title=The Everything Peruvian Cookbook: Includes Conchitas a la Parmesana, Chicken Empanadas, Arroz con Mariscos, Classic Fish Cebiche, Tres Leches Cake and hundreds more! |last2=Morena |first2=Escardo |date=18 January 2013 |publisher=Adams Media |isbn=978-1-4405-5678-4 |page=420}}</ref><!-- Crème légère is not mentioned by either Beck et al. nor Gisslen, but since it's mentioned in a previous section it's included here for completeness -->

== Uses == {{see also|List of custard desserts}} Recipes involving sweet custard are listed in the custard dessert category, and include:

{{Div col|colwidth=15em}} * Banana custard * Bavarian cream * {{lang|de|Bienenstich}} * Boston cream pie * {{lang|el-Latn|Bougatsa}} * Chiboust cream * Cream pie * {{lang|fr|Crème brûlée}} * {{lang|fr|Crème caramel}} * {{lang|de|Cremeschnitte}} * Custard tart * Danish pastry * Egg tart * Eggnog * English trifle * Flan * Floating island * Frangipane, with almonds * Frozen custard * Fruit salad * {{lang|el-Latn|Galaktoboureko}} * Manchester tart * {{lang|fa-Latn|Muhallebi}} * {{lang|es|Natillas}} * {{lang|pt|Pastel de nata}} * Pudding * {{lang|ja-Latn|Taiyaki}} * Vanilla slice * {{lang|nl|Vla}} * {{lang|it|Zabaione}} {{Div col end}}

== History == right|thumb|Custard tarts

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 {{lang|fr|croustade}} originally referred to the crust of a tart,<ref>{{Cite book |last=Davidson |first=Alan |editor1-first=Tom |editor1-last=Jaine |url=http://dx.doi.org/10.1093/acref/9780192806819.001.0001 |title=The Oxford Companion to Food |date=2006-01-01 |doi=10.1093/acref/9780192806819.001.0001|isbn=978-0-19-280681-9 }}</ref> and is derived from the Italian word {{lang|it|crostata}}, and ultimately the Latin {{Lang|la|crustāre}}.<ref>{{Cite book |last=Skeat |first=Walter William |url=https://archive.org/stream/cu31924008779690#page/n145/mode/2up |title=A concise etymological dictionary of the English language |publisher=American Book Company |year=1911 |location=Oxford |lccn=11035890 |ol=16525337M |ref=Skeat}} Page 125.</ref>

Examples include ''Crustardes of flessh'' and ''Crustade'', in the 14th century English collection ''The Forme of Cury''. These recipes include solid ingredients such as meat, fish, and fruit bound by the custard.<ref>{{Cite book |last1=Hieatt |first1=Constance |title=Curye on Inglysch: English culinary manuscripts of the fourteenth century (including the forme of cury) <!--London, EETS SS 8, 1985--> |last2=Butler |first2=Sharon}}</ref><ref name="AustinT">{{Cite book |title=Two Fifteenth-Century Cookery Books <!--London, EETS OS 91, 1888--> |date=1964 <!--Harleian MSS 279 and 4016--> |editor-last=Austin |editor-first=Thomas}}</ref> Stirred custards cooked in pots are also found under the names ''Creme Boylede'' and ''Creme boiled''.<ref name="AustinT" /> Some custards especially in the Elizabethan era used marigold (''calendula'') to give the custard color.<ref>{{Cite book |last=DeBaggio |first=Thomas |url=https://books.google.com/books?id=7_KPgxEglHAC&q=calendula+colored+custard+marigold&pg=PA183 |title=The Encyclopedia of Herbs: A Comprehensive Reference to Herbs of Flavor and Fragrance |date=September 2009 |publisher=Timber Press |isbn=9781604691344}} Page 183.</ref><ref name="rodale">{{Cite book |url=https://books.google.com/books?id=htGD3Y7WNxwC |title=Rodale's Illustrated Encyclopedia of Herbs|isbn=9780875969640|last1=Kowalchik|first1=Claire|last2=Hylton|first2=William H.|date=15 January 1998|publisher=Rodale }}</ref>

In modern times, the name 'custard' is sometimes applied to starch-thickened preparations like blancmange and Bird's Custard powder.

== Chemistry == Stirred custard is thickened by coagulation of egg protein, while the same gives baked custard its gel structure. The type of milk used also impacts the result. Most important to a successfully stirred custard is to avoid excessive heat that will cause over-coagulation and syneresis that will result in a curdled custard.<ref>{{Cite book |last=Penfield |first=Marjorie P. |url=https://books.google.com/books?id=rlpRi4urAMkC&q=how+does+custard+thicken&pg=PA144 |page=144 |title=Experimental Food Science |date=2 December 2012 |publisher=Academic Press |isbn=9780323140041 |access-date=4 November 2013 }}</ref>

Eggs contain the proteins necessary for the gel structure to form, and emulsifiers to maintain the structure. Egg yolk also contains enzymes like amylase, which can break down added starch.<ref name=":0" /> This enzyme activity contributes to the overall thinning of custard in the mouth. Egg yolk lecithin also helps to maintain the milk-egg interface. The proteins in egg whites are set at {{convert|60|–|80|C|F}}.<ref>{{Cite journal |last1=Kovacs-Nolan |first1=Jennifer |last2=Phillips |first2=Marshall |last3=Mine |first3=Yoshinori |date=2005-11-01 |title=Advances in the Value of Eggs and Egg Components for Human Health |journal=Journal of Agricultural and Food Chemistry |volume=53 |issue=22 |pages=8421–8431 |doi=10.1021/jf050964f |issn=0021-8561 |pmid=16248532}}</ref>

Starch is sometimes added to custard to prevent premature curdling. The starch acts as a heat buffer in the mixture: as they hydrate, they absorb heat and help maintain a constant rate of heat transfer. Starches also make for a smoother texture and thicker mouth feel.<ref name=":0">{{Cite book |last=McGee |first=Harold |title=On Food and Cooking |year=2004 |isbn=978-0-684-18132-5 |page=71 |publisher=Scribner }}</ref>

If the mixture pH is 9 or higher, the gel is too hard; if it is below 5, the gel structure has difficulty forming because protonation prevents the formation of covalent bonds.<ref>{{Cite journal |last1=Matringe |first1=E. |last2=Tan Luu |first2=R. Phan |last3=Lorient |first3=D. |date=1999-09-01 |title=Functional Properties of Milk-Egg Mixtures |journal=Journal of Food Science |language=en |volume=64 |issue=5 |pages=787–791 |doi=10.1111/j.1365-2621.1999.tb15912.x |issn=1750-3841}}</ref>

== Physical-chemical 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.<ref>{{Cite journal |last1=Longrée |first1=Karla |last2=Beaver |first2=Sharie |last3=Buck |first3=Paul |last4=Nowrey |first4=Joseph E. |year=1966 |title=Viscous Behavior of Custard Systems |journal=Journal of Agricultural and Food Chemistry |volume=14 |issue=6 |pages=653–659 |doi=10.1021/jf60148a033}}</ref> On the other hand, 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".<ref>{{YouTube|BN2D5y-AxIY|BRAINIAC Science Abuse – John Tickle Walks On Custard (25 June 2008)}}</ref>

== See also == {{Cookbook}} {{Portal|Food}} * List of desserts * List of custard desserts * Custard cream * Bird's Custard – brand of imitation custard * Eggnog – sweetened dairy-based beverage * Pudding – dessert or savory dish

== References == {{reflist|30em}}

== External links == * {{wiktionary inline}}

{{Dessert sauces}} {{English cuisine}}

* Category:British desserts Category:Dairy products Category:English cuisine Category:Food ingredients Category:Steamed foods Category:American desserts Category:Types of food Category:Creamy dishes