FOOD RESOURCE COLLEGE OF HEALTH AND HUMAN SCIENCES, OREGON STATE UNIVERSITY
CUSTARD
Excerpts from Bender, Arnold E. 1990. Dictionary of Nutrition and Food Technology. Butterworths, Boston.
May refer to custard powder, or to egg custard. Egg custard is composed of milk and egg cooked together.
is a cooked or baked mixture consisting mainly of eggs, milk, and
sugar
is a colloidal sol or gel made up of egg, milk, and/or sugar and flavorings.
Garrett, Theodore Francis (edited by). 1898. the Encyclopedia of Practical Cookery. L. Upcott Gill, 170, Strand, W.C. London. Vol. I
are essentially English preparations made chiefly of eggs, sugar, and milk mixed together in various proportions. They may be either baked or boiled and with or without a crust.
Grimes, William. 2004. Eating Your Worlds. Oxford University Press.
is a dessert or sauce made by heating milk, eggs, and usually sugar, and cooking below the boiling point.
- ORIGIN Middle English crustarde, custarde (an open pie containing meat or fruit), from Old French crouste.
Webber Comment:
A custard is made of egg, milk, sugar and usually salt and
flavoring. Through application of heat and manipulation, custards
can become a viscous sauce or a semi-rigid gel. In each case
denaturation of the egg protein, ovalbumin, conalbumin and
ovoglobulin, is primarily responsible for the thickening of the
custard. Stirred custards are cooked on top of the range while gel
type custards are usually baked.
Custards may be altered by manipulation or ingredient
variation. Because egg is the primary structural ingredient of a
custard, some differences are seen when fresh, frozen, old, dried
or egg substitutes are used. Eggs other than form a chicken, for
Example duck or turkey, also influence custard quality. Milk,
although not as structurally important as egg, does contribute to
the viscosity or gel strength of the finished product. Calcium
ions present in the milk are needed in the formation of a thicker
custard, as custards made with water will not gel or thicken.
Different processed milks will also influence the custard quality.
Nonhomogenized milk produces a baked custard with a thinner crust,
more delicate browning and better sheen than those custards made
with homogenized milk. The stirred custard usually is considered
to have "more body". Sugar is also important to the viscosity and
gel strength of custards in that sugar tends to increase the
denaturation temperature of the egg proteins resulting in a less
stiff product. Salt and flavoring have no appreciable affect on
custard quality other than for taste.
Proportion of ingredients is important to custard quality. The concentration of egg protein is proportional to the viscosity
or gel strength of the custard. With increasing concentration, the
more viscous a custard sauce or the firmer the gel strength of a
baked custard. Also with increased egg protein the product becomes
more sensitive to end point temperature. End point temperature is
the point at which optimum denaturation has occurred without
curdling or syneresis. Milk serves to dilute the egg protein so
less viscosity and gel strength are observed with increasing
proportions of milk. Because sugar increases the denaturation
temperature of egg proteins, increased sugar concentrations results
in softer custards. At a 30% sucrose concentration, a custard will
not gel at all.
Producing a good quality custard depends on a number of
factors. In addition to the proportion and ingredient variation,
temperature and rate of cooking are important. A custard heated
slowly begins to thicken at a lower temperature, thickens gradually
over a wider temperature range and reaches doneness at a lower
temperature. On the other hand, a custard heated rapidly must be
heated to a higher temperature before thickening begins and
overcooking, resulting in curd formation or porosity, occurs
easily. Syneresis or weeping can result as the curds separate from
the serum. Slow cooking can be achieved by placing the baked
custard mixture in a waterbath in the oven or using the double
boiler with a stirred custard. Endpoint is indicated when the
stirred custard "coats the spoon", or when a knife inserted into
the baked custard "comes out clean".
