9.2 Eggs – Custard – Basic Scientific Food Preparation Lab Manual (2024)

FAQs

What temperature do egg yolks need to reach in a custard filling to ensure any food poisoning bacteria are killed? ›

Cooking Egg Yolks for Use in Recipes

Cook over very low heat, stirring constantly, until the yolk mixture coats a metal spoon with a thin film, bubbles at the edges or reaches 160° F. Immediately place the saucepan in ice water and stir until the yolk mixture is cool. Proceed with the recipe.

So what is going on? (Or, in my custard, failing to go on?) As the liquid heats up, the yolk proteins, previously tightly packed in small granules, start to unfurl. Left to themselves, they'll make a few bonds with each other and create a tough, grainy substance at around 150 F (65C) – essentially, a hardboiled yolk.

These temperatures are raised when eggs are mixed into other liquids. For example, the coagulation and thickening of an egg, milk, and sugar mixture, as in custard, will take place between 80°C and 85°C (176°F and 185°F) and will start to curdle at 88°C to 90°C (190°F and 194°F).

Here's how to avoid one of the worst kitchen mishaps: overcooking. Egg-based puddings and custards can curdle if cooked beyond 185 degrees. We take crème anglaise off the heat when the mixture registers 175 to 180, but when making the base for ice cream we push the temperature to 180 to 185 for maximum thickness.

Egg custards contain protein, which provides good food for bacteria. If custards are not heated and cooled properly and quickly, bacteria that are present in the custard can grow quickly to dangerous number.

Custard tarts have long been a favourite pastry in Britain and the Commonwealth, where they are often called "egg custard tarts" or simply "egg custards" to distinguish the egg-based filling from the commonly served cornflour-based custards.

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.

If custard is overcooked, the protein bonds become tighter, resulting in increased thickness, curdling, and the release of water, which is observed as small tunnels in the custard.

Keep an eye on the heat when cooking the custard - too low and it won't thicken, too high and you'll have scrambled eggs.

What are the three types of egg custard? ›

There are three types of custard: baked, stirred, and frozen. Baked custards include bread pudding, flan, and cheesecake, and are prepared by baking in an oven or water bath. Boiled Custards include beverages like eggnog. Puddings, creme anglaise (krem on-GLAYZ), and pastry cream are some examples of stirred custards.

custard, mixture of eggs, milk, sugar, and flavourings which attains its consistency by the coagulation of the egg protein by heat. Baked custard contains whole eggs, which cause the dish to solidify to a gel.

Custards are of two types—stirred or baked. They are used as desserts, sauces, bases for other desserts, and some savory dishes, such as a quiche or a frittata. Pudding is a creamy dessert or filling made from eggs, milk, sugar, flavorings, and a thick- ener (such as cornstarch or gelatin).

Don't overcook the custard. It needs to be cooked to 185 F-190 F but only for 1 minute, then remove from the heat. Reaching temperatures beyond 190 F will cause watery, overcooked custard. Egg yolks have a starch digesting enzyme called alpha-amylase.

Cook egg mixtures to 160 °F.

Egg white protein coagulates between 144° F and 149° F (62.2° C and 65° C); egg yolk protein coagulates between 149° F and 158° F (65° C and 70° C); and whole egg protein coagulates between 144° F and 158° F (62.2° C and 70° C).

egg yolks and you have custard. Is the egg raw? No, all ingredients are pasteurized/cooked. Are there other reasons for frozen custards creaminess?