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- What do I need to know about cleanliness in food preparation?
- What exactly is cross-contamination and what should I do about it?
- My friend passes the egg yolk back and forth from shell half to shell half when separating eggs. Is this the best way to separate eggs?
- Doesn’t cooking destroy bacteria? Is there any general rule for cooking eggs?
- How long should I cook eggs?
- Are there any food-safety recommendations for microwaving eggs?
- Is it true that acid can kill bacteria?
- What should I do about some of my favorite egg recipes that call for raw or lightly cooked eggs?
- Other than cooking them, are there alternatives for raw egg whites?
- How can pasteurized shell eggs be used?
- You can’t cook ice cream, can you?
- Once I’ve cooked an egg dish, can I leave it out for buffet serving?
- Why is refrigeration important?
- What should I consider when buying eggs?
- What is the best way to store raw eggs?
- How should I store leftover egg whites and yolks?
- Can I freeze combination dishes containing eggs?
- How should I defrost frozen eggs, egg products and cooked egg dishes?
- Can I use recipes that call for eggs at room temperature?
- What should I do with egg-containing leftovers?
What do I need to know about cleanliness in food preparation?
Cleanliness throughout the kitchen and in every step of food preparation is the first step to prevent the spread of bacteria. It’s important to wash your hands, utensils, equipment and work surfaces thoroughly in hot, soapy water for at least 20 seconds before and after you come into contact with any food. Then, rewash after you prepare each item and before you prepare another food. Also wash your hands after you use the bathroom or help a child to do so, change diapers, come into contact with body fluids or handle pets.
To guard against bacteria lurking in pores, use plastic or other non-porous cutting boards. Clean them thoroughly each time you use them by running them through your dishwasher or washing them with hot, soapy water. For further protection, sanitize them with a bleach solution – about 1 teaspoon chlorine bleach to 1 quart water. Use paper towels to clean kitchen surfaces or wash cloth towels often in your washer’s hot cycle.
Only clean, uncracked eggs pass the grading process, but breakage can occur once the eggs have been packed and shipped. Use only clean eggs with unbroken shells and discard any eggs that are unclean, cracked, broken or leaking. Eggshells are washed and sanitized before packing and incorrect home procedures might infect the contents, so avoid washing eggshells before you use eggs.
What exactly is cross-contamination and what should I do about it?
Cross-contamination is the spread of bacteria from people to food or from one food or piece of equipment to another. To help prevent it, in addition to cleanliness, it’s important to separate foods – particularly to separate raw meat, fish, seafood and poultry from other foods, especially ready-to-eat foods.
At the supermarket, select perishable foods last. Separate raw meat, fish, seafood and poultry from eggs and other foods in your grocery cart. At home, refrigerate raw shell eggs in their cartons in the coldest part of the refrigerator, away from any meats that might drip juices or any produce that might come into contact with eggshells. Cover or wrap well any egg mixtures or leftover cooked egg dishes before refrigerating.
With hot, soapy water, thoroughly wash any bowl, pan, blender or other container which has held a raw egg mixture before you use it again for more eggs or another food. Do the same with any container that has held raw meat, fish, seafood or poultry. Also use separate cutting boards for raw meat, fish, seafood, poultry and other foods, particularly cooked and ready-to-eat foods. Thoroughly wash and sanitize work surfaces, cutting boards and utensils, such as beaters, after each use.
My friend passes the egg yolk back and forth from shell half to shell half when separating eggs. Is this the best way to separate eggs?
No, it’s not. Bacteria are so very tiny that, even after washing and sanitizing, it’s possible that some bacteria may remain in the shell’s pores. The shell might also become contaminated from other sources. When you break or separate eggs, it’s best to avoid mixing the yolks and whites with the shells. Rather than broken shell halves or your hands, use an inexpensive egg separator or a funnel when you separate eggs to help prevent introducing bacteria. Also use a clean utensil to remove any bits of eggshell that fall into an egg mixture and avoid using eggshells to measure other foods.
Doesn’t cooking destroy bacteria? Is there any general rule for cooking eggs?
Even light cooking will begin to destroy any Salmonella that might be present, but proper cooking brings eggs and other foods to a temperature high enough to destroy them all. For eggs, the white will coagulate (set) between 144 and 149° F, the yolk between 149 and 158° F, and whole egg between 144 and 158° F. Egg products made of plain whole eggs are pasteurized (heated to destroy bacteria), but not cooked, by bringing them to 140° F and keeping them at that temperature for 3 1/2 minutes. If you bring a food to an internal temperature of 160° F, you will instantly kill almost any bacteria. By diluting eggs with a liquid or sugar (as in custard), you can bring an egg mixture to 160° F. Use these temperatures as rough guidelines when you prepare eggs.
Doesn’t cooking destroy bacteria? Is there any general rule for cooking eggs?
Even light cooking will begin to destroy any Salmonella that might be present, but proper cooking brings eggs and other foods to a temperature high enough to destroy them all. For eggs, the white will coagulate (set) between 144 and 149° F, the yolk between 149 and 158° F, and whole egg between 144 and 158° F. Egg products made of plain whole eggs are pasteurized (heated to destroy bacteria), but not cooked, by bringing them to 140° F and keeping them at that temperature for 3 1/2 minutes. If you bring a food to an internal temperature of 160° F, you will instantly kill almost any bacteria. By diluting eggs with a liquid or sugar (as in custard), you can bring an egg mixture to 160° F. Use these temperatures as general rules when cooking eggs
How long should I cook eggs?
Cook egg dishes according to the following guidelines and then serve them promptly.
Scrambled Eggs, Omelets and Frittatas
Cook until the eggs are thickened and no visible liquid egg remains.
To cook both sides and increase the temperature the eggs reach, cook slowly and either baste the eggs, cover the pan with a lid or turn the eggs. Cook until the whites are completely set and the yolks begin to thicken but are not hard
For classic poached eggs cooked gently in simmering water, cook until the whites are completely set and the yolks begin to thicken but are not hard, about 5 minutes. For steamed eggs cooked in ‘poaching’ inserts set above simmering water, cook until the whites are completely set and the yolks begin to thicken but are not hard, about 6 to 9 minutes. Avoid precooking and reheating poached eggs.
Baked Goods, Hard Boiled Eggs
These will easily reach internal temperatures of more than 160° F when they are done. Note, though, that while Salmonella are destroyed when hard-boiled eggs are properly prepared, hard-boiled eggs can spoil more quickly than raw eggs. After cooking, cool hard-boiled eggs quickly under running cold water or in ice water. Avoid allowing eggs to stand in stagnant water. Refrigerate hard-boiled eggs in their shells promptly after cooling and use them with 1 week.
French toast, Monte Cristo sandwiches, crab or other fish cakes, quiches, stratas, baked custards, most casseroles
Cook or bake until a thermometer inserted at the center shows 160° F or a knife inserted near the center comes out clean. You may find it difficult to tell if a knife shows uncooked egg or melted cheese in some casseroles and other combination dishes that are thick or heavy and contain cheese – lasagna, for example. To be sure these dishes are done, check to see that a thermometer at the center of the dish shows 160° F. Also use a thermometer to help guard against uneven cooking due to hot spots and inadequate cooking due to varying oven temperatures.
Soft (stirred) custards, including cream pie, eggnog and ice cream bases
Cook until thick enough to coat a metal spoon with a thin film and a thermometer shows 160° F or higher. After cooking, cool quickly by setting the pan in ice or cold water and stirring for a few minutes. Cover and refrigerate to chill thoroughly, at least 1 hour.
Soft (pie) meringue
Bake a 3-egg-white meringue spread on a hot, fully cooked pie filling in a preheated 350° F oven until the meringue reaches 160° F, about 15 minutes. For meringues using more whites, bake at 325° F (or a lower temperature) until a thermometer registers 160° F, about 25 to 30 minutes (or more). The more egg whites, the lower the temperature and longer the time you need to cook the meringue through without excessive browning. Refrigerate meringue-topped pies until serving. Return leftovers to the refrigerator.
Are there any food-safety recommendations for microwaving eggs?
All models of microwave ovens tend to cook foods unevenly, leaving cold spots. To encourage more even cooking, cover the dish, stir the ingredients, if possible, and either use a turntable or rotate the dish at least once or twice during the cooking time.
Though it’s unrelated to potential bacteria, another safety factor in microwaving eggs is that you must break the eggs out of their shells. If you put an egg in its shell in the microwave, it’s likely to explode. Microwaves heat so quickly that steam builds up faster than an egg can ‘exhale’ it through its pores and the steam bursts through the shell. For the same reason, when microwaving, always prick the yolk of an unbeaten egg with the tip of a knife or a wooden pick. The vent you create allows the steam to escape safely.
Is it true that acid can kill bacteria?
Yes, but counting on acid for total kill of all bacteria is an iffy proposition. Salmonella will not grow in a recipe that has a pH (acid level) of 4.0 or lower. Some pickled egg recipes consistently reach this level of acidity, but few other recipes do. It’s also difficult to reach and maintain a specific pH because many acidic ingredients don’t have a constant pH. Eggs themselves increase in pH as they age. Some recipes may test as sufficiently acidic one day and not the next. And, without a pH meter, it’s hard to accurately measure the pH of a finished dish. For these reasons, it’s best not to rely on acid ingredients to destroy bacteria.
What should I do about some of my favorite egg recipes that call for raw or lightly cooked eggs?
Although the overall risk of egg contamination is very small, the risk of foodborne illness from eggs is highest in raw and lightly cooked dishes. To eliminate risk and ensure food safety, replace all your recipes calling for raw or lightly cooked eggs with cooked egg recipes or use pasteurized shell eggs or egg products when you prepare them. To cook eggs for these recipes, use the following methods to adapt your recipes:
Cooking Whole Eggs for Use in Recipes
As a nutritious combination of egg whites and yolks, whole eggs should be fully cooked for assured safety in recipes that call for raw or lightly cooked eggs. The following method can be used with any number of eggs and works for a variety of recipes.
In a heavy saucepan, stir together the eggs and either sugar, water or other liquid from the recipe (at least 1/4 cup sugar, liquid or a combination per egg). Cook over low heat, stirring constantly, until the egg mixture coats a metal spoon with a thin film or reaches 160° F. Immediately place the saucepan in ice water and stir until the egg mixture is cool. Proceed with the recipe.
Cooking Egg Yolks for Use in Recipes
Because egg yolks are a fine growth medium for bacteria, cook them for use in mayonnaise, Hollandaise sauce, Caesar salad dressing, chilled soufflés, chiffons, mousses and other recipes calling for raw egg yolks. The following method can be used with any number of yolks.
In a heavy saucepan, stir together the egg yolks and liquid from the recipe (at least 2 tablespoons liquid per yolk). 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.
Cooking Egg Whites for Use in Recipes
Cooking egg whites before use in all recipes is recommended for full safety. The following method can be used with any number of whites and works for chilled desserts as well as Seven-Minute Frosting, Royal Icing and other frosting recipes calling for raw egg whites.
In a heavy saucepan, the top of a double boiler or a metal bowl placed over water in a saucepan, stir together the egg whites and sugar from the recipe (at least 2 tablespoons sugar per white), water (1 teaspoon per white) and cream of tartar (1/8 teaspoon per each 2 whites). Cook over low heat or simmering water, beating constantly with a portable mixer at low speed, until the whites reach 160° F. Pour into a large bowl. Beat on high speed until the whites stand in soft peaks. Proceed with the recipe.
Note that you must use sugar to keep the whites from coagulating too rapidly. Test with a thermometer as there is no visual clue to doneness. If you use an unlined aluminum saucepan, eliminate the cream of tartar or the two will react and create an unattractive gray meringue.
The egg whites in an Italian meringue (made by adding hot sugar syrup to egg whites while beating them) do not reach much above 125° F, so this method is not recommended, except for dishes that are further cooked. If, however, you bring the sugar syrup all the way to the hardball stage (250 to 266° F), the whites will reach a high enough temperature. You can use sugar syrup at hardball stage for Divinity and similar recipes.
Other than cooking them, are there alternatives for raw egg whites?
Yes. You can use pasteurized dried or pasteurized refrigerated liquid egg whites. Egg substitutes often contain gums and/or added salt which can hamper foaming. Pasteurized dried and pasteurized liquid egg whites on the retail market either contain no other ingredients – for recipes where little foaming is required – or contain only a whipping agent – for recipes that require a stable foam. Follow package directions to substitute pasteurized dried or pasteurized refrigerated liquid egg whites for raw egg whites or use about 2 tablespoons water and 2 teaspoons dried egg white or 2 to 3 tablespoons liquid egg white for each large egg white.
How can pasteurized shell eggs be used?
Pasteurized shell eggs are heat-treated to destroy any bacteria, should they be present, and are especially suitable for preparing egg recipes that are not fully cooked, but may also be used for other recipes, including baked goods. The heating process may create cloudiness in the whites and increase the beating time needed for foam formation. When you separate pasteurized shell eggs for beating, allow up to about four times as much time for full foam formation to occur in egg whites as you would for the whites of regular eggs. Prepare other recipes as usual.
You can keep pasteurized shell eggs refrigerated for at least 30 days from the pack date (a three-digit number on the short side of the carton which represents the day of the year, with 001 = January 1 and 365 = December 31), but do not freeze them.
If pasteurized shell eggs are not available in your area, use the cooking methods outlined on pages 11 and 12 or, in place of raw egg whites, use pasteurized dried or pasteurized liquid egg whites.
You can’t cook ice cream, can you?
Actually, you should always make an egg-based ice cream from a cooked stirred custard. After cooking and cooling, transfer the custard to a small container, then quickly and thoroughly chill it before freezing. Custard that cools too slowly provides an ideal temperature for bacterial growth. If you are making several batches and your refrigeration facilities are not adequate for quick cooling, substitute pasteurized shell eggs or pasteurized refrigerated liquid or pasteurized frozen eggs for the eggs in your recipe.
Once I’ve cooked an egg dish, can I leave it out for buffet serving?
Proper cooking destroys any bacteria that may have been present before cooking, but a dish may be cross-contaminated after cooking by people, other foods or cooking utensils or equipment. If a dish is contaminated, bacteria will multiply rapidly at temperatures between 40 and 140° F. So, promptly serve eggs and egg-containing dishes after cooking. For buffet service, use ice or freezer packs with commercial coolant to keep cold foods cold (40° F or lower) and food warmers or thermal containers to keep hot foods hot (140° F or higher). Serve buffet foods in small dishes and replenish them with fresh dishes often, rather than leaving foods at room temperature.
Why is refrigeration important?
Rapid growth of bacteria can occur between 40 and 140° F. Using cold temperatures keeps bacteria from growing to large enough numbers to cause illness. Salmonella will not grow when held below 40° F. Freezing does not destroy Salmonella, but may impair some cells. In general, while the quality of the frozen food may be altered by the freezing process, frozen foods will emerge from the freezer just as safe or unsafe as they entered it.
What should I consider when buying eggs?
Buy uncracked Grade AA or A eggs from refrigerated cases only. Then, get them home quickly and refrigerate them immediately. If it’s hot outside or the distance is great, pack eggs and other perishable foods with ice or commercial coolant in an insulted bag or cooler in your car, rather than the trunk. Keep eggs refrigerated until you’re ready to use them.
What is the best way to store raw eggs?
Continually keep raw shell eggs, broken-out eggs, egg mixtures, prepared egg dishes and other perishable foods refrigerated at 40° F or below when you’re not cooking or eating them. These foods should not be left at room temperature for more than 2 hours, including the time you use to prepare and serve them. Allow no more than 30 minutes to 1 hour when it’s 85° F or hotter.
To guard against breakage and odor absorption and to help prevent the loss of carbon dioxide and moisture which lowers egg quality, store raw shell eggs in their cartons. Place egg cartons on a middle or lower shelf where the temperature will fluctuate less than on the door.
Refrigerated raw shell eggs will keep without significant quality loss for about 4 to 5 weeks beyond the pack date or about 3 weeks after you bring them home. For longer storage, beat whole eggs just until blended, pour into freezer containers, seal the containers tightly, label with the number of eggs and the date and freeze for up to 1 year. Substitute 3 tablespoons thawed whole egg for 1 Large fresh egg. Avoid freezing hard-boiled whole eggs or hard-boiled whites as freezing causes them to become tough and watery.
Check occasionally with a thermometer to be sure your refrigerator temperature is 40° F or below and that your freezer temperature is 0° F or below. To maintain safe temperatures, allow cool air to circulate, rather than packing your refrigerator.
How should I store leftover egg whites and yolks?
You can refrigerate raw whites for up to 4 days and unbroken raw yolks, covered with water, for up to 2 days in a tightly sealed container. If you can’t use the yolks quickly enough, hard boil them just as you would cook whole eggs in the shell, drain them well and refrigerate them in a tightly sealed container for up to 4 or 5 days. For longer storage, freeze raw whites, sugared or salted yolks and cooked yolks for up to 1 year.
To freeze egg whites, break and separate the eggs, one at a time, making sure that no yolk gets in the whites. Pour the whites into freezer containers, seal the containers tightly, label with the number of egg whites and the date and freeze. For faster thawing and easier measuring, first freeze each white in an ice cube tray and then transfer to a freezer bag or container. Substitute 2 tablespoons thawed egg white for 1 Large fresh white.
Raw egg yolks require special treatment because the yolk’s gelation property causes it to thicken or gel when frozen. If frozen as is, the yolk with eventually become so gelatinous it will be almost impossible to use. To help retard gelation, beat in either 1/8 teaspoon salt or 1 1/2 teaspoons sugar or corn syrup for each 1/4 cup egg yolks (4 Large yolks). Label the container with the number of yolks, the date and whether you’ve added salt (for main dishes) or sweetener (for baking or desserts) and freeze. Substitute 1 tablespoon thawed egg yolk for 1 Large fresh yolk.
Can I freeze combination dishes containing eggs?
Depending on the ingredients used, wrapping and other factors, combination dishes containing eggs may or may not freeze well. You can determine the likelihood of successful freezing for a combination dish by consulting the cold storage guide available through the USDA Meat and Poultry hotline at 1 (888) 674-6854. Most egg-containing combination dishes should be frozen for no more than 1 to 3 months. Whether you thaw a frozen egg dish first or heat it while still frozen, cook or bake it until a thermometer at the center registers 160° F or more.
How should I defrost frozen eggs, egg products and cooked egg dishes?
Defrost frozen eggs, egg products and cooked egg dishes in the refrigerator overnight or under running cold water, not at room temperature. Cook them thoroughly and serve them promptly after they’re thawed.
Can I use recipes that call for eggs at room temperature?
Yes. Some cake recipes call for eggs to be at room temperature before they are combined with creamed fat and sugar. Cold eggs could harden the fat and curdle the batter which might affect the finished cake’s texture. For these recipes, remove eggs from the refrigerator about 20 to 30 minutes before you use them or put them in a bowl of warm water while you assemble other ingredients.
And, although eggs are easiest to separate when cold, whites reach their fullest volume if allowed to stand at room temperature for about 20 to 30 minutes before beating. For both creamed cakes and separately beaten whites, it’s only necessary to take the chill off the eggs. They don’t actually have to reach room temperature. For all other recipes, use eggs straight from the refrigerator.
What should I do with egg-containing leftovers?
Promptly after you serve them, divide large amounts of leftovers into small, shallow containers and refrigerate them immediately so they’ll cool quickly. Then, thoroughly reheat them and eat them within 2 to 3 days. Without tasting them, discard any egg-containing leftovers that have been refrigerated more than 3 days.