Eggnog and holidays seem to go hand in hand. While prepared eggnog is readily available at the supermarket, there is nothing like homemade eggnog. But homemade eggnog has the potential to spoil holiday fun and cause Salmonella poisoning from the use of raw or undercooked eggs. Salmonella bacteria is a potential risk even when refrigerated eggs with clean, uncracked shells are used.
Since eggs are a standard ingredient in most homemade eggnog recipes, let’s look at someways to convert a special family recipe into a safe recipe.
Use a cooked egg base. FoodSafety.gov recommends a cooked egg base for eggnog. This is especially important if you are serving people at high risk for foodborne infections: young children and pregnant women (non-alcoholic eggnog), older adults, and those with weakened immune systems. Eggs must be cooked to 160 °F to kill bacteria that may be present such as Salmonella. A cooked egg base or custard is made by heating half of the the milk and/or cream to almost boiling and ever so slowly adding the beaten egg yolks (or sometimes the whole egg) and sugar (or any sugar substitute). Continue to cook and stir the mixture gently until an internal temperature of 160 °F is reached. At this temperature, the mixture will firmly coat a metal spoon and remain separated when a finger is drawn through it. Do not let the mixture go beyond 160 °F as above that temperature, the eggs are likely to curdle. (If curdling occurs, put the mixture in a blend and blend until smooth.) Place the mixture in a bowl of ice water to stop the cooking action and prevent curdling or further curdling and then refrigerate.
Use pasteurized eggs yolks. Eggnog may be safely made at home by using whole, liquid or pasteurized eggs or egg substitutes in place of raw eggs. Pasteurized eggs are found next to regular eggs at the store. Commercial pasteurization of eggs is a heat process at low temperatures that destroys any Salmonella that might be present without having a noticeable effect on flavor or nutritional content. Even if you are using pasteurized eggs for your eggnog, both the FDA and the USDA recommend starting with a cooked egg base for optimal safety. When egg substitute products are used, some experimentation might be needed to figure out the right amount to add for the best flavor.
Use alcohol to inhibit bacterial growth. While alcohol will inhibit bacterial growth, adding alcohol (in amounts recommended by most recipes) will not be sufficient to kill bacteria. However, if one wants to use alcohol, Cooks Illustrated suggests that 1 1/2 ounces of 80 proof liquor per egg and three weeks of aging in the refrigerator is sufficient to kill bacteria when dairy is omitted until ready to serve. Such was conclusively proven by microbiologists at Rockefeller University where salmonella bacteria was purposely added to eggnog and analyzed over a three-week period. By the three-week mark, the alcohol had rendered the eggnog completely sterile.
Substitute egg whites. If a recipe calls for adding beaten egg whites to the hot egg/milk custard, use pasteurized egg whites. While pasteurized egg whites do not whip to the same volume as raw egg, they are safe. It has not been proven that raw egg whites are free of Salmonella bacteria; NOR has it been shown that when adding them to the hot milk/egg custard, the custard remains hot enough to kill any bacteria. Another good substitute is whipping cream whipped to soft peaks added at the time of serving.
Here’s to a safe and worry-free holiday! Follow these suggestions for your favorite eggnog recipe to assure everyone can enjoy delicious, creamy homemade eggnog without worry of a foodborne illness.