While commercially made eggnog is stocked in stores as early as mid-October, some families still prefer to celebrate the season with a homemade version.

It’s a festive recipe, but one that calls for a measure of caution. Eggnog prepared from scratch with raw eggs can present a risk for salmonellosis, food poisoning caused by the Salmonella bacterium. Young children, expectant mothers, older adults and people with weakened immune systems are especially vulnerable.

The U.S. Food and Drug Administration recommends making homemade eggnog with a cooked custard base. Rum, whiskey or other alcohol cannot be counted on to kill all of the bacteria in eggnog made with contaminated eggs, and the FDA recommends preparing the custard base even when using pasteurized eggs.

The U.S. Department of Agriculture recommends refrigerating commercial eggnog for no more than five days or freezing it for no more than six months. Homemade eggnog can be refrigerated for 4 days and should not be frozen.

The Virginia Egg Council notes on its website that eggnog is probably descended from posset, a drink of British origins that was made with eggs, milk and ale or wine, and served hot. When colonists brought the recipe to the New World, they began to prepare it with rum or bourbon.

Eggs were considered a comfort food with medicinal qualities, which might explain why a nutrient-rich egg beverage was prepared during the colder part of the year. It also may have been a special treat for the winter holidays, when more people traveled to see friends and family.

Thirsty yet? Here’s a classic recipe from the American Egg Board.

Saint Nick’s Eggnog

6 large eggs
1/4 cup sugar
1/4 teaspoon salt
4 cups whole milk, divided
1 teaspoon vanilla
12 cinnamon sticks for garnish

In a large, heavy saucepan, beat eggs, sugar and salt until blended. Stir in 2 cups milk.

Stirring constantly but gently over low heat, cook until mixture is just thick enough to just coat a metal spoon with a thin film and temperature reaches 160°, about 15 minutes. Do not allow to boil. Remove from heat immediately.

Stir in remaining 2 cups milk and vanilla. Refrigerate, covered, until thoroughly chilled, several hours or overnight. Makes 12 ½-cup servings.

Just before serving, stir brandy, liqueur, rum or bourbon into eggnog, if desired. For a festive presentation, garnish with cinnamon sticks and/or whipped cream, ground nutmeg or candy canes.

The egg board makes the following recommendations:

• Low heat, a heavy sauce pan, constant stirring and patience are the keys to making the eggnog. If you increase the cooking temperature to try to speed the process along, the mixture is likely to curdle. Stirring constantly, making sure to cover the entire bottom and corners of the pan, prevents scorching and ensures that the mixture heats.
  
  
• Watch carefully and test frequently toward the end of the cooking time, after about 10 to 12 minutes. Undercooked eggnog will be thin and watery; overcooked custard will curdle. The difference is a matter of only a few degrees.
  
  
• For perfectly smooth eggnog, pour through a strainer before chilling.
  
  
• For a richer eggnog, substitute half-and-half or light cream for some of the milk.
  
  
• To keep eggnog cold during a party, set a punch bowl or pitcher in a bed of crushed ice, or freeze some of the eggnog in ice cube trays or an ice ring mold and add to the bowl right before the party.
  
  
• Use leftover eggnog in French toast or pancake batter.