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Enjoying Safe Homemade Ice Cream

Edited by: Mary Schroeder, M.S., R.D. & Pat Kendall, Ph.D., R.D., Colorado State - Summer 2005

Homemade ice cream is a special summertime treat. However, for hundreds of consumers each year it can also become a threat as they suffer the effects of salmonellosis. According to a report by the U.S. Centers for Disease Control and Prevention (CDC), between 1996 and 2000, 17 outbreaks in the U.S. involving more than 500 people were traced to Salmonella bacteria in homemade ice cream. Even commercially-prepared ice cream can become plagued with Salmonella, as evidenced by the recent nationwide recall of "Cake Batter" ice cream from Cold Stone Creamery stores in the U.S.

The Cold Stone Creamery outbreak was discovered when multiple cases of Salmonella Typhimurium infection were reported in Minnesota, Washington, Oregon and Ohio with the common pattern of consuming "Cake Batter" ice cream shortly before onset of illness. In homemade ice cream, Salmonella Enteritidis, which can be transmitted from the hen to the egg yolk before the shell forms, is the more common culprit. Because of this, it's no longer safe to assume that a clean, uncracked raw egg is safe to eat.

Salmonella infection is characterized by fever, diarrhea and abdominal cramps usually beginning 12 to 72 hours after eating or drinking a contaminated food item and lasting up to a week. Although most people require no medical treatment, it can be life threatening for those at high risk for foodborne illness, including infants, older people, pregnant women and people with weakened immune systems.

While commercially manufactured ice cream is typically made with pasteurized eggs or egg products, recipes for homemade ice cream often use raw eggs in the base mixture. Here are some suggestions for safe alternatives to using raw eggs in your homemade ice cream:

• Find a recipe that is eggless. It's easy and tastes just as good!
• Use pasteurized shell eggs or pasteurized egg substitutes in recipes calling for raw eggs. They can be found in the dairy case near the regular eggs. The FDA requires that pasteurized shell eggs be individually marked or specially packaged to prevent intermingling with unpasteurized eggs. Although pasteurized eggs may cost a few cents more, the pasteurization process destroys the Salmonella bacteria.
• Use a recipe that contains a cooked custard base. The custard base must reach 160º F measured with a food thermometer, in order to kill the Salmonella Enteritidis. This is also the point that at which the mixture will coat a metal spoon. Resist the temptation to taste-test the mixture during preparation when the custard isn't fully cooked. After cooking, chill the custard thoroughly before freezing.

Even when using pasteurized products, the FDA and the USDA advise consumers to start with a cooked base for optimal safety, especially if serving people at high risk for foodborne illness. Additionally, use only pasteurized milk and cream when making homemade ice cream. A recipe for homemade ice cream using a cooked egg base is available on the American Egg Board's website, http://www.aeb.org, along with recipes for other foods traditionally made with raw or undercooked eggs, such as mayonnaise, Caesar salad dressing, and eggnog. The University of Nebraska Extension also offers an eggless ice cream recipe at http://lancaster.unl.edu/food/icecream.htm

Sources:

1. Enjoying Homemade Ice Cream without the Risk of Salmonella Infection. Center for Food Safety and Applied Nutrition. August 2004. www.cfsan.fda.gov/~dms/fs-eggs5.html
2. Bren, L. Homemade Ice Cream: A Safe Summertime Treat? FDA Consumer Magazine, July-August, 2004.
3. Safety comes first with homemade ice cream. Deb Adamson. Colorado State University Extension, Weld County. Aug., 2002.

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