Food Safety Of Jerky

     When raw meat or poultry is dehydrated at home -- either in a warm oven or a food dehydrator -- to make jerky which will be stored on the shelf, pathogenic bacteria are likely to survive the dry heat of a warm oven and especially the 130 to 140^o F of a food dehydrator. Included here is the scientific background behind drying food to make it safe and the safest procedure  to follow when making homemade jerky.

What is Jerky?  

     Jerky is a nutrient-dense meat that has been made lightweight by drying. A pound of meat or poultry weighs about four ounces after being made into jerky. Because most of the moisture is removed, it is shelf stable -- can be stored without refrigeration -- making it a handy food for backpackers and others who don't have access to refrigerators.

     Jerky is a food known at least since ancient Egypt. Humans made jerky from animal meat that was too big to eat all at once, such as bear, buffalo, or whales. North American Indians mixed ground dried meat with dried fruit or suet to make "pemmican." "Biltong" is dried meat or game used in many African countries. Our word "jerky" came from the Spanish word "charque."

How Can Drying Make it Safe?  

     Drying is the world's oldest and most common method of food preservation. Canning technology is less than 200 years old and freezing became practical only during this century when electricity became more and more available to people. Drying technology is both simple and readily available to most of the world's culture.

     The scientific principal of preserving food by drying is that by removing moisture, enzymes cannot efficiently contact or react with the food. Whether these enzymes are bacterial, fungal, or naturally occurring autolytic enzymes from the raw food, preventing this enzymatic action preserves the food from biological action.

Why is Temperature Important When Making Jerky?  

     Illnesses due to Salmonella and E. coli O157:H7 from homemade jerky raise questions about the safety of traditional drying methods for making beef and venison jerky. The USDA Meat and Poultry Hotline's current recommendation for making jerky safely is to heat meat to 160^o F before the dehydrating process. This step assures that any bacteria present will be destroyed by wet heat. But most dehydrator instructions do not include this step, and a dehydrator may not reach temperatures high enough to heat meat to 160^o F.

     After heating to 160^o F, maintaining a constant dehydrator temperature of 130 to 140^o F during the drying process is important because:

• the process must be fast enough to dry food before it spoils; and

• it must remove enough water that microorganisms are unable to grow.

Why is it a Food Safety Concern to Dry Meat Without First Heating it to 160^o F?  

     The danger is dehydrating meat and poultry without cooking it to a safe temperature first is that the appliance will not heat the meat to 160^o F -- a temperature at which bacteria are destroyed -- before it dries. After drying, bacteria become much more heat resistant.

What are the USDA Meat and Poultry Hotline's Recommendations for Making Homemade Jerky?  

     Additionally, safe handling and preparation methods must always be used, including:

• Always wash hands thoroughly with soap and water before and after working with meat products.

• Use clean equipment and utensils.

• Keep meat and poultry refrigerated at 40^o F or slightly below; use or freeze ground beef and poultry within 2 days; whole red meats, within 3 to 5 days.

• Defrost frozen meat in the refrigerator, not on the kitchen counter.

• Marinate meat in the refrigerator. Don't save marinade to re-use. Marinades are used to tenderize and flavor the jerky before dehydrating it.

• Steam or roast meat and poultry to 160^o F as measured with a meat thermometer before dehydrating it.

• Dry meats in a food dehydrator that has an adjustable temperature dial and will maintain a temperature of at least 130 to 140^o F throughout the drying process.

For additional food safety information about meat, poultry, or eggs, call the toll-free USDA Meat and Poultry Hotline at
1 (800) 535-4555; Washington, DC, call (202) 720-3333; TTY: 1 (800) 256-7072. It is staffed by home economists, dietitians, and food technologists weekdays from 10 a.m. to 4 p.m. Eastern time, year round. An extensive selection of food safety recordings can be heard 24 hours a day using a touch-tone phone.

Food Safety and Inspection Service, United States Department of Agriculture, Washington DC 20250-3700