Health Department - Environmental
Safety and Inspection Service
Safety of Jerky
United States Department of Agriculture
Washington, D.C. 20250-3700
Slightly Revised May 2000
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 °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
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.
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."
can drying meat make it safe?
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
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.
are the types of food drying?
several types of food drying. Two types of natural
drying - sun drying and "adibatic" (shade) drying - occur
in open air. Adibatic drying occurs without heat . Solar
drying sometimes takes place in a special container that
catches and captures the sun's heat. These types
of drying are used mainly for fruits such as apricots, tomatoes,
and grapes (to make raisins).
from an artificial heat source is done by placing food in
either a warm oven or a food dehydrator. The main
components of an electric food dehydrator include:
- a source
flow to circulate the dry air;
to hold the food during the drying process; and
or leather sheets to dry certain types of foods.
is temperature important when making Jerky?
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 °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 °F.
to 160 °F, maintaining a constant dehydrator temperature
of 130 to 140 °F during the drying process is important
process must be fast enough to dry food before it spoils;
- it must
remove enough water that microorganisms are unable to grow.
is it a food safety concern to dry meat without first heating
it to 160 °F?
in dehydrating meat and poultry without cooking it to a safe
temperature first is that the appliance will not heat the
meat to 160 °F - a temperature at which bacteria are
destroyed - before it dries. After drying, bacteria
become much more heat resistant.
a dehydrator or low-temperature oven, evaporating moisture
absorbs most of the heat. Thus, the meat itself
does not begin to rise in temperature until most of the moisture
has evaporated. Therefore, when the dried meat
temperature finally begins to rise, the bacteria have become
more heat resistant and are more likely to survive . If
these surviving bacteria are pathogenic, they can cause foodborne
illness to those consuming the jerky.
research findings exist on the safety of Jerky?
been several scientific studies of meat dehydrating and lab
tests on jerky samples by the following professionals: Judy
Harrison, Cooperative Extension Service, University of Georgia; Mark
Harrison, the Center for Food Safety and Quality Enhancement,
Department of Food Science and Technology, University of
Georgia; Richard A. Holley, Food Research Institute, Agriculture
Canada, in Ontario; and William Keene of the Oregon Health
Division . In studies, the meat dehydrated included
slices of beef from the round, loin, or flank; corned beef
slices; and ground beef formed in jerky presses. Keene
examined homemade venison jerky which infected 11 people
with E. coli O157:H7.
In a related
work, factors affecting the heat resistance of E. coli O157:H7
was the subject of an April 1998 piece by J. Kauer et al., Letters
of Applied Bacteriology, Vol. 26, No. 4, page 325.
jerky studies, some samples showed total bacterial destruction
and other samples showed some bacterial survival - especially
the jerky made with ground beef . Further experiments
with lab-inoculated venison showed that pathogenic E.
coli could survive drying times of up to 10 hours and
temperatures of up to 145 °F.
study by the Harrisons and Ruth Ann Rose, also with the University
of Georgia, was published in the January 1998 Journal
of Food Protection , Vol. 61, No. 1. The authors
analyzed ground beef jerky made with a commercial beef jerky
spice mixture with and without a curing mix containing salt
and sodium nitrite.
the ground beef was inoculated with E. coli O157:H7
before making it into jerky strips and dehydrating it. The
authors found that in both the heated and unheated samples,
the jerky made with the curing mix had greater destruction
of bacteria than jerky made without it. The jerky
made with the mix and heated before dehydrating had the highest
destruction rate of bacteria.
They concluded, "For
ground beef jerky prepared at home, safety concerns related
to E. coli O157:H7 are minimized if the meat is
precooked to 160 °F prior to drying."
are the USDA meat and poultry hotline's recommendations
for making homemade Jerky?
findings support what the Hotline has been recommending to
callers. Additionally, safe handling and preparation
methods must always be used, including:
wash hands thoroughly with soap and water before and
after working with meat products.
clean equipment and utensils.
meat and poultry refrigerated at 40 °F or slightly
below; use or freeze ground beef and poultry within 2
days; whole red meats, within 3 to 5 days.
frozen meat in the refrigerator, not on the kitchen counter.
meat in the refrigerator . Don't save marinade
to re-use. Marinades are used to tenderize
and flavor the jerky before dehydrating it.
or roast meat and poultry to 160 °F as measured with
a meat thermometer before dehydrating it.
meats in a food dehydrator that has an adjustable temperature
dial and will maintain a temperature of at least 130
to 140 °F throughout the drying process.
there special considerations for wild game Jerky?
are other special considerations when making homemade jerky
from venison or other wild game. According to Keene
and his co-authors, "Venison can be heavily contaminated
with fecal bacteria - the degree varying with the hunter's
skill, wound location, and other factors . While
fresh beef is usually rapidly chilled, deer carcasses are
typically held at ambient temperatures, potentially allowing
commercially made Jerky safe?
process is monitored in federally inspected plants by inspectors
of the U.S. Department of Agriculture's Food Safety and Inspection
Service. Products may be cured or uncured, dried,
and may be smoked or unsmoked, air or oven dried. The
following terms may be on processed jerky products:
Jerky" - produced from a single piece of
Jerky Chunked and Formed" - produced from
chunks of meat that are molded and formed, then cut
Jerky Ground and Formed or Chopped and Formed" -
produced from ground or chopped meat, molded and cut
into strips. Beef Jerky containing binders or extenders
must show true product name (e.g., "Beef and
Soy Protein Concentrate Jerky, Ground and Formed" ).
(or Kind) Jerky Sausage" - the product has
been chopped and may be dried at any stage of the process,
and it is stuffed into casings.
is the safe storage time for Jerky?
packaged jerky can be kept 12 months; home-dried jerky can
be stored 1 to 2 months.
additional food safety information about meat, poultry, or
egg products, call the toll-free USDA Meat and Poultry Hotline
at 1-888-MPHotline (1-888-674-6854); for the hearing-impaired
(TTY) 1-800-256-7072. The Hotline is staffed by food safety
experts weekdays from 10 a.m. to 4 p.m. Eastern time. Food
safety recordings can be heard 24 hours a day using a touch-tone
may contact the USDA Meat and Poultry Hotline at (301) 504-6258.
is also available from the FSIS Web site: http://www.fsis.usda.gov
more information contact:
FSIS Food Safety Education Staff
Meat and Poultry Hotline: