In October 2003, in New Mexico, there was an outbreak of Salmonella that was traced to jerky production in one of the small plants. In response to this outbreak, the Food Safety and Inspection Service initiated a series of policy changes and guidelines. Jerky is usually made from beef and the cooking guidelines for beef products should be observed. Your question is essentially, "Why is drying meat, without first heating it to 160°; F. (72° C), a food safety concern?" The danger looms when an appliance will not heat the meat to 160° F - "a temperature at which bacteria are destroyed" according to the USDA - before it dries.
After drying, bacteria become much more heat resistant. Within a dehydrator or low-temperature oven, evaporating moisture absorbs most of the heat. Consequently, the meat itself does not begin to rise in temperature until most of the moisture has evaporated. Then, when the dried meat temperature finally begins to rise, the bacteria have become more heat resistant and are more likely to survive. If these bacteria are pathogenic, they can cause food borne illness to those consuming the jerky.
What the FSIS has concluded is that it is not enough to follow the time-temperature guidelines, but to also include the humidity factor in the cooking process. It is now necessary to maintain the relative humidity of the oven at 90% or above for at least 25% of the cooking time and no less than one hour.
This ruling has started a heated and ongoing debate between the FSIS and small jerky manufacturers who claim that maintaining such high humidity in a smokehouse is difficult and may force them out of business. Another argument is that the humidity requirement changes the quality of jerky. Due to today`s microbiological concerns, particularly E.coli 0157:H7, Salmonella, and Listeria monocytogenes,
commercially made jerky must now be exposed to thermal processing. A hobbyist is not bound by those rules but we believe it is beneficial to know about the latest safety requirements for making jerky products.
The United States Department of Agriculture (USDA) has divided jerky into specific categories:
1. Jerky - The product is produced from a single piece of meat. The product can also be labeled as "Natural Style Jerky" provided that the product name is accompanied by the explanatory statement "made from solid pieces of meat."
2. Jerky Chunked and Formed - The product is produced from chunks that are molded and formed. and then cut into strips.
3. Jerky Ground and Formed or Chopped and Formed. The meat is ground, molded, pressed, and cut into strips.
It should also be noted that pork and wild game (bear, venison) meat is at risk of being infested with trichinae and should be either cooked or accordingly treated. Commercially made jerky is monitored by inspectors of the U.S. Department of Agriculture`s Food Safety and Inspection Service. Home made jerky, often made from venison, is often made in a hazardous way. Dried meat will keep for many years if kept at low humidity because bacteria will not grow under such conditions. That does not mean that all bacteria are dead.
E.coli was found in dried but uncooked jerky that has been stored at room temperature for more than a year.
Although curing salt (Cure#1) is not required in the manufacture of homemade jerky, it is recommended that it be used. Curing salt offers advantages as it...
1. Stabilizes and improves the color of meat.
2. Contributes to the characteristic flavor of cured meat.
3. Inhibits growth of spoilage and pathogenic bacteria.
4. Slows down development of rancidity of fat.
The new method of making jerky from a single piece of meat
The USDA current recommendation for making jerky safely is to heat meat to 160° F (72° C) before the dehydrating process.
This step assures that any bacteria present will be destroyed by wet heat
. Most dehydrator instructions do not include this step, and a dehydrator may not reach temperatures high enough to heat meat to 160° F. After heating to 160° F, maintaining a constant dehydrator temperature of 130°; to 140°; F (54 - 60° C) during the drying process is important because: the process must be enough to dry food before it spoils; and it must remove enough water that microorganisms are unable to grow.
The University of Wisconsin has concluded that the following temperatures are effective at killing E.coli 0157:H7 in jerky. These folks recommend that a dehydrator temperature of 145 deg. F (63 deg. C) or higher be used.
- - - - - Drying Time:
125 deg. F (52 deg. C) 10 hours
135 deg. F (57 deg. C) 8 hours
145 deg. F (63 deg. C) 7 hours
155 deg. F (68 deg. C) 4 hours
Remember, the leaner the meat, the better the jerky. Either fresh or frozen meat can be used. Meat should be trimmed of fat and connective tissue. Partially frozen meat is easier to cut into 1/4" strips, 6" long x 1" wide. Home produced jerky made of sliced meat pieces is usually marinated overnight. Make about 1/2 cup (120 ml) of marinade for each pound of meat. Drain the slices and pat them dry with paper towels. Sprinkle the meat with freshly-ground black pepper and other spices you like.
Basic jerky marinade:
(For 5-7 lb. of meat)
1 cup soy sauce
1/4 cup Worcestershire sauce
1 Tbs. powdered garlic
1 Tbs. black pepper
1 Tbs. liquid smoke (unless you are going to use real smoke!)
This amount of marinade is enough for 5-7 lb. of meat. Did you know that commercially made jerky is not marinated but mixed with salt, nitrite and spices in a vacuum tumbler before it is dried? If you wish to cook the meat to 160 degrees F (72 degrees C) as recommended by the FSIS., simply bring the marinade with strips of jerky to a boil. If you do not have enough marinade to do this, add more water.
Another solution is to make a special brine just for that purpose. Bring half of the brine to a boil. Insert the meat pieces, bring the brine to a boil and cook it for 2 minutes. Remove the strips and allow them to dry. Change the brine for the second half of meat and repeat the process.
Begin the dehydrating process immediately after cooking. Dry the meat at 130-140° F (54-60° C) until a test strip cracks but does not break when it is bent. Jerky can be dried in the sun, oven, smokehouse, or a dehydrator.
Real smoke just won`t adhere to wet meat. For this reason, jerky is always dried before being smoked. However, if you are going to smoke very thin meat strips with heavy smoke, don`t do it for too long. If the smudge is heavy and the strips are thin, more than 60 minutes might create a bitter flavor. Keep in mind that sausage meat is encased with casings, which acts as a barrier to smoke penetration. The casings contain millions of tiny holes that let the smoke in. Thin jerky cuts have no protective barrier and accept smoke rapidly. If the smoking temperature is maintained between 130-140° F (54-60° C), there is no difference between smoking and drying and it might be considered one process. Allow it to cool and then place it in a paper bag. For longer storage, seal it in a vacuum sealer.
The New Method Of Making Restructured Jerky - (from ground meat)
Grind the lean meat through 1/4" (6 mm) plate. Add all ingredients to meat and mix them together. Adding Cure #1 is a good idea, as it inhibits the growth of pathogenic bacteria. Develop the "primary bind".You want the sausage mass to feel sticky, exactly like it would appear during the sausage-making process. You may add some water to facilitate the mixing and spice distribution. Cover the meat and leave it overnight in a refrigerator.
Press the meat into flat strips using grinder attachments for making jerky or jerky gun. Place the ground meat strips on a cookie sheet. Preheat your oven to 325° F (162° C). (Boiling it might break it apart) Cooking it in an oven or in a smokehouse is the preferred method. Heat to 160° F (72° C) internal meat temperature.
Begin dehydrating immediately after cooking. Dry it at 130-140° F (54-60° C). Place the strips close together, but not touching. Jerky is done when a test strip cracks but does not break when it is bent. (about 8-10 hours). Next, apply the smoke. If the smoking temperature is maintained between 130-140° F (54-60° C), there is no difference between smoking and drying, and it might be considered one process. Allow it to cool and then place it in a paper bag. If it loses moisture too rapidly, place it in a jar with several holes punched in the lid. Place it in the refrigerator. For longer storage, use a vacuum sealer.
If you make jerky from wild game, be sure to pre-cook it to 165° F (74° C). Game meats, especially bears, are often infected with trichinae
and other parasites
. If the meat will not be cooked, it should be frozen according to the USDA rules. Deeply freezing meat takes care of trichinae but will not eliminate bacteria from the meat.
Please be safe folks.
And if you use a recipe from the internet... be aware that the majority of recipes on the Internet do not mention the fact that jerky should be pre-cooked in order to be microbiologically safe. Some of us will refuse to accept this fact and will never cook jerky.
If so, please use extra precautions that might be implemented to increase the safety of the product:
Good home-manufacturing practices include:
Using at least 2.5% salt.
Using sodium nitrite. (Cure #1)
Dry-curing meat for jerky.
If brine is used, add acidic ingredients into your marinade.
Don`t cut strips thicker than 1/4". The thinner the strips are, the quicker they will dry.
People who like to decrease the amount of salt or use salt substitutes should pre-cook jerky.
Ingredients that inhibit the growth of bacteria include salt, soy sauce, sodium nitrite, acidic liquids such as vinegar, lemon juice, ketchup, Worcestershire sauce, and teriyaki sauce. Jerky strips heated in marinade will dry faster. Slice meat with
the grain for chewy
jerky. Slice meat across
the grain for a more tender, brittle jerky
. Be careful when applying liquid smoke as too much may make your product bitter. Worcestershire sauce is often added to jerky marinade. It takes about 4 lbs. of fresh meat to make 1 lb. of dry jerky. Salt prevents the growth of bacteria and helps to draw the moisture out of the meat. Commercially produced and vacuum packed jerky can be stored for only one year. Home made jerky should be refrigerated and should be consumed within 1-2 months as its flavor will deteriorate in time.
Yup pards, many folks will continue making jerky without precooking meat, the way they have always done it. Whether you follow them or make jerky in accordance with the USDA regulations is up to you. Again, I'm certainly no expert, but I do strongly believe that safety is the most important step of any meat processing operation.