Drying Jerky 101
Congratulations on your move from "hobby" dryers to "commercial" dehydration! Due to the higher temperatures and air velocity, capabilities of your Harvest Saver, it is required that you periodically check your batches to avoid "cooking," or over drying.
The Harvest Saver was designed for easy cleaning and sanitation.
Jerky is a lightweight, dried meat product that is a handy food for backpackers, campers and outdoor sports enthusiasts. It requires no refrigeration. Jerky can be made from almost any lean meat, including beef, pork, venison or smoked turkey breast. (Raw poultry is generally not recommended for use in making jerky because of the texture and flavor of the finished product.) Raw meats can be contaminated with microorganisms that cause disease. These harmful bacteria can easily multiply of moist, high protein foods like meat and poultry and can cause illness if the products are not handled correctly. If pork or wild game is used to make jerky, the meat should be treated to kill the Trichinella parasite before it is sliced and marinated. This parasite causes the disease, trichinosis. To treat the meat, freeze a portion that is 6-inches or less thick at 5°F or below for at least 20-days. Freezing will not eliminate bacteria from the meat.
The following general tips for safe handling are based on USDA Meat and Poultry Hotline recommendations.
- Always wash hands thoroughly with soap and running water for at least 20-seconds before and after handling raw meats.
- Use clean equipment and utensils.
- Keep meat and poultry refrigerated at 40°F or below. Use ground beef and poultry within 2-days, red meats within 3 to 5 days or freeze for later use.
- Thaw frozen meat in the refrigerator, not on the kitchen counter.
- Marinate meat in the refrigerator. Do not save and re-use marinade.
When preparing jerky from wild game, it is important to remember that the wound location and skill of the hunter can affect the safety or the meat. If the animal is wounded in such a way that the contents of its gut come in contact with the meat or the hunter's hands while dressing the meat, fecal bacteria can contaminate the meat. It is best to avoid making jerky from this meat and use it only in ways that it will be thoroughly cooked. Deer carcasses should be rapidly chilled to avoid bacterial growth.
Consumer Education and Information Slightly Revised May 2000. Updated Compliance Guideline December 2004.
Compliance Guideline for Meat and Poultry Jerky Produced by Small and Very Small Plants.
The purpose of this document is to provide small and very small meat and poultry plants with guidance material and updated information on the safe manufacture of jerky. It is not intended to set a regulatory requirement, only guidance material. This guideline includes measures that small and very small establishments that process jerky products can use to achieve adequate lethality. These measures are described in the applicable processing step below under Lethality Compliance Guidelines for Jerky.
Meat or poultry jerky is a Ready-To-Eat (RTE), dried product that is generally considered to be shelf-stable (i.e., it does not require refrigeration after proper processing). In the early fall of 2003, FSIS found that producers of meat and poultry jerky may not be adequately processing jerky to achieve the lethality necessary to produce a safe product. FSIS identified two points in jerky processing where producers may need to do a better job.
First, jerky may not be adequately heat treated to meet the lethality performance standards if the requirement for moist cooking is not achieved. Some processors use dry heat to both heat and dry their product and, thus, do not achieve adequate lethality during the heating process because the product dries prematurely, and the lethality process stops.
Secondly, FSIS became aware that some manufacturers rely upon the maximum Moisture-Protein-Ratio (MPR), rather than water activity, for determining whether their process adequately dries the jerky to produce a shelf-stable product. While an MPR of 0.75:1 or less remains part of the standard of identity for jerky, water activity, as measured by laboratory analysis, should be used to verify that the jerky is properly dried. Water activity is a better measure of available water for microbial growth than MPR. Minimizing available water (e.g., achieving a water activity of 0.80 or less) is critical for controlling the growth of pathogens.
Lethality Compliance Guidelines for Jerky
In general, jerky processing includes slicing or forming the meat or poultry, marinating the strips, heating them, and then drying them. The purpose of the heating step is to apply a lethality treatment to kill or reduce the numbers of microorganisms so that the jerky is safe for human consumption. Drying the jerky stabilizes the final product and prevents the growth of toxigenic microorganisms such as Staphylococcus aureus. Some processors combine the heating and drying procedures into one step. However, it is critical that the heating accompanied by adequate humidity precede the drying.
If the times and temperatures in the lethality compliance guidelines are used, it is critical that the humidity criteria be rigorously followed during the cooking/heating (lethality) steps.
The following are general or common processing steps used in jerky production. Although an establishment's process may not include all these steps, the lethality treatment and drying are required to produce a safe product. The intervention step may be required for those processes that do not achieve an adequate lethality. The steps listed as heating and drying are consecutive steps. Drying should closely follow heating. Heating is used to achieve lethality of harmful microorganisms and drying is used to stabilize the product.
- Step 1—Strip preparation: Whole muscle is sliced or ground; ground product is formed into strips.( Some jerky is formed)
- Step 2—Marination: The strips are then marinated in a solution that often contains salt, sugar, and flavoring ingredients.
- Step 3—Interventions: Antimicrobial interventions before and after marinating the strips of raw product have been shown to increase the level of pathogen reduction above that achieved by heating alone. Some processes may not deliver an adequate lethality and, therefore, may require an additional intervention step to ensure product safety.
- Examples of such interventions are:
- Preheating the meat or poultry jerky strips in the marinade to achieve a minimum internal temperature of 160°F will provide an immediate reduction of Salmonella (Harrison and Harrison, 1996). Because heating in the marinade may produce an unacceptable flavor for some products, other liquids, such as water, could be used. The times and temperatures in the lethality compliance guidelines could be used for preheating in the liquid.
- Dipping the product in 5% acetic acid for 10 minutes before placing it in the marinade can augment the log reduction effects of drying but not enough to eliminate pathogens (Calicioglu, 2002 & 2003). This intervention may also result in an undesirable flavor.
- Step 4—Lethality treatment: The establishment must apply a treatment to control, reduce, or eliminate the biological hazards identified in the hazard analysis. For meat and poultry jerky, these hazards will most likely include the microbiological hazards from Salmonella spp., Listeria monocytogenes, and Staphylococcus aureus. For beef jerky, Escherichia coli O157:H7 may also be a hazard reasonably likely to occur. In recent years, several jerky products have been found to be adulterated with Salmonella and E. coli O157:H7.