Various methods can be used for preserving meats to eliminate the need for refrigeration. Before the use of pressure-cooking to “can” meats, meats were air-dried, cured with salt and sugar and/or a combination of smoke and heat.
Today nitrates, sodium nitrate and potassium nitrate are also added along with salt and sugar in the curing of meats. Nitrates are known to inhibit bacteria growth by reducing the oxidation process. Regular table salt also inhibits bacteria growth by drawing the moisture out of microorganism effectively destroying them. This process is referred to as “osmotic pressure”. The concept behind any curling or preservation of meats is the elimination of moisture, which bacteria need to survive and grow.
Drying Meat Using Hot Air and Wood Smoke
Drying to preserve meats has been used for thousands of years and is still used today. Drying meats using a heat source can also include smoke from a hardwood fire. Smoke adds flavor and helps prevent the growth of bacteria.
Dehydrators are typically used to make jerked meats today. The dehydrators are relatively inexpensive and make the process much faster and more efficient, and it can be done on your kitchen counter. However, you can use any heat source such as a campfire, charcoal/gas grill or your oven to dry meats. Most processes do not remove all of the moisture but enough is removed so that bacteria cannot survive.
Dried meat can be stored out of refrigeration in ambient temperatures for many months because of the low moisture content, which prevents microbial spoilage of the meat proteins. Lean cuts of meat are used for drying because fatty tissue will become rancid and this process cannot be stopped by the curing process.
Buffalo, beef, goat and game meats such as deer and antelope are ideal meats for curing. Livestock used in some regions for meat production, such as camels or yaks can also be used.
Mutton is ranked slightly lower as far as an ideal meat for curing and is not used unless no other meats are available. Pork, even from very lean muscle parts, is less suitable, because it contains higher amounts of fat, mostly invisible within the muscle cells. This would make the meat prone to oxidation and would quickly become rancid. In other words, pork has too much fat in the cells that cannot be removed prior to the curing process.
Field Expedient Method for Preserving Meats
If you are drying meats in the field, you will need to construct a rack so the meat is elevated enough so it does not cook over the heat. Build a fire and let it burn down to hot coals. Use green saplings to build a drying rack over the fire. Have some wood pieces available that can be tossed on the fire to create smoke without creating flames, you want consistent heat so adding wood will be necessary from time to time. Wet wood chips or wet chunks of wood are idea for creating smoke.
You will need to confine the heat by building a reflective shield around the fire, use tarps, ponchos or vegetation. You want enough heat and smoke to surround the meat continually while not cooking it. The ideal temperature for drying meats over an open fire is 200ᵒF (93ᵒC). The low heat will evaporate the moisture without cooking the meat and the smoke will provide a protective layer to prevent bacteria from entering the meat. The smoke will help repel insects as well.
To prepare the meats cut into thin strips and remove all fat from the meat. The meat will shrink considerably so there will be less volume after the process is done.
The longer you dry the meat the longer it can be kept. However, if it is too dry it will be brittle and difficult to eat. The strips should have resistance when you bend them but they should not break when slightly bent. If you do “over dry”, any pieces save them for making protein broths by placing in hot water and letting the meat steep for a few minutes.
To use your oven for drying meats cut the meat as described earlier, lay on baking sheets so the strips do not touch each other and set the oven for 200ᵒF (93ᵒC). Keep the oven door open a crack to allow the moisture to escape. This process depending on how much meat you have in the oven can take in excess of eight hours.
Jerky is processed in relatively the same way except in commercial production the heat is lowered to around 160ᵒF (71ᵒC). Usually meat for jerky is cut following the grain of the meat.
The meat is typically marinated in a liquid or a dry rub can be applied prior to the drying. Salt is sometimes added to help with the curing. Vinegar can be used instead of salt to inhibit bacteria growth and it is used in the making of Biltong, which is a variety of cured meats originating from South Africa. What separates Biltong other than the vinegar from other jerky is the thickness of the meat. Biltong traditionally comes in thicker cuts than does jerky up to one inch normally.
When using the hot air oven drying method, you can place the meat strips directly on the wire racks without a cooking/baking sheet to help speed up the process. This allows the hot air to circulate around the strips. The meat takes approximately 6-8 hours for a full rack.
Sun/Air Drying of Meats
While still used today in some countries, open air-drying of meats is not nearly as efficient as heat drying methods and it has certain disadvantages. One problem with this method is contamination. Insects and birds along with windblown debris can contaminate the meats while it is drying. Cheesecloth or similar material can be used along with a salt solution of 14 percent to help cure the meat and to repel insects to some extent. The meat is dipped in the salt solution and then hung vertically in most cases.
Typically, the meat is cut into strips and suspended so the air/sun can reach all sides. This method is not recommended unless you have experience with air-drying or there is simply no other method available. In many cases, the meat has to be removed at night to prevent contamination and from theft by predators. The meat must then be placed back in the sun/air the next day to finish the process. A method to prevent spoilage/contamination must be used in the overnight hours.
Salt Curing Meats
Salt in a high enough concentration can be used to draw the moisture from the cell membranes of meat by osmosis. Bacteria, which spoils meat, needs water to survive and when enough water is removed, the bacteria cannot survive. Today most people will purchase curing salts that generally contain nitrates if they want to cure a ham or make bacon for instance. Salt will draw the moisture from the muscles cells of pork whereas heat drying is not usually sufficient to evaporate or remove enough of the moisture from the muscle cells of pork. Often time’s sugar of some sort is added to the salt.
Salt curing can be an efficient method but it too has its drawbacks and the term botulism derives from the Latin term for “salt cured meats or cured sausages” in particular. Botulism by definition is caused by eating preserved foods contaminated by the botulinum organism. This is why most home curing salts purchased from a retailer will have nitrate in them to destroy the bacteria during the curing process.
The process takes time, weeks and even months in some cases and it must be done properly. It is recommended that you follow the directions carefully on the containers of curing salts. Use curing salts from a retailer instead of trying to develop your own unless you are experienced in this method. The salt concentrate should be at least 40 percent.
Canning meats, in other than a pressure cooker, that can raise the temperature of water up to at least 240ᵒF (115ᵒC) is not considered a safe method. The boiling point of water 212ᵒF (37.7ᵒC) is not considered sufficient to destroy certain bacteria than can be present in the meat.
Meats not properly processed can contain the bacterium Clostridium botulinum that causes botulism, which can be deadly. The bacteria can exist either as a spore or as a vegetative cell.
Ideal living conditions for the bacteria include moist, low acidic food, temperatures between 40 and 120ᵒF and in a low oxygen environment, below two percent. Botulinum spores are on most fresh food surfaces but they grow only in the absence of air therefore they are harmless on fresh foods.
Botulism is not usually destroyed at the normal boiling point of water and once in a low oxygen environment such as inside of a canned meat jar they can grow if not destroyed by high heat.
The meats must be processed at between 240-250ᵒF. The time to process is approximately 30 minutes for most meats packed hot and up to 90 minutes for meats packed cold in quart jars.
Hot Pack Canning
Typically, the meat is cubed to fit in quart glass canning jars and is pre-cooked until rare by roasting, or pan-frying with a small amount of cooking oil. Add one teaspoon of salt to the quart canning jars. Pack the meat into the jars leaving a one-inch space at the top.
Add up to 2 teaspoons of salt to each quart jar and then simply pack the raw cubed/ cut up meat in the jars leaving a one-inch space at the top.
Once packed it is important that you follow the pressure cookers instructions carefully. The settings will depend on the meat and your altitude.
Use approved canning jars only. You cannot repurposes mayonnaise, pickles or other type jars that had contained foods from the grocery store to can with at high heat.