Jerky is meat that has been cut into strips trimmed of fat, marinated in a spicy, salty or sweet liquid and then dried with low heat (usually under 70°C/160°F) or occasionally salted and sun-dried. The result is a salty, stripped, semi-sweet snack that can be stored without refrigeration. Jerky is an early application of food preservation techniques.
Drying has always been a common way to preserve meat. By drying in thin slices in the sun and wind next to a smoky fire, the meat is protected from insects that would otherwise lay eggs in the raw meat. Ancient peoples—for example, the Inca—prepared jerky from the animals they hunted or husbanded.
In present-day factories jerky ovens are made of insulated panels. Inside these large ovens are many heater elements and fans with exhaust ports to remove moisture-laden air. The combination of fast moving air and low heat dries the meat to the desired moisture content within a few hours. The raw marinated jerky strips are placed on racks of nylon screens which have been sprayed with a light vegetable oil to allow the meat to be removed easily. The screen trays are placed closely in layers on rolling carts which are then put in the drying oven. Some other form of preservative in addition to the drying process is often used in the preparation of jerky. Smoking was the traditional method, as it preserved, flavored, and dried the meat simultaneously. Salting is the most common method used today, as it both provides seasoning to improve the flavor as well as preserve the meat. While some methods involve applying the seasonings with a marinade, this can increase the drying time by adding moisture to the meat.
Some jerky products are made naturally or organically. Natural and organic jerky makers use meat from animals which are raised on organic feed and minimally processed. These animals are not treated with hormone enhancement and are not fed animal by-products. Additionally, these jerky products do not contain MSG, preservatives, artificial flavors, or erythorbate and are gluten free.
After the jerky is dried to the proper moisture content to prevent spoilage, it is cooled, then packaged in re-sealable plastic bags, either by nitrogen gas flushed or vacuumed packed. In order to prevent spoilage, the sealed packages often contain small pouches of oxygen absorber. These small packets are filled with iron particles which work to retain oxygen and excess moisture that may be present, or from air introduced after the seal is broken (due to partial consumption).
Most of the fat must be trimmed off prior to drying the meat, as fat does not dry, thus creating the potential for spoilage as the fat becomes rancid. (modern vacuum packing and chemical preservatives have served to help prevent these risks).
Because of the necessary low fat and moisture content, jerky is high in protein. A 30 g (about 1 oz) portion of lean meat, for example, contains about 7 g of protein. By removing 15 g of water from the meat, the protein ratio is doubled to nearly 15 g of protein per 30 g portion. In some low moisture varieties, a 30 g serving will contain 21 grams of protein, and only one gram of fat. This leads to the high price of such brands of jerky, as it takes 90 g of 99% lean meat to generate that 30 gram serving.
There are many products in the marketplace which are sold as jerky which consist of highly processed, chopped and formed meat, rather than traditional sliced, whole-muscle meat. These artificial products, with their far higher fat and water content, often include chemical preservatives to prevent spoilage.
A typical 30 g portion of jerky contains 10-15 g of protein, 1 g of fat, and 0-3 g of carbohydrates. Since traditional jerky recipes use a basic salt cure, sodium can be a concern for some people. A 30 g serving of jerky could contain more than 600 mg of sodium, which would be about 30% of the recommended USRDA.
Unpackaged fresh jerky made from sliced, whole-muscle meat has been available in specialty stores in Hong Kong at least since the 1970s. The products are purchasable by kilograms, and customers choose from 10 to 20 types of meat used to make the product. Some are sold in strands instead of slices. Macau has opened up numerous specialty shops also, many of which are franchise extensions of stores from Hong Kong. Compared to the sealed packaged versions, unpackaged jerky has a relatively short expiration date.
This type of jerky has also become very popular in convenience stores in the USA. This product is called "slab" jerky and is usually marketed in plexiglass containers.
A similar product is made from processed meat, is often labeled as jerky. This product is also widely available, and generally much cheaper, in general interest stores such as supermarkets and convenience stores.
In addition to being quite common in the United States and Canada, jerky is also gaining popularity in supermarkets, convenience stores and online retailers. In Australia and New Zealand, jerky products are available and becoming more common. They are carried by some major supermarkets, and now also smaller stores.
Since 1996, jerky has been selected by astronauts several times for space flight due to its light weight and high level of nutrition.