Cold Smoking

Cold smoking has always been a popular topic on any meat forum. It generates a heated discussion due to people having a preconceived opinion based often on incorrect information they had found on the Internet.

What is Cold Smoking?

Cold smoking is applying smoke at a temperature below the temperature when meat proteins denature (start to cook). Crossing this temperature hardens the texture and inhibits the removal of moisture. This happens around 86° F (30° C), which may be the upper limit for cold smoking. You will find that different sources provide different temperatures for cold smoking. In European countries, where most cold smoking is done, the upper temperature is accepted as 86° F (30° C). The majority of Russian, Polish, and German meat technology books call for 71° F (22° C), and some of the best German books ask for 64° F (18° C).
Anything from 86° F (30° C) to 160° F (72° C) becomes hot smoking, although there is a less popular gray area called “warm smoke” from 87-104° F (31 – 40° C). Sausages are often preheated in a smokehouse at 115-125° F (46-51° C) without smoke until the casings are dry or at least tacky to the touch. This is known as “conditioning.” Smoking at higher temperatures is not practiced in sausage production as it will create an inferior product. However, a few known sausages are expected to be baked in the smokehouse after smoking, and in those cases, the temperature is raised to 185-189° F (85-87° C), and thin hot smoke is allowed.

Short Summary on Cold Smoking

• Cold smoking is done at 59 - 77° F (15 - 25° C).
• It is chosen for products that are not cooked but can be kept at room temperature for a long time
• The flavor of cold smoked products is more aromatic, given that the smoke had more time to penetrate all parts of the product. The proteins are not ruptured and do not melt due to a low temperature. This also allows for uniform moisture removal and perfectly controlled drying.
• Cold smoked products exhibit a dark red color, which is present even if sodium nitrate was not added.
• Cold smoking lasts from 2 - 14 days. However, it is not a continuous process. During the first two days, smoke is applied for 12 or more hours, then for 1-2 hours daily.
• The wood is burning slowly; the flames should hardly be visible, but the smoke should be moderately thick.

Note: The useful shelf life of a typical smoked and cooked sausage can be extended by cold smoking it for 1-2 hours daily for a number of days. The sausage can lose up to 20% of its weight.

Does cold smoking preserve meat?

This is a myth; smoke provides flavor, but neither cold nor hot smoking is a method of food preservation. Cold smoking indirectly contributes to preserving meat by heating the meat’s surface. However, drying (removal of moisture) preserves the meat. United States Department of Agriculture (USDA) states: “ A potentially hazardous food does not include …a food with a water activity of 0.85 or less.” Water activity (Aw) indicates how tightly water is bound inside a product. It does not specify how much water there is, but how much water is available to support the growth of bacteria, yeasts, or molds. It should be noted that applying smoke creates hostile conditions for the development of microorganisms; however, this is limited to the surface of the meat only. Drying is what preserves food, not smoking. The best definition of cold smoking is drying with smoke. It must be stressed here that cold smoke is not a magic wand that will perform miracles and immediately preserve meat. Applying smoke for a day or two will not preserve the meat unless the slice of meat is extremely thin. Dry salami is considered microbiologically safe after losing around 33% of its original weight. The same reasoning applies to cold-smoked products; they must lose enough moisture to be considered safe. The bigger the meat piece, the more time it needs to dry.

Why did we cold-smoke meat?

Pigs were slaughtered in Europe in the wintertime. However, the harsh climate was why smoking became more popular in Northern countries. A large pig weighed 300 lb, and most of that meat needed to be preserved, which was a problem, given that electricity was not available yet. The man knew that salted meat could be preserved after a long period of cold smoking. However, he was not aware yet that not dry out smoking but the heat from slowly burning wood was responsible for preserving meat. You can wash the clothes and hang them outside at freezing temperatures, and they will dry as long as there is some wind. In the Arctic and Subarctic regions of North America, Russia, and Greenland, Inuit people preserved fish by drying it in the sun and wind on racks made of poles or skin thongs. This method is still used today in many Arctic communities. To make it short, the drying was what preserved the meat. If our ancestors had known electricity, would they have gone through the trouble of smoking/drying meat for weeks? They were smart people; they would do what we do today: hot-smoke the meat, cook it, and store it in the refrigerator.

Cold smoking does not need to be a continuous process

In the past, in Europe and early America, there were large communal smokehouses where meat products hung six feet above the slow-burning fire, and the smokehouse also acted as a storage facility. The fire was maintained during the day and was usually unattended at night; it simply died out and was restarted in the morning by adding wood to still-hot embers. And if it died out, a new fire would be started. Remember that the smoke accounts only for a fraction of the time a burning log provides. In the spring and the fall, the products can be kept in a smokehouse all the time provided that the temperatures are low. The same applies to wintertime, but we do not have the products to be frozen. That requirement depends on the climate in which smoking takes place.

Wood for cold smoking

Dry hardwood is best for cold smoking. Soaking chips in water beforehand is not a good idea, as this introduces more moisture into the chamber. The purpose of drying is the removal of moisture and not bringing in more of it. People imagine that soaking wood chips in water generates more smoke, but this is incorrect. They generate a lot of visible steam vapor that will soon disappear. When heat is applied to wood, the moisture starts to evaporate. Even a well-seasoned wood still contains about 20% of the moisture that has to go away. Then, as the wood dries out, it reaches a much higher temperature, and at that stage, it generates smoke. It lasts a certain time, and then the wood becomes very dry and bursts into flames, resulting in a significant temperature jump. This is why meat products were hung six feet or higher above the fire unless there was a separate fire pit connected with a smokehouse with a pipe or a trench. To make it short, the meat only received a thin, cold smoke for part of the day. Burning wood logs differs from burning wood pellets or sawdust in modern smokers, which continuously produce smoke. Meats can be cold smoked at night in winter, even in southern states of the USA, but they must be moved to the cooler or refrigerator in the morning when the temperature goes up; then, the process is repeated on the second night.

Is cold smoking popular today?

It is on the decrease as it is time-consuming, and we can hot-smoke products in a few hours and keep them refrigerated. German (Mettwurst, Teewurst) and Polish (Metka) cold smoked spreadable sausages, which must be refrigerated as they are neither dried nor cooked. Being raw meat, they have a unique taste and soft texture and must be consumed within a week. Lox (smoked salmon) is smoked with cold smoke for an extended period of time. Applying hotter smoke (over 84° F, 28° C) will just cook the fish; the flavor and texture will change, and we will not be able to slice it so thin anymore. Cold smoking is a slow process, and the hams, which lend themselves perfectly to this type of smoking, can be smoked from 2 to even 6 weeks. During smoking, they acquire a golden color along with a smoky flavor.

Do cold-smoked products taste better?

No, they don’t; at least, most people think so. They are saltier and have a different taste; after all, it is uncooked meat. Very few products are commercially cold-smoked nowadays; the most known is lox (smoked salmon), which can be sliced paper thin. If it were hot-smoked, the flesh of the fish would flake and crumble, and the slices would fall apart. Cold-smoked meats are saltier and exhibit a firm texture. In the case of sausages, there is not much difference between cold smoked sausage that was cold smoked/dried for a long time and traditionally dried salami, as the manufacturing process is basically the same. Those products are not cooked but are considered safe to eat when they lose about 33% of their original weight. Of course, the cold smoked sausage will have a smoky flavor, and Italian salami or Spanish salchichón will not. However, Hungarian salami is usually smoked.
Italians and Spaniards never liked smoked products as they had the perfect climate for drying meats with steady prevailing winds at the right temperature. Those who lived up in the mountains needed to warm up the smokehouse chambers with fire; hence, some products were smoke-dried.

Smoking Fermented Sausages

When smoking fermented products such as dry salami or German spreadable sausages, it is of utmost importance to keep the smoke temperature down. German meat technology books recommend applying cold smoke below 18° C (64° F) for about 3-4 days. Slow-fermented dry sausages and fermented spreadable sausages can be cold smoked only. The initial drying temperature for fermented sausages falls into the 18 → 15º C (64 → 59º F) range, and cold smoke < 22º C (72º F) fits nicely into it. Then drying continues at temperatures below 15º C (59º F). To sum it up, the length of cold smoking is loosely defined, but the upper temperature should remain below 22º C (72º F). Unfortunately, this rule puts some restraints on making slow-fermented sausages in hot climates for most of the year unless some cooling methods are devised. Fermented sausages are known to develop mold during the fermentation and drying stages. Applying cold smoke for a few hours will prevent mold growth for some time only. Then, the procedure will have to be repeated.

Smokehouse

In XVIII century brick built smokehouses a fire was started every morning. It smoldered as long as it could and if it stopped, it would be restarted again the following morning.

Cold smoked meats prevent or slow down the spoilage of fats, which increases their shelf life. The product is drier and saltier, with a more pronounced smoky flavor and a very long shelf life. The color varies from yellow to dark brown on the surface and dark red inside. Cold-smoked products are not submitted to the cooking process. If you want to cold smoke your meats, bear in mind that with the exception of people living in areas with a cold climate like Alaska, it will have to be done in the winter months, just as it was done 500 years ago.

Cold smoking at its best; using split seasoned wood logs. Smoking continues through the night. Photos: Waldemar Kozik.

Using dry wood is of utmost importance when cold smoking. It is recommended to keep wood chips in a well-defined single pile as they will have less contact with air and thus will smoke better without creating unnecessary flames and heat. By following these rules, we achieve 75-85% humidity, creating the best conditions for moisture removal. Once the moisture content drops low enough, the salt present in the meat will further inhibit the development of bacteria, and the products can hang in the air for months, losing more moisture as time goes by.