Cold smoking at 52-71° F (12-22° C), from 1-14 days, applying thin smoke with occasional breaks in between, is one of the oldest preservation methods. We cannot produce cold smoke if the outside temperature is 90° F (32° C), unless we can cool it down, which is what some industrial smokers do. Cold smoking is a drying process whose purpose is to remove moisture thus preserving a product.
You will find that different sources provide different temperatures for cold smoking. In European countries where most of the 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), some books ask for 77° F (25° C). Fish starts to cook at 85° F (29.4° C) and if you want to make delicious cold smoked salmon that is smoked for a long time, obviously you can not exceed 86° F (30° C). Cold smoking assures us of total smoke penetration inside of the meat. The loss of moisture also is uniform in all areas and the total weight loss falls within 5-20% depending largely on the smoking time. Cold smoking is not a continuous process, it is stopped (no smoke) a few times to allow fresh air into the smoker.
Smoking Fermented Sausages
When smoking fermented products such as dry salami or German spreadable sausages, it is of utmost importance to keep 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 18 → 15º C (64 → 59º F), range and cold smoke < 22º C (72º F) fits nicely into this range. 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.
A quote from “The Art of Making Fermented Sausages” follows below:
“Think of cold smoke as a part of the drying/fermentation cycle and not as the flavoring step. If the temperature of the smoke is close to the fermentation temperature, there is very little difference between the two. The sausage will still ferment and the drying will continue and the extra benefit is the prevention of mold that would normally accumulate on the surface. Cold smoking is performed with a dry, thin smoke. If we applied heavy smoke for a long time, that would definitely inhibit the growth of color and flavor forming bacteria which are so important for the development of flavor in slow-fermented sausages (salamis). As drying continues for a long time and cold smoking is a part of, it makes little difference whether cold smoke is interrupted and then re-applied again.”
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 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. Smoking continues through the night. Photos courtesy 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, 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.
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 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 will slowly be acquiring a golden color along with a smoky flavor.
Cold smoking allows us total smoke penetration inside of the meat. Very little hardening of the outside surface of the meat or casing occurs and smoke penetrates the meat easily.
Hot smoking dries out the surface of the meat creating a barrier for smoke penetration.