The basic principal of cold-smoking (hot-smoking involves direct heat and higher temperatures) is to generate smoke far enough away from the food being smoked that it flavors the meat without cooking it. Moving the smoke from fire to smokehouse is usually managed by making the fire lower than the smoker and having an opening at the top to draw air. A smoker can be as simple as a metal drum with top & bottom removed, a covered trench in the ground, and a campfire.
Why smoke food? Here’s the opinion of one aficionado:
Smoking offers many improvements for meat. Besides enhancing the taste and look, it also increases its longevity, and helps preserve the meat by slowing down the spoilage of fat and growth of bacteria. Smoking meat longer leads to more water loss, and results in a saltier and drier product, which naturally increases its shelf life. Man discovered that in addition to salting and curing meat with nitrates, smoking was a very effective tool in preserving meats..
The advantages of smoking meat are numerous. Smoking:
Kills certain bacteria and slows down the growth of others
Prevents fats from developing a rancid taste
Extends shelf life of the product
Improves the taste and flavor
Changes the color; they shine and simply look better
Smoked fish develops a beautiful golden color. The meat on the outside becomes a light brown, red, or almost black depending on the type of wood used, heating temperatures, and total time smoking. Originally, curing and smoking was used solely for preservation purposes; today it’s done for the love of its flavor.
For a more technical treatise on the art of smoked meatses, check out this online publication Curing and Smoking Meats for Home Food Preservation
from National Center for Home Food, University of Georgia.
Here’s an above-ground, all-metal smokehouse set up. There are lots of pictures and inspiration at this website, including a a smoker made from a trench and tree stump that has been in use for 20 years.
Connecticut State Department of Agriculture.