There are two kinds of smoked salmon: hot-smoked and cold-smoked. Most people are familiar with the hot-smoked variety. It has a flaky texture and a refrigerated shelf life of about a week. Cold-smoked is the traditional Scandinavian style of smoking. Cold-smoked salmon has a texture similar to ham, which is not surprising considering the similarities of processing. Refrigerator life can be anywhere from one week to six months, depending on how long the salmon has been cured and smoked. Curing and smoking is a form of food preservation; the longer the salmon is processed, the greater its shelf-life.
Two factors affect the moistness of the smoked salmon: amount of oil present in the fresh fish and the length of time it is smoked. Spring run Chinook is the oiliest salmon and produces a very rich and moist smoked product. Smoked salmon of either hot- or cold-smoked variety is ready to eat. It does not need cooking, though hot-smoked salmon is a wonderful addition to scrambled eggs or with an Alfredo sauce over fettucine and cold-smoked salmon can be substituted for ham to make an alternative to traditional eggs benedict. Smoked salmon sushi uses cold-smoked salmon.
Other write-ups in this node describe the hot-smoked method of preparation, in which the smoker produces a certain amount of heat. I will describe traditional Scandinavian style of cold-smoking, employed by Josephson's Smokehouse in Astoria, Oregon, the only commercial cold-smoker on the West coast of the United States. The Josephsons family has been smoking salmon for retail and wholesale since 1920.
Filleted sides of salmon are salted on both sides, then laid in wax-coated barrels to cure. For the lighter "lox-style" of smoked salmon, the sides are cured for one week. For the traditional Scandinavian style, the sides are cured for up to six weeks. After curing in the barrels, the sides are rinsed to remove excess salt and hung on hooks in the smokehouse. Again, the length of time spent in the smokehouse depends on the type of smoked salmon being produced. Lox-style smoked salmon is smoked for only about a day; smoked salmon jerky strips are smoked for upwards of a week. The smokehouse is kept at a steady 55 degrees Fahrenheit (hence "cold-smoked") while alder wood, in abundance on the north Oregon coast, is burnt to produce smouldering smoke which gives the salmon its distinct smoked flavour. After the salmon sides comes out of the smokehouse, they may be cut into chunks, sliced or left as an entire side, and packaged. The salmon flesh retains its bright color, enhanced by the smoking process, without artificial coloring.
IMHO, this is without question the best smoked salmon available. The lox-style, made from Chinook or King, salmon is less salty than East coast nova lox and has a slight smoky flavor. Sockeye or Red salmon from Alaska produces a firm-fleshed product with a unique flavor. Coho or silver salmon is a less oily alternative to the popular Chinook.
Disclaimer: I worked for Josephsons over summers in the early 1980s and we have remained friends ever since. I want you all to buy Josephsons smoked salmon, available by mail order and through their web site www.josephsons.com.
Please note: Smoked salmon is not raw - it has been cured. You cannot eat raw salmon. It will make you very sick. When you order "fresh" salmon at a sushi bar, it is not fresh. It has been freezer-cured; it has been frozen and thawed.