Smoked salmon is a preparation of salmon, typically a fillet that has been cured and hot or cold smoked. Due to its moderately high price, smoked salmon is considered a delicacy. Although the term lox is sometimes applied to smoked salmon, they are different products.
In North America, smoked salmon is likely to be sliced very thinly and served on bread with cream cheese or with sliced red onion, lemon and capers. In British Columbia smoked salmon may also be fillets or nuggets, including hickory-smoked varieties and candied salmon (smoked and honey-glazed, also known as "Indian candy").
In Europe, smoked salmon may be found thinly sliced or in thicker fillets (such as "tsar fillet") or sold as chopped "scraps" for use in cooking. It is often used in pâtés, quiches and pasta sauces. Scrambled eggs with smoked salmon mixed in is another popular dish. Smoked salmon salad is a strong-flavored salad, with ingredients such as iceberg lettuce, boiled eggs, tomato, olives, capers and leeks, and with flavored yogurt as a condiment.
Slices of smoked salmon are a popular appetizer in Europe, usually served with some kind of bread. In the United Kingdom they are typically eaten with brown bread and a squeeze of lemon; in Germany they are eaten on toast or black bread.
Smoked salmon is sometimes used in sushi, though not widely in Japan; it is more likely to be encountered in North American sushi bars. The Philly Roll combines smoked salmon and cream cheese and rolls these in rice and nori.
In the Pacific, a variety of salmon species may be used. Because fish farming is prohibited as a matter of state law, all of Alaska's salmon species are wild Pacific species. Pacific species of salmon include chinook ("King"), sockeye ("red"), coho ("silver"), chum (keta), and pink ("humpback").
Most smoked salmon is cold smoked, typically at 37 °C (99 °F). The cold smoking does not cook the fish, resulting in a delicate texture. Although some smoke houses go for a deliberately 'oaky' style with prolonged exposure to smoke from oak chips, industrial production favours less exposure to smoke and a blander style, using cheaper woods.
Originally, prepared fish were hung in lines on racks, or tenters, within the kiln. Workers would climb up and straddle the racks while hanging the individual lines in ascending order. Small circular wood chip fires would be lit at floor level and allowed to smoke slowly throughout the night. The wood fire was damped with sawdust to create smoke; this was constantly tended as naked flames would cook the fish rather than smoke it. The required duration of smoking has always been gauged by a skilled or 'master smoker' who manually checks for optimum smoking conditions.
The smoking process has changed over the years and many contemporary smokehouses have left the traditional methods using brick kilns behind in favour of commercial methods. In fact, only a handful of traditional smokehouses remain such as Stornoway Fish Smokers and John Ross Jr (Aberdeen)Ltd. whose kilns date back to 1857 and have been listed by Historic Scotland.
Smoked salmon was introduced into the UK from Eastern Europe. Jewish immigrants from Russia and Poland brought the technique of salmon smoking to London's east End, where they settled, in the late 19th century. They smoked salmon as way to preserve it as refrigeration was very basic. In the early years, they were not aware that there was a salmon native to the UK so they imported Baltic salmon in barrels of salt water. However, having discovered the magnificent wild Scottish salmon coming down to the fish market at Billingsgate each summer, they started smoking these fish instead. The resulting product took off as a gourmet food and was introduced into the fine dining and delicatessen trade and indeed became one of the most popular gourmet foods across the western world through the 20th century.
Irish and Scottish smoked salmon is considered a delicacy, even with increased availability since the advent of fish farming from the 1970s. Smoked wild salmon is still available, but in Europe is very rare and very expensive and usually only available from specialist dealers. In North America, Alaskan wild salmon is commonly smoked, and many Alaskans have their own smoker or even a small smoke house.
The Northwest Indian Tribes and Alaska Natives have a cold smoking style that is wholly unique, resulting in a dried, "jerky-style" smoked salmon. In the Pacific Northwest this style of salmon has been used for centuries as a primary source of food for numerous Indian tribes. Traditionally smoked salmon has been a staple of north-western American tribes and Canadian First Nations people. To preserve indefinitely in modern times, the fish is typically pressure-cooked.
Commonly used for both trout and salmon, hot smoking 'cooks' the salmon making it less moist, and firmer, with a less delicate taste. It may be eaten like cold smoked salmon, or mixed with salads or pasta. It is essential to brine the salmon sufficiently and dry the skin enough to form a pellicle prior to smoking. Without a sufficient pellicle, albumin will ooze out of the fish as it cooks, resulting in an unsightly presentation.
There are three main curing methods that are typically used to cure salmon prior to smoking.
- Wet brining: Brining in a solution containing water, salt, sugar, spices, with (or without) sodium nitrite for a number of days.
- Dry curing: This method is a traditional method typically used in Europe, in which salmon fillets are covered with a mix of salt and sugar. Traditional London Cure smoked salmon uses salt only and this is the historic approved method. Sugar in the cure is used to sweeten less fresh fish, rebalance too much smoke and also retain moisture allowing producers to sell water for the price of salmon. It also helps artificially extend the shelflife. Ideally it should be avoided. Dry curing produces a drier, silkier product and typically is faster than wet brining.
- Injection: This is the least typical method as it damages the delicate flesh of salmon. This is the fastest method of all as it injects the curing solution — hence allowing a faster cure throughout the flesh. The resulting flesh is quite wet and slimy and does not result in a high grade smoked salmon.
The proteins in the fish are modified (denatured) by the salt, which enables the flesh of the salmon to hold moisture better than it would if not brined. In the United States, the addition of salt is regulated by the FDA as it is a major processing aid to ensure the safety of the product. The sugar is hydrophilic, and also adds to the moistness of the smoked salmon. Salt and sugar are also preservatives, extending the storage life and freshness of the salmon.
In the UK, "Scottish smoked salmon" is sometimes used to refer to salmon that is smoked in Scotland but sourced from elsewhere. This is despite Food Standards Agency recommendations that such salmon be described as "Salmon smoked in Scotland" instead. Labelling must also include the method of production ('farmed', 'cultivated', 'caught').