Liquid sweeteners are often used for baked goods like gingersnaps, in candies, or as a caramelization agent for sauce reductions, or in cabbage rolls. Look at any Scandinavian recipe that requires liquid sweetener and chances are that you'll be asked to use either "light syrup" (in Swedish, "ljus sirap) or "dark syrup" (mörk sirap). It can be hard to get Scandinavian siraps in the United States, and they're not like maple syrup. Siraps are similar to British golden syrup and treacle, and not wildly different from American molasses, made from sugar.
History of Scandinavian Sirap
According to the website Swedishfood.com, "Although Sweden's first sugar refinery was opened in Stockholm in 1647, sugar was originally a luxury good only enjoyed by the aristocracy. By the late 1800s, most Swedes had started to enjoy sugar and syrups and so, at the start of the 20th century, there were 10 sugar refineries in Sweden. In 1907 they formed a company, Svenska Sockerfabriks AB (SSA). In 1987 the company changed its name to Sockerbolaget AB and in 1995 the name was changed again, this time to Danisco Sugar AB. In 2000 the brand name for consumers changed to Dansukker."
History of Lyle's Golden Syrup
During the process of refining sugar, a light syrup is created. This syrup used to go to waste, until chemist Charles Eastick perfected a way to refine the leftover syrup into a preservative and sweetener. Eastick worked for Abram Lyle & Sons, who began to market the product in 1885 under the name Golden Syrup. A deeply religious man, Abram Lyle chose the somewhat odd emblem of a dead lion covered in bees for the iconic image on golden syrup tins. The tins also bear the company slogan "Out of the strong came forth sweetness." In 2006, the Guinness Book of World Records deemed it Britain's oldest brand. The design of the tins has remained almost completely unchanged since 1885.
Where to Buy Light and Dark Syrup
Both light syrup and dark syrup are distributed by the Swedish Dan Sukker company; you can order them online from Scandinavian suppliers such as Scandinavian Specialties, or from Amazon. It's also sometimes available in stores that specialize in European foods or products, like Marina Market.
Substitutes for Scandinavian Light and Dark Syrup
Scandinavian light and dark syrups, unlike American "light" and "dark" corn syrups, are processed from sugar beets rather than corn. Thus, in most recipes calling for "dark syrup," one can generally substitute light molasses. The Swedish dark syrup is a bit sweeter and less bitter than American light molasses, but the taste is close enough that this substitution works well. Another option is to mix Lyle's dark treacle syrup with Lyle's golden syrup for a 50/50 blend.
Light syrup, however, really doesn't have a good U.S. equivalent. It's fairly thin (as syrups go) and sweet, with the distinctive flavor of brown sugar. Although you can substitute corn syrup in a pinch.