In 1710, the remains of the Danish fleet returned from the Battle of Køge Bay to Copenhagen. The crews and officers were deeply unhappy, not only because their mission had failed nor even that the flagship Dannebrog had been lost. No, their complaint was that a quarter of the crew had been sick before they even sailed, and many had died of illness at sea before they ever met the Swedes. The admiral blamed the skibsøl—literally, “ship’s beer”—which was an important part of the fleet’s provisions.
The navy’s commissar-general investigated the issue, and he found that throughout the year there had been many examples of skibsøl being found spoiled and returned to the brewers. The returned beer wasn’t merely sour—it was foul. His report was part of a long discussion that had already run for many decades about how to ensure a reliable supply of skibsøl that did not go bad.
People pointed to various causes of the problem: The beer was too weak, the wood for the casks was too fresh, or the casks had been washed in seawater, and so on.
Skibsøl was very much part of the provisions of Danish sailors at the time, who were by regulation supposed to receive three quarts of skibsøl daily—that’s roughly three liters of beer, per man, per day. It’s just as well that the skibsøl was relatively low in alcohol.
The Danish ship Dannebrog caught on fire in the “Battle of Køge Bay” (1710) by Christian Mølsted
Dark & Smoky: A Rough Sketch
Although the style has been almost completely forgotten today, skibsøl is a long-lived tradition. Already in the 18th century—and probably earlier—it was a fairly well-defined type of beer. The oldest written descriptions we have of how it was made are from the late 18th and early 19th centuries, so I rely on those for this description. The beer eventually lost its role as a provision beer of military importance, and brewers somewhat modernized how they made it. However, its basic outlines appear to have remained much the same.
The malt for skibsøl was barley, dried in a kiln known as an earth-kiln (jordkølle), which was very similar to the såinn used in Stjørdal in Norway as well as the kilns used by the Austrian steinbier brewers (see The Cult of the Kiln and Fire and Brew-Stone). The malt was dried over a fire, which blazed in a brick-lined chamber on the lowest floor. Its heat and smoke rose through a floor of perforated planks to dry the malt lying on top. This floor sloped up toward the middle, rather like a house roof. The smoke finally made its way out of a chimney in the gables at the opposite end from the fireplace.
In other words, skibsøl must have been powerfully smoked, rather like stjørdalsøl and steinbier—although, in this case, mainly with beechwood. However, ash, willow, birch, alder, and maple could also be used as firewood, and the wood used would of course affect the flavor.
Skibsøl appears to have been consistently smoked throughout its entire existence, and some claim this is because smoked beer keeps better. It may be that the Danish navy believed this, and that’s why they used smoked malts. Many sources also say that the sailors at the time believed that darker beer was stronger, so the color added by smoking the beer helped keep the sailors satisfied that they were getting strong beer.
The actual brewing process most likely was a step mash, although at what temperatures is unclear. After runoff, the brewers boiled it for three to four hours, which would have concentrated it and added caramel flavors.
Brewers boiled the hops in water separately—i.e., a hop tea—and then mixed that into the beer. What hop varieties they used is unknown, but it appears to have been a mix of Danish-grown and imported (mostly German) hops. Any hop aroma would have been closer to Noble than anything modern.
After boiling, brewers cooled the wort in a wide, shallow basin very much like a coolship, as was common at the time. The brewers pitched the yeast when the wort was “milk-warm,” meaning roughly body temperature. Thus, it’s unlikely to have been anything like modern ale yeast and must have been something more like kveik and other farmhouse yeast. Brewers apparently switched to more modern ale yeasts in the 20th century, but it’s not clear which strains they used.
The exact strength is difficult to determine. At one point, a royal decree required a proportion of three barrels of skibsøl from one barrel of malt. At normal attenuation and an estimated 50 percent efficiency from old-style malts, it may have been about 5 percent ABV—however, it’s more likely that skibsøl was usually weaker than that for several reasons.
More Hops, Less Alcohol
Hopping rates are not known in numbers, but sources widely agree that skibsøl was strongly hopped, and they are very clear on why: so that the beer would keep and not spoil. If that makes skibsøl sound a bit like IPA, realize that a relatively weak, highly smoky beer fermented with farmhouse yeast must have been quite different.
IPA was not a particularly strong beer for its time, even if it was stronger than skibsøl. Anyway, longer keeping wouldn’t have been why IPA was brewed stronger. In general, beers brewed for export were relatively strong simply because this gave the greatest return on the cargo. So, it was really the hops that did the job of preserving both IPA and skibsøl, more than the alcohol.
Most likely, naval captains didn’t particularly want to give their crews strong beer, with all the consequences that might have. It seems likely that naval discipline was the principal reason that skibsøl was relatively weak. Also, it apparently was common for unscrupulous brewers to supply under-strength skibsøl, giving the officers a couple of casks of stronger beer so they would accept the deficient skibsøl without complaint.
The Significance of Skibsøl
The proof that skibsøl was seen as a resource of real military importance is the amount of attention the Danish bureaucracy paid to it. The king even established a large brewery of his own, known as Kongens Bryghus (The King’s Brewhouse) specifically to supply the fleet with beer. In the 18th century, the king reorganized the entire brewing industry in Copenhagen into an absurd monopoly scheme that protected brewers against bankruptcy. Why? To ensure that the city could always produce enough skibsøl for the fleet. This scheme gave the brewers no incentive at all to produce quality beer, which made the people of Copenhagen hate it with a passion.
Lager beer came to Denmark in the mid-19th century, and it quickly became very popular, displacing earlier Danish beer styles based on ale yeast. Skibsøl was among the many brewing traditions to suffer under the onslaught of lager—yet it lingered on through the 1980s. The last commercial Danish skibsøl went out of production in 1991.
By the 20th century, skibsøl was still dark, strongly hopped, and powerfully smoked. It typically was about 2.25 to 2.8 percent ABV.
To add some context, skibsøl was only one member of a larger Scandinavian family of commercially brewed beers in the 18th and 19th centuries that were all dark, sweet, and relatively weak. This included the Danish hvidtøl, the Norwegian pottøl, and the Swedish svagdricka. (Note: Swedish commercial svagdricka and farmhouse svagdricka are not the same thing.)
Skibsøl didn’t die out completely. In 1994, a small Danish brewery started making it again. This was Refsvindinge Bryggeri, a family-owned brewery in Nyborg, on the east coast of the island of Funen. The brewery dates to 1885, and for much of its history it brewed beers such as skibsøl. In fact, it only began brewing modern lagers and ales in the 1980s.
Last year, Refsvindinge received a diploma from the Danish Academy of Gastronomy for their skibsøl. The brewery’s “beautiful renewal of a classic product” was given as the rationale for the award.
Receiving the diploma, brewery director Ellen Skjødt Rasmussen said they brew the skibsøl “not because it makes a lot of money” but because of its historical importance. In fact, the beer sells only a few hundred bottles a month—yet to make it in the traditional way, they buy local barley and malt and dry it themselves to get the right smoky flavor. It’s clear that there’s real determination behind the brewery’s effort to keep skibsøl alive.
So, while you can still taste this classic, historical Danish style of beer, there’s a real sense that its time may be running out.
Buy it—or brew it—while you can.