Sahti: Finland’s Famous Farmhouse Ale

Unlike many other farmhouse brewing traditions, sahti is relatively well known and widely produced in its homeland. In the wider beer world, however, it’s frequently misunderstood.

Lars Marius Garshol Aug 21, 2023 - 11 min read

Sahti: Finland’s Famous Farmhouse Ale Primary Image

Photo: Matt Graves

Brewers and beer enthusiasts have known about sahti for a few decades now, even if it’s been hailed superficially as “an ancient beer” or “the oldest beer style.” Today, it’s easy to describe it accurately because we have more context: Sahti is a Finnish style of farmhouse ale, brewed by Finnish farmers for their own consumption over many, many centuries.

Today, sahti is still quite widely brewed out in the Finnish countryside, both on farms and in ordinary private homes. It’s impossible to say exactly how many brewers there are, but there are certainly many hundreds of them, spread out in a broad belt that runs from Finland’s western coast through the center of the country.

Most of them brew sahti for their own consumption, although some also sell it illegally. There are also several commercial sahti brewers, as well as some smaller brewers who sell wort that their customers then ferment into beer themselves. This little trick avoids all the difficult alcohol and tax laws because what is sold is entirely alcohol-free.

Unlike most farmhouse-ale styles, sahti is under no threat of extinction. In fact, it’s thriving. What it has in common with most farmhouse ales, however, is that it’s very different from modern beer.


Visually, it seems normal: Its hazy, opaque body ranges in color from deep yellow to brown, although the head is usually minimal. On the palate, it’s sweetish, full-bodied, malty, and sometimes even quite viscous, but at the same time it’s surprisingly easy-drinking and balanced. The juniper-derived bitterness helps to balance it, as does the sharpish texture from raw (unboiled) wort. On top of that comes a fruity character from the yeast, often more than you would expect. And, like all true farmhouse ales, sahti has very little carbonation.

The best examples are seductively smooth and easy to drink yet rich in character from the brewing process, the combination of grains, the juniper, and the yeast. A well-brewed sahti is magnificent but should be enjoyed with caution. The beer is usually 8 to 10 percent ABV—but the flavor tends to hide this completely, so the strength can sneak up on you. Many people have learned this to their chagrin.

From Left: Eila Tuominen ladling the mash into the kuurna, in Pertunmaa; Seppo Lisma, wearing a traditional birch bark hat, stirring his mash in Ruovesi

Tradition and Composition

Historically, the farmers malted their own grains, drying them in the sauna—Finland’s traditional steam house. In the old days, saunas were wood-fired and smoky, so the malt also would have been smoked to some degree. Today, however, sahti is not a smoked style of beer. Most brewers buy a ready-made product, called Sahti Malt, from locally based Viking Malt, although they often mix that with other malts, too. (If you can’t get Viking’s Sahti Malt, the Finnish beer writer Mika Laitinen—author of Viking Age Brew: The Craft of Brewing Sahti Farmhouse Ale—recommends replicating it with three parts pilsner to one part Munich.)

Barley malt dominates the grist, and brewers in the eastern half of the sahti area use that exclusively. In the western parts, brewers also use rye malts, both pale and dark. There, it’s not unusual for them to use up to 25 to 40 percent rye malt. As rye malt, and especially dark rye, can be very flavorful, these sahtis can have strong, spicy rye flavors and even some toasty character from the dark malt. Many brewers also use unmalted rye, which lends the sahti more viscosity.


The process varies from brewer to brewer, but almost all start with a very long step mash, gradually adding more and more hot water (or juniper infusion) to the mash. Usually, they transfer the mash to the kettle and heat it there. Some merely go to 185–194°F (85–90°C), while others boil the mash for an hour or more. Such boils tend to be vigorous, with the occasional gob of mash flying out of the kettle to spatter the walls.

However—you may be thinking—isn’t a boiled mash difficult to lauter? Maybe it would be with modern gear, but farmhouse brewers don’t use that. The classic Finnish lauter tun is a trough about two meters long and 50 cm wide (roughly 6.5 by 1.5 feet), with a hole at one end to run off the wort. This is known as a kuurna (with a long “oo” sound and the inimitable rolling Finnish “r”). The actual filter is usually some juniper branches on the bottom of the trough, with a row of wooden spiles above. The spiles serve as a false bottom, beneath which the wort can flow. Because the mash is spread relatively thinly in this long, wide, shallow vessel, and because the filter is so coarse, lautering a boiled mash—even when including notoriously viscous rye—does not lead to a stuck mash. Many brewers recirculate the wort through the kuurna several times until it clears.

Even if the mash is boiled, traditional sahti brewers do not boil the wort at all—so sahti is a raw ale, like Norway’s kornøl and Estonia’s koduõlu. However, because the mashing and grains are so different, it is clearly distinct from those styles. The yeast is also different, as we’ll see.

Many sahti brewers use hops today, but many still don’t. Hops started taking over and becoming dominant as the spice in beer about a millennium ago—but the process was slow, and in Finland, it’s still not complete. The lack of hops, the absence of a boil, and the very old-fashioned lauter tun are reasons why it’s fair to describe sahti as an archaic style of beer. It’s thought that before the art of coopering was invented, brewers used kuurna-style brewing vessels, made by hollowing out wooden logs.


In the old days, every family maintained their own yeast for the sahti, which they mostly pitched at body temperature. Today, however, everyone buys the yeast. By far the most common is a Finnish baking yeast produced by Suomen Hiiva, though some brewers prefer other baking yeasts or, in some cases, modern brewing yeast.

Suomen Hiiva cites a founding date of 1889, but the origin of its yeast strain is unknown—even the company says it doesn’t know. It is an unusual strain, however—phenolic, with strong fruity aromas that include ripe banana. Pitching temperatures range from 39°F to 86°F (4°C to 30°C). At higher temperatures, the yeast ferment powerfully and can produce ripe, pungent tropical-fruit aromas to the point where some people find it off-putting. Some brewers work around this by cooling the wort to typical lager temperatures, pitching the yeast, and then letting the fermentation rise naturally to ambient temperature.

On Steady Ground

Sahti has a strong position in that most Finns seem to know it exists, which is more than you can say for most other farmhouse ales in their home countries.

However, that doesn’t mean that sahti is universally popular. As one commercial sahti brewer said, most people say they think “it is a good idea”—meaning they approve of brewers maintaining a part of Finland’s cultural heritage—but then many add, “but I don’t like it.” Still, it remains common for people in the sahti belt to have some brewed, often by some local sahti master, for weddings and other big celebrations.
It helps that the sahti brewers have organized themselves into an association—the Suomen Sahtiseura, or Finnish Sahti Society—wholly distinct from modern homebrewers or commercial brewers. The group organizes an annual contest in which each county has a local competition that picks one champion who then participates in the national final. The judging panel is comprised of one person from each participating county. The winner gets a traditional birch-bark hat and a massive dose of prestige. Sahti brewers may reverently introduce a repeat winner as a “three-times national champion,” for example.

Since Michael Jackson’s writings made sahti relatively well known in the 1990s, many commercial breweries internationally have brewed beers that they call sahti. Most of these, with some important exceptions, have been brewed with modern processes and ingredients and, therefore, are only loosely related to real sahti.

Sahti has some legal protection as a food product under European law; its Traditional Speciality Guaranteed (TSG) appellation means that in the EU a product can only be sold as “sahti” if it’s brewed in accordance with the TSG specifications. Notably, the description of the process goes directly from straining the wort to fermenting it—there is no boiling step. Hops are optional, but modern aroma varieties would be incongruous with the traditional flavor.

If you come to Finland and want to taste real Finnish sahti, there’s no need to hire guides, translators, all-wheel-drive cars, and piles of provisions. It’s sold in various bars and shops in Helsinki. And should you venture into, say, the venerable St. Urho’s Pub next to parliament in Helsinki and ask the taciturn, impassive, middle-aged waiter for some sahti, don’t be surprised when he reaches behind the bar to haul a big, rough, 10-liter plastic canister onto the bar, and then pours you a glass from it.