Among those interested in traditional farmhouse brewing, the writings of Mika Laitinen have had a strong following for years. If Michael Jackson’s writings brought international attention to sahti in the 1990s, Laitinen’s have added substantially more expertise and local perspective.
His Brewing Nordic website—and his book Viking Age Brew, published in 2019—put sahti in its proper context as a Northern European farmhouse ale. They also offer plenty of practical tips on how to brew it. For those who want to dig deeper into the style and the culture surrounding it, there are no better resources than those.
Here, Laitinen shares some of the key things to know if you want to brew a typical sahti in the Finnish tradition.
Water: “Typical sahti brewers don’t think about water much—they just take what they have. Finnish water is usually very soft, low in minerals. But I think sahti can be brewed with any good water.”
Malt: “Occasionally, I want to brew mostly with barley malt. And then, when I want a strong rye flavor, I brew what I call rye sahti. Then it has something like 30 percent rye, but that varies a lot depending on family traditions and what people like.
“Barley sahti is standard, typical sahti, which people know the best. It’s more instantly likeable—it’s very rich and sweet—so that’s usually what I offer first to people. When people want to learn about brewing sahti, that’s my first advice, to brew with barley [malt]. … And when I say barley sahti, it usually means there’s [still] a small amount of dark rye malt involved.
“But rye sahti is very special. It has a different kind of taste and mouthfeel, and I like to brew it occasionally because it’s so different. It’s usually a bit drier, and [for] people who don’t like really sweet beers, it’s better to offer them a rye sahti. It’s [grainier,] and usually there’s quite a clear and nice flavor of toffee. I feel that the pale rye malt gives a kind of bready, toffee flavor. … There is one commercial brewery [Olu Bryki Raum] that brews a traditional western Finnish sahti with 50 percent unmalted rye. There are also rye brewers elsewhere in Finland, but usually they use much less rye.”
Lautering with a Kuurna: “It’s not necessarily more efficient, but traditional brewers know how to use [a kuurna] in a really efficient way. Modern lauter tuns work equally well for brewing sahti—except with high amounts of rye.” (Rye is high in gummy beta glucans and can be a challenge to lauter; for more on that, see “Demystify Rye,” beerandbrewing.com.)
Hops (or Lack Thereof): “Often, when I don’t need to harvest yeast from sahti, then I don’t use hops. I feel that the flavor of hops or the bitterness is not typical for sahti, so I try to avoid any kind of hop taste in sahti. But when I harvest yeast from sahti, then I add a small amount of bitterness to fight the lactic bacteria, but it’s not going to add much taste. … I make a hop tea, and then I add it to the mash. I find it the most convenient way to use hops in sahti, but there are also many more traditional ways of using hops.
“Sometimes I’ve added slightly more hops, but traditional sahti drinkers always notice that, and they say that [I’ve] used too much hops. And even if you use some hops, it’s better to use a light flavor, like German-style.”
Juniper: “The first thing is that sahti need not have any juniper, and some people have difficulties in accepting that. It can be just malt, yeast, water that makes a really good sahti. But, of course, using juniper is very traditional in sahti. And when I say juniper, it means juniper branches, not just the berries.
“And there are many ways to use juniper. Some [brewers,] for example, put [the branches] into the kuurna during lautering, and some make a juniper infusion, and some do both. But when I want a good juniper flavor, I like to use the infusion—it’s much better and more predictable. But the infusion temperature also affects a lot of the flavor. Some people boil the infusion, and then it can give a really sharp juniper flavor, kind of pine-like, and even a solventy flavor. I usually keep it, at most, at [176°F] 80°C. Above that, and it’s going to be risky for leeching tannins and solventy flavors.”
Juniper Berries: “It’s a modern shortcut for brewing sahti, but I find that [juniper berries] work because sahti usually doesn’t have a strong juniper flavor. So, you can get a mild and good-enough flavor with berries also—a slightly different flavor, but I think it works.”
Smoke: “Traditional home malting has virtually died out, so people now brew [sahti] mostly with commercial malts. There are a few brewers who malt themselves, [but] they don’t make smoky malts anymore. So, today, people are not used to smoky flavors in sahti. Some people have tried it—and I like it—but many traditional sahti drinkers don’t want sahti to taste smoky. It’s kind of a special trick, which some people like and some don’t. If I want to serve my sahti to traditional sahti drinkers, then I’d probably skip the smoked malt. [Smoked sahti] works better with today’s beer drinkers, who like a wide variety of flavors.”
To Boil or Not to Boil the Mash: “Usually, I like my sahti as a proper raw ale, without any boiling, so I keep my maximum temperature as [176°F] 80°C. And then, when I lauter, I don’t heat the wort, so that will be the maximum temperature for the whole brew. … My feeling is that the boiled-mash version slightly reduces the amount of proteins in the final sahti. The unboiled version is more like a raw ale. Still, even a boiled-mash sahti tastes like a raw ale—but slightly less so. When I say ‘raw ale,’ I [mean] that raw ales have a strong cereal flavor, and even kind of straw-type flavors.”
But Not the Wort: “I like to stress that it’s a raw-ale tradition. Some sahti brewers and one or two commercial brewers boil the wort—but I think it’s against the tradition. Or, at least, it’s a much newer tradition.”
Yeast: “Most sahti brewers use Finnish baker’s yeast [Suomen Hiiva], which gives a strong spicy flavor—like phenolic flavors—but not diacetyl. … But any baker’s yeast should work because even in Finland some brewers like to use other baker’s yeast brands. Finland doesn’t have a factory for dried baker’s yeast, so some brewers use dried baker’s yeast from Spain or France or other places, and they always seem to work.
“I like to use Norwegian or Lithuanian farmhouse yeasts. I’ve written a blog post about why I think this is a traditional sahti yeast also because sahti brewers used to maintain their own house yeasts. The difference between baker’s yeast and farmhouse yeast is that modern baker’s yeast is a single-strain yeast, and kveik and Lithuanian farmhouse yeast are usually a combination of several strains. Also, the farmhouse yeasts are meant for brewing, but baker’s yeast isn’t. For example, baker’s yeast doesn’t flocculate very well, which is kind of a disadvantage.”
Clarity: “Usually [sahti] is hazy, but it can clear up in the cellar. For example, one month in the cellar can make a very bright sahti. And then, if it’s very bright, people can start to wonder whether it’s traditionally brewed. So, they kind of prefer at least a slightly hazy sahti.”
Carbonation: “Many sahtis don’t have any carbonation—it’s completely still. And some people like really low carbonation, but even low carbonation is not required. … In old brewing texts, they clearly say that they put sahti into wooden casks, and the first part’s very foamy when they open the cask. So, it’s not untraditional to have carbonation, especially if it comes from the residual fermentation. But today, it’s not the most common thing.”
Strength: “The most typical range is from 7 to 9 [percent ABV], and today 6 percent is considered the lower limit of sahti. And some people brew above 9 or 10, but I think it’s not so good anymore because sahti should be easy-drinking, and you should be able to drink it by pints and not by sipping from a glass. The strong alcohol can reduce drinkability, which should be important for sahti. … And then in the lower range, like 6 to 7, there’s a risk that it feels thin and lacking because there’s no carbonation.”
When to Brew, When to Drink
“With sahti, proper time of drinking is important because it’s supposed to be very fresh. … Today, most sahti brewers make the sahti two weeks before the celebration. Some like to do slightly less, and some more, but two weeks is very typical. And with kveik and Lithuanian yeast, I can do it faster—then I like seven to 10 days. I think it’s even better when I get it very fresh, into drinking condition.
“Usually [sahti] is brewed for a special party, where it is at its best. It doesn’t need to be good for months after brewing—it just has to be really good for the celebration.”