Sahti: One of the World’s Oldest Beer Styles

By Duncan Bryant

One of the world’s oldest, continually-brewed styles of beer is the Finnish farm-style sahti. Rich with Nordic tradition, this centuries-old style has overcome many twists and turns throughout its history to remain a prevalent yet ancient style.

The Story of Sahti

The earliest written records of sahti only date back a few hundred years to the late 18th century, but casks of the traditional Finnish style were found aboard a sunken Viking ship dated back to the 9th century. Some historians even claim ancient beer styles like sahti were the motivation behind developed agriculture in Scandinavia.

Traditionally, sahti was enjoyed during special occasions like weddings and harvest festivals, and in some cases it even took on a mystical persona. Weaker versions of sahti were used as refreshment for village workers.

Despite Finland’s lengthy beer-story, commercial breweries were not historically the norm. Many traditional Finnish communities were small villages without the population needed to support a brewery. Instead, families and villages brewed beer for themselves on the local farm with readily available ingredients. As was the case in many cultures, women were the primary brewers in Finland’s past, and it was common for a mother to pass her sahti recipe to her daughters.

Even with a few rocky patches in its history, particularly around World War II, sahti was able to avoid being a once-popular-but-now-forgotten style from beer’s early days. The Sahti Society of Finland preserves the tradition through the education and celebration of the style with an annual homebrew and commercial sahti competition and festival. Some American craft brewers are even trying their hand at the style.

Exploring the Style

As a farmhouse style with extensive history, sahti has evolved throughout time into a style with a quite a bit of variation.

Traditionally, sahti was brewed entirely with ingredients available near the farm. Generally this meant a grist made entirely of malted barley, a heap of juniper branches with berries and sometimes other available herbs and spices. The malt and sometimes the juniper berries provided the fermentables, with most of the prevalent flavor coming from the juniper. However, as a farm style, ingredients changed from one village to the next. For example, the southern Tammisaari region of Finland was known for including raspberries in its sahti.

Overtime, additional ingredients were incorporated. Rye, oats and some kilned malts were used to provide additional malt flavors and allow the color to range from light-straw to amber, though the grist typically contains 80-90 percent malted barley. Around the 14th century, hops made their way onto the Finnish beer scene. They were thought to be used not only for the flavor and aroma, but their antiseptic qualities.

It wasn’t uncommon to make two different strength sahtis with the first and second runnings of the mash. The first runnings made for a strong sahti (~1.100) intended for the male villagers, while the second runnings created a weaker sahti for the women and priests. Combining the mash and sparge runnings was (and is) also done, and typically brings the gravity around 1.070-1.080.

As with many ancient ales, fermentation was initially seen as some sort of magic. Before yeast was commercially available in Finland towards the end of the 19th century, wild yeast infection was relied on for initial fermentation. If a preferred yeast was found, the cake was saved for later use much the same way homebrewers do so today. The yeast cake would either be collected in a clean jar and stored in a cool river or well, or dried and wrapped. Today, bakers yeast is the preferred strain when fermenting sahti, though bread yeasts do vary widely from one country to the next

Some sahti examples have a slight sour quality, which historically likely came from infection, but can now be intentionally created by the brewer. Lactobacillus can be added through sour/infected wort or a starter, or it can be created by using a sourdough yeast culture.

After fermentation is just about done, the sahti was traditionally enjoyed straight from the fermenter. There may be some natural carbonation from active or secondary fermentation, but generally it is seen as an “uncarbonated” style to be enjoyed soon after fermentation is done. The final product is typically a juniper-forward ale with some malt sweetness, a hint of hop flavor and bitterness and perhaps a subtle sourness.

The Brewing Process

The brewing process for sahti has changed some over time, and today it has evolved into a combination of traditional and modern brewing techniques.

Using Juniper: Juniper is usually the star of the show in sahti, but it served as more than just an ingredient. First, a bundle of juniper branches with berries were thrown into the strike water and brought to a boil. This not only added flavor to the hot liquor, but the juniper-infused liquid was used as a sanitizer in which all the equipment was dipped.

Juniper branches, along with a layer of straw, were also traditionally placed at the bottom of a a trough-like vessel called a kuurna. The wort was sent through the kuurna as a means of filtration, but also allowed the liquid to pick up some more of the juniper branch and berry character. This can be mimicked by the modern homebrewer by layering juniper branches over your mash tun’s filter device, or creating some sort of DIY kuurna.

The berries or juice of the berries is also sometimes added for more juniper flavor and an extra dose of fermentable sugars. In fact, some suggest sahti got its name from the Swedish word “saft” which referred to the juniper berry juice beer merchants used to add to ancient beers, though this is highly disputed.

If foraging for fresh juniper berries, be sure they are of the edible species. Certain species of juniper berry can add unfavorable bitter flavors or even be poisonous.

Mash Schedule: The sahti mash traditionally consisted of multiple steps starting around 100°F and getting up as high as 170°F, which could take up to six hours. Scoops of hot water or fire-hot stones were used to raise temperatures before direct-fire vessels were available.

No-Boil: Sahti was not traditionally boiled, though sometimes heated. This was likely the culprit of the sour quality that showed up in some ancient sahti examples. Some brewers will boil today for the sake of sanitation and hops, but if you want to stick to sahti’s roots, forgo to boil!

Serving: As mentioned above, sahti was traditionally served without any step to add carbonation. It is possible there is CO2 in solution from active or secondary fermentation since sahti is typically enjoyed very soon after fermentation has neared its end. Some commercial examples today will add lower levels of carbonation.

If you want an authentic sahti experience, serve the brew in a in the traditional haarikka, a two-handled wooden cup.


Duncan Bryant is the Web Coordinator for the American Homebrewers Association.

Sources: The Oxford Companion to Beer by Garret Oliver et al; Radical Brewing by Randy Mosher; “Sahti: A Traditional Finnish Brew” by Mike Schaefer (Zymurgy Special 1994)

Homebrewers Association
Homebrewers Association