This is my sahti recipe adapted for typical homebrewing equipment. I have refined it based on my own taste, various brewing experiments and conversations with renowned sahti masters. Thus this is not a classic family recipe, but nevertheless it produces a good example of today’s Finnish homebrewed sahti. The recipe comes with plenty practical farmhouse brewing tips which largely apply to brewing of koduõlu, gotlandsdricke, maltøl and kaimiškas as well.
In this text I will concentrate on practical brewing issues. For a full account on sahti, including more brewing tips and recipes from renowned sahti masters, please check my book Viking Age Brew: The Craft of Brewing Sahti Farmhouse Ale.
You’ll also find plenty of additional information at BrewingNordic. For a general overview of brewing traditions, read Sahti and Related Ancient Farmhouse Ales. If you are interested in brewing historical beers, see History of Farmhouse Ales to learn how sahti relates to medieval ales or viking age ales. For practical tips on farmhouse yeast, see my Practical Guide to Kveik and Other Farmhouse Yeast. To see how a sahti master brews with a family recipe, check Brewing Sahti in Pertunmaa.
Brewing sahti is not difficult, but it requires a mindset different than modern brewing:
- Sahti is a very process driven beer, and the old techniques are the key to success. Proper ingredients alone won’t yield authentic results.
- Modern brewing equipment can be easily fitted for the old brewing processes. Wooden vats and kuurna would certainly look cool, but stainless steel won’t rule out ancient brewing techniques.
- Some modern brewing practices need to be ignored. Modernizing the process based on current brewing knowledge often leads to modern tasting and less authentic sahti. Some techniques may sound like a recipe for disaster, but trust me, I have tested these things.
- Homebrewed sahtis are extremely varied. Although I consider my sahti recipe typical, very different examples exist also.
Grains, Juniper, Hops and Baker’s Yeast
These tips will help sourcing the ingredients:
- To my mind proper sahti can be brewed without sourcing exactly the same kind of malts, yeast and juniper ingredients the Finns are using. Farmers have brewed with what they got and so can you.
- Most sahti brewers use Finnish Sahti Malt as their base malt. Viking Malt produces this proprietary barley malt blend principally from Pilsner malt and smaller amounts of specialty malts. However, any combination of Pilsner, Vienna or Munich malts will make a good sahti. My own favorite blend for sahti is ¾ of Pilsner and ¼ of Munich.
- Most sahti recipes include 5–10 % Finnish dark rye malt called kaljamallas. This unique lightly roasted malt (color unit is around 180 EBC) adds color and lends a soft taste of dark rye bread. Although it is not a caramel malt, the best widely available substitute is perhaps caramel rye malt.
- Sahti gains its juniper flavor from branches which give woodier and more needle-like taste than berries. Most sahti folks prefer delicate juniper character, and none is always better than too much. In fact, if sourcing branches is difficult, I recommend brewing without juniper. Not even all the Finns are using juniper today and the National Sahti Competition has been won with a juniper-less sahti.
- The taste of branches may vary significantly depending on number of things like species, location and tree gender. In traditional sahti regions the species Juniperus Communis of subspecies Communis. Other species may look and taste very different, but I see no problem in using them as long as the branches are edible and taste good. Bear in mind that some juniper species may be toxic.
- Berries are an acceptable substitute to branches, although the flavor difference is noticeable. 6 g of berries added to the mash is a restrained starting point for a 20 L batch.
- Traditionally juniper branches are laid as a filter on the bottom of the lauter tun, but with a modern brewing setup this can be difficult to do. Adding juniper branches to the mash is an easy shortcut for flavor. In the mash surprisingly small amount is needed: 10 g of branches for 20 liters of sahti gives noticeable yet delicate taste.
- I used to add a small amount of hops to my sahti, but then I noticed that sahti folks like my sahti better without any taste of hops. Thus I no longer use hops in sahti.
- For authentic sahti you need baker’s yeast, or a traditionally maintained house yeast culture. Brewer’s yeast would produce good ale, but that would not be sahti.
- Suomen Hiiva’s fresh compressed baker’s yeast is by far the most popular sahti yeast, but it is difficult to obtain outside of Finland. On the other hand, Finnish and Estonian farmhouse brewers have tried many European baker’s yeast brands and they generally seem to be suitable for fermenting farmhouse ales. I advise to try your local brand of baker’s yeast.
- Baker’s yeast may contain small amount of lactic bacteria, which is usually the reason for souring of sahti. Nevertheless with the methods outlined below sahti should withstand souring for several weeks as the traditional farmhouse brewing techniques have evolved to combat bacteria.
Sahti Brewing Process
These notes will clarify some of the choices I have made in the sahti recipe:
- Traditional brewers usually mash for 5–9 hours by raising the temperature slowly from hand-warm to hot. This method reflects the past of wooden mash tuns, lack of thermometers, and less ideal homemade malts. I have simplified the procedure to three steps (60–70–80°C) and to about two and half hours. This method seems to take most out of today’s commercial malts, but if you want to mash in the most traditional way include steps at 40°C and 50°C and mash for at least five hours.
- This sahti recipe makes a raw ale, that is, neither wort nor mash is boiled. I know from a personal experience that brewers who have read their brewing books would like to add a short boil for sanitation, but that really isn’t necessary. I have fermented raw ales several times with brewer’s yeast and not a single time the ale has gone sour.
- Farmhouse ales were once fermented at hand-warm temperatures, but then the house strains were adapted to such temperatures. For baker’s yeast I recommend the range 18–25°C which is fairly typical among Finnish brewers. The lower end gives maltier sahti while the higher end emphasize fruity and spicy flavors.
- Sahti should be moved promptly to cold when fermentation begins to calm down. Most brewers do this before fermentation is completely finished, and slow secondary fermentation may continue in the cold up till serving. This method protects effectively from souring and staling, but it takes some practice to master. With rustic baker’s yeast sahti may also taste better when still sweet and slightly unfermented. Thus the finishing gravities of homebrewed sahtis are often fairly high, as in the sahti recipe below.
- You may also ferment to finish, but still transfer the ale to cold without a delay. As soon as yeast drops out, lactic bacteria may have its chance.
- Sahti is not carbonated intentionally, but it may have some fizz from the secondary fermentation.
To avoid sourness, staling and gushing ale, bear in mind these tips:
- Because sahti can still ferment in the cold storage, it is usually stored in containers which allow checking and releasing pressure. Farmhouse brewers typically use plastic canisters and PET bottles. Swing-top glass bottles can be used, if pressure build-up can be prevented with certainty. Sahti can be kegged and pushed out with carbon dioxide, but for authentic low carbonation avoid storing sahti under pressure.
- To avoid souring sahti should kept cold at all times until serving. Sahti stores best at 32–54°F (0–12°C) – the colder the better. Above 59°F (15°C) the ale can go sour even in a half day.
- Even if sahti does not sour, it loses its freshness sooner than modern ales. Drink fresh. Plan your brew with a peak moment in mind and consume within few weeks.
Sahti Recipe for 20 Liters
Original gravity: 1.097 (23°P)
Final gravity: 1.034 (8.5°P)
Alcohol by volume: 8–8.5 %
7 kg Pilsner malt
2.4 kg Munich malt
0.6 kg Kaljamallas or Caramel rye malt
10 g of juniper branches
25 g fresh compressed baker’s yeast or 10 g dry baker’s yeast
Mash grains at 60°C for 45 minutes using 2.3 liters of water per kilogram of grain. Mix juniper branches into the mash. Raise temperature to 70°C for 45 minutes, and then to 80–85°C for 15 minutes. Begin lautering, and recirculate until wort runs clear. Sparge with 80–90°C water until 20 litres of wort is collected. If using immersion chiller, insert it in the beginning of lautering into hot wort to sanitize the chiller.
Chill the wort to fermentation temperature. Dissolve fresh compressed yeast into a small amount of cold water, or rehydrate dry yeast in 40°C water. Pour the whole wort into fermenter – since wort is not boiled there is no trub. Add yeast and ferment at 18–25°C until fermentation begins to calm down. Depending on the yeast and temperature, this takes 1–3 days. When sahti still tastes sweetish, but not cloying, move fermenter to cold. If unsure, check if the gravity is in the range 1.034–1.038.
Cold condition sahti for 7–10 days and then rack into containers. Store cool at all times and release the pressure occasionally if necessary. The ale is ready in 10–14 days from the brewing – as soon as bulk of the yeast has settled.