Sahti recipe by Kari Likovuori

Foreword

I have been accustomed to sahti from Häme region where many brewers use rye and juniper to produce dark sahti. This time I wanted to make a medium strength sahti at about 7.5% a.b.v that has an original gravity of something like 1.080 (20 plato); finnish bakers yeast has an apparent attenuation of about 65%.

I don't get very high yield when I'm brewing sahti so I need some 22 kg of malts to get about 50-60 liters of sahti. Ok, that means...

Ingredients

20 kg     2-row pilsner malt (90%)
2 kg      dark rye malt (10%)
50 l      mash-in water (don't use more than 1:2.5)
100 g     bakers yeast
juniper branches (if you have in hand)

100 liter kettle

Juniper is nice to have but not compulsory, it balances the thick maltyness.

Procedure

Heat the water to 65-67 degrees centigrade for mash in temperature of about 62-65 degrees, let it rest until entirely hydrolysed. Heat the mash to about 80-85 degrees for sparging, better still heat the mash until it is boiling and hold there a couple of mins.

Sparging is done with whatever equipment available; kuurna, ordinary lauter tun, loop-strainer. If you use kuurna or lauter tun put the juniper on the bottom before transfering the mash into the tun. When using loop-strainer put the juniper into the mash during the mash out.

The first wort should be some 30+ liters of O.G. 1.095-1.100. After that you should sparge with hot water (80+ degrees centigrade) and collect some 20 liters more. Last runnings will have O.G. of 1,050. During the sparging you could take liter or two aside, cool it and pitch the yeast. It's good to have quickly starting fermentation.

When you have collected enough wort you can boil it, but that's not neccessary. So, cool your wort to some 25 degrees centigrade, add the yeast starter and let the miracle happen. Be aware that bakers yeast is VERY aggressive and might flow over your fermentation tun. Also it might be wise to arrange cooling to the fermenter; during my last fermentation the temperature of the fermenter was more than 10 degrees above the ambient temperature... not good, it's good to have temperature somewhere between 20-25 degrees.

After a day or two the primary fermentation is over and the O.G. should be something like 1.030. Now transfer the sahti to another vessel to leave as much trub behind as possible. Place the vessel to cool place (below 10 C) and let mature for a week or so, during this cold storage the most of the yeast will sediment in the bottom of the vessel. Transfer the sahti to bottles or plastic cans and leave the yeast behind. Be aware that sahti will still ferment and the containers should have loose caps to let extra CO₂ escape (or you could let the CO₂ out every day or two). Sahti is like British real ale and it shouldn't have much CO₂ when consumed. Don't storage sahti in warm places (over 6-7 C) or it might turn sour or it will attenuate too much.