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.