While there is some evidence of the historical usage of not boiling, it has become a topic of more interest lately. Anecdotally, it appears to have a distinct texture and flavour associated with it.
The major caveat with producing raw beer is DMS. The precursor to DMS is SMM (an amino acid) that is found in malt. SMM converts to DMS at about 76oC. So by raising the beer to pasteurisation temperatures you will get DMS conversion. DMS is normally produced during wort production but is driven off with about 15 minutes of boiling. Importantly for raw beer, DMS is so volatile that it can also be driven off through CO2 egress, which occurs through a vigorous ferment. You can also use better modified malts that don’t have as much SMM in them. Modern pale malts have a very low SMM level.
This week we launched not one, but two raw beer variants. First is a no boil Berliner Weisse, which can be found at Saccharomyces Beer Café. It has even paired with some killer syrups from The Village Pickle. Second is a no boil Berliner Weisse with Strawberry and Mango fruits, which is launching at The Scratch this Saturday night at The Weekend of Tartness.
When producing the Berliner we used lots of Wheat and Pils malt to achieve a light colour. It was absolutely loaded with DMS at the start of ferment; in dark moments I even considered dumping it all on Luke’s lawn. But with a slightly more rapid ferment at 22-24oC the DMS disappeared over the ferment, to reveal a moorish and delicate saline Berliner Weisse.
Raw beer, it’s coming.