Greetings Comrades! Lellemand has bioengineered a new yeast that is causing some excitement in the brewing world. Sourvisiae is a Saccharomyces yeast that is capable of producing lactic acid. Yes, you read that correctly, a saccharomyces sour yeast strain. It's like brewing witchcraft! I got to watch the fermentation of this strain occur at Blake's Brewing. I'll admit, I was a bit skeptical at first. Lellemand promotes this new yeast as a one step sour method that will not cross contaminate your equipment. Imagine the possibilities! The yeast fermented at a steady pace, and as advertised, the ph dropped at a steady pace as well, producing a pleasant lactic acid sourness reminiscent of Lactobacillious. I was pretty excited to watch the fermentation cycle unfold. This will be revolutionary for breweries and homebrewers alike. Imagine not having to worry about infecting all your equipment. And if that wasn't good enough, Sourvisiae is a time and cost saver. No need for a 24 plus hour sour mash, or pitching Lactobacillious and cranking up the heat pre-boil until then PH drops to your desired level. This is an all in one yeast, and it ferments at normal ale temps. According to Lellemand, "Sourvisiae produces alcohol and lactic acid simultaneously in less than 5 days with no off flavors and no biogenic amines production."
With a lot of sour brews, consistency between multiple batches can be an issue. It's the nature and charm of many "wild" ales, but there is definitely something appealing about having another sour option. Especially if you can nail down a good recipe and are able to replicate that brew with a saccharomyces yeast. Consistently is the foundation of any brewer's success. The beer in question (a pale ale i believe) was brewed on a Monday, and the yeast was pitched at the end of the day. By Friday the PH had dropped to 3.0 and the beer had nearly fermented dry. By the following Monday (one week after pitching) the beer had finished fermenting with a PH of 2.8! The final result is tasty beer similar to a kettle sour or Berliner Weisse. It is good by itself, but begs for a fruit addition. Researching this yeast a little more I discovered some breweries like to blend this beer or pitch with another traditional yeast to keep the PH above 3.0. Out of curiosity, a 2 ounce sample was poured and blended with 2 ounces of stout. The result, delicious. It made me wonder what this yeast could do with a dark base. Overall this too good to be true yeast looks to be the real deal. The plan is to harvest the yeast after fermentation for future use. Unfortunately at this moment Sourvisiae only available in 500 ml commercial packs. Who wants to go in on a pack? Maybe Putin can pull some strings.