First time ever kettle souring, first time ever using lacto, and first time ever using the classic Dupont strain for primary fermentation. Given all of those firsts, you’d think we’d have at least eschewed at least one of those variables to make things a little “safer”. Nah, at 7bbls at a time, we can afford to let our hair down pretty much whenever we want, and so this beer was born.
After deciding that we wanted to try kettle souring for ourselves – a process by which a kettle full of wort is intentionally pitched with souring bacteria/bugs and then left for a specific period of time to sour, and then subsequently boiled thereby killing the bacteria but retaining the tartness and acidity achieved prior to the boil. The strong side of this method is that it helps to lower the risk of infecting your post boil/fermentation equipment. The possible downside is that generally speaking, the flavor profile gained from such a quick method is often not quite as complex as beers soured during traditional maturation process. It definitely matters what you want the final beer to be.
For this beer, we were after a bright, dry, highly drinkable lemon like tart blonde farmhouse style ale. We wanted a noticeable ph drop in the pre-fermented wort that would lend an acidic almost citric acid profile to a saison yeast forward beer. So, our friends at RVA Yeastlabs were contacted and a pitch of RVA600 Lactobacillus went into the kettle after chilling it down to the lacto friendly temp of ~107F and then left to sour overnight…hopefully. Sure enough, the next morning we found the ph of the wort dropped significantly and the acidity present was both noticeable and pleasant. We proceeded on with the boil as usual and for the sole hop addition, tossed in just under a 1lb/bbl of US Cascade in the whirpool to lend even more impressions of citrus. The beer was fermented with a fresh culture of RVA Yeastlabs RVA 261 Saison 1 with zero temperature control. We think we’ve made quite the summer beer at 5.5% ABV, with a soft, dry, doughy wheat derived mouthfeel, and a brite lemon like tartness that melds right into the typical Dupont yeast derived fruit like esters, and less so of the usual phenolic clove and spice character.
We’re quite pleased with our shot in the dark, and we hope you enjoy it too.