Dextrins & Brettanomyces

Dextrins & Brettanomyces

Cold IPA Reading Dextrins & Brettanomyces 2 minutes Next Milkshake IPA
Been a while, you’re looking well. This week we put our first long term sour in barrels, so I figured it’s time to talk Dextrins and Brettanomyces.

We wanted to produce a complex golden sour with lots of funk and a balanced acidity. I saw recently @voyager_craft_malt released an Under-modified Pilsner malt. Generally that means less enzymatic activity and more complex oligosaccharides. I figured this might be a perfect base for Brettanomyces activity.

When using brett in the primary ferment the character can become overpowering and dominate the overall complexity. So one approach to overcome this is to ferment in stainless with a brewing, saccharomyces yeast. Following primary fermentation, brett can be inoculated to finish the job. The tiny amount of residual dextrins leftover from the sacch can be metabolised by the brett, giving characteristic flavours. Brett can even convert some of the sacch metabolites, to give a more tropical funk character.

Having access to the Under-modified Pilsner malt though, I thought I could boost that brett funk a bit further without going too far. So we mashed high in temperature, used a lot of malted oats as well, and the Under-modified base malt to give a sticky, golden sour that finished at 1.018 SG. I was pleasantly surprised it finished with such a high terminal gravity, meaning there is lots of residual complex sugars for the brett to get hold of.

We also pre-soured the wort with lactobacillus, and added pediococcus and five different brett strains to the barrels. But that’s a BGW for another day.

The little one is bubbling away nicely after 72 hours of incubation, and what’s coming out of the air lock is already smelling amazing.

So hold your breath, it should be ready this time 2023.

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