Yeast Wranglin’

I came across the Bootleg Biology page around two years ago and was immediately taken by the idea of wrangling up some wild yeast and bacteria from my own backyard. Never once did it occur to me that I could capture local yeast regardless of the fact that I had been into sour beers for almost a decade at that point. The Senne valley is home to the microflora that gives birth to Lambic and my backyard has never existed within its boundaries. As such, I stuck to building up commercial dregs from my favorite Belgian Gueuze producers in order to brew my own sour ales. Until now.

This yeast wrangling experiment was on the backburner for a long time; basically, I was waiting for the right time. I decided the time was right after seeing the incredible bloom on this year’s blueberry crop at Sand Hill Blueberry Farm in Eustis, Fl. “Bloom”, or “blush”, is widely known in the wine making world as a source of wild yeast. It is a whitish waxy coating that the fruit produces to help protect itself. This waxy coating collects lots of wild yeast and bacteria that are just begging and waiting to get at the sugary contents just inside the skin of the fruit. Take a look at the bloom on these gorgeous blueberries!

All told we picked over eight pounds of four different varieties (Jewel, Primadonna, Emerald, Windsor).

To try and wrangle some wild bugs off of these berries I mixed up a small batch of starter wort in a mason jar. I do this in a manner I call the lazy man’s starter. Add about thirty ounces of water to a water boiler and bring up to temp. Put enough DME into a mason jar to make a thirty ounce starter at a specific gravity of 1.020. Pour boiling water into your mason jar and stir it up to dissolve the DME. Optionally, you could add hops at this point. For this experiment I decided to add a small amount of Southern Cross hops. My intention here was not to entirely inhibit lacto growth but to subvert it enough to prevent too fast or too much of a ph drop which could prevent the growth of, weaken, or even kill off some of the yeast strains present on the berries. I also added salt to this starter. Anyone who makes fermented vegetables or sourdough cultures knows that having salt in your starter at a three to five percent ratio will prevent the really nasty bugs (think salmonella, botulism, etc) from taking hold and causing some serious problems.

Once the starter was thoroughly mixed I popped a lid on it and let it chill down close to room temp. At which point I added a handful of some of the “bloomiest” blueberries in the bunch straight into the jar. Shook it really well and then let it rest on the kitchen counter where I could keep an eye on it throughout the fermentation. It took off pretty quickly and smelled rather gnarly but I expected that. Vegetable ferments tend to smell gross at first but then mature to utter deliciousness. After a week or so this starter began making that same turn. It smelled of yeast and blueberries. Week two and three showed promising flocculation and sediment along with some of the blueberry color seeping into the strange brew. I’m hoping the people over at Bootleg Biology can identify what exactly I cultured up here and that I can use it to brew up something funky.

Image: Berries fresh into the wort (bubbles are from shaking/oxygenating).

Image: Starter at the end of week one had a nice krausen and a nice layer of trub at the bottom.

Image: Taken at the end of week two. Krausen still going strong, berries are leeching some color, and a nice white layer of sediment on top of the trub.

Image: At the end of week four. The color has completely changed and the clarity has improved. I think I will decant off most of this and run it through another starter in an attempt to boost the yeast.

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