As we work to open our second location, we wanted to try a test of making spontaneously fermented beer at our nano. This method involves using only ambient yeast and bacteria in the surrounding air to inoculate and ferment the beer. For this first trial run, we are brewing three one barrel batches of the same beer. They will be blended together to fill one white wine barrel once that barrel is emptied in a few months, and aged for an extended period until a sufficiently good beer results, if it even does.
For this procedure, we wanted to test a couple of ideas that I had. First, the grain bill and mash is somewhat unique. Forgoing a turbid mash, the labor-intensive traditional technique used by Belgian lambic brewers, we ran a simple two step mash of a saccharification rest at 162 degrees, followed by a big decoction to hit a 172 mash-out, and a 190 degree sparge. This should accomplish somewhat similar results of a turbid mash.
The idea behind a turbid mash and/or this mash schedule is to create a wort that is high in long-chain sugars. The reason for this is that aggressive wild Saccharomyces strains may ferment your beer too quickly and leave very little for brett and pedio to work with, so you want to create a less fermentable wort. Our grain bill also involves creating even more complex starches in the wort. Usually, a high amount of unmalted wheat is used. However, I am a fan of using rye over wheat to achieve this. Rye contributes considerably more dextrins than wheat.
The last part of the grain bill is just purely something unique and fun. We used Red X malt for most of the base. Red X is a 13 L kilned malt that is kind of like a “super Vienna” malt in terms of flavor. It is very, very malty. I’ve used it before and always wanted to try to use it in a sour to balance sharp acidity and provide a deeper flavor. I think it could work quite well for this, but regardless, it provides a beautiful ruby color.
80% Best Malz Red X
20% rye malt
We skipped a boil and sent our 180 degree wort straight to the kettle where it was left overnight to cool and capture microbes outside the brewery garden. We added a small amount of Saaz hops (0.5 ounces for 26 gallons) to the wort. Aged hops left at room temperature for an extended period are traditionally used. Unfortunately, we didn’t have any on hand. However, using a small amount of low alpha hops at 180 degrees may achieve similar results.
Another unorthodox method we tried was spiking the surrounding flora with brett from previous beers. Our elderberry and cherry trees were periodically splashed with yeast, where it could grow and hopefully mutate over time.
Obviously, our 30 gallon kettle we use for pilots is not a coolship. However, the cooling rate should be somewhat similar to a large commercial coolship, and this is just a test for when we begin brewing 3 BBL batches of these beers at the nano with our future coolship.
The resulting beers will be allowed to ferment in steel for 3 months, before being tasted and blended in a barrel to age. If any or all of them taste completely horrendous due to enteric bacteria or clostridium, they will be tossed. Furthermore, we’ll plate and examine the beer in the lab to see which microbes are present. If all goes well, after extended aging (8 months to two years) the beer will be refermented with raspberries in the barrel, and bottled.
If this works, we’ll begin more production next spring. Fingers crossed!