Time for an update on the wild side of the brewery, folks!
As many of you are undoubtedly aware, we have a love of sour beers here at Rivertown. They are a true labor of love, requiring a lot of patience and faith that organisms outside of your control are going to give you something delicious of their own accord. We’ve been making them since we started and the people have let us know that they like the direction we’ve been taking with them.
On that note, one of the most common questions we hear in the taproom is “Are you doing anything new and exciting with the sours”. It can be a tricky thing to put a new one out, if for no other reason than the amount of time you have to devote to them. We have barrels aging beer anywhere from six months to three years. This kind of time frame makes it really hard to experiment, since you risk creating a beer that “just won’t fly” months down the road. But, that might not be the case anymore!
Over the past nine months or so, we’ve been running a number of experiments. Each one was aimed at learning how all the crazy organisms that produce these sour ales work. We tracking everything from speed, optimal environment, interaction, all the way to just when do they flat out stop. If you’ve been in for one of my Saturday tours, you may have heard about them. Initially we were just trying to figure out if we could capture viable wild yeast from the air in the brewery (the answer was yes, twice). During that experiment we saw enough variation in my sample batches, and some significant differences in speed compared to our barrels, that it seemed like the next logical step would be to see if we could increase the effects we were seeing by forcing specific aging conditions. That’s what the last six months have been like and now we are at the point where it’s time to share this project with all of you.
Without going into too much detail, we found that we achieved faster and much more pronounced results by introducing different strains of organisms at different times—instead of all at once, like we do in the barrels. During this process, different strains will start and stop being active over the course of the year, as the environment changes which strain is favored. We discovered that, an abundance of sugar combined with controlling which strains are present, has allowed me to produce something tasty, yet completely different, in a shorter time period.
So to test this out, we present Tom’s latest contraption: the Solera Beerealis.
This is a modification to a traditional solera set up, which relies on always drawing out and filling from the bottom of the vessel, while never completely emptying it. This allows you to keep a very healthy and active culture going because you never break the pellicle on the surface. Essentially, what we are doing is tying three strains together. The pickiest strain is at the top, where it gets fresh unfermented wort to chew on. Being the only organism present, it can go to town in an ideal environment, producing the desired flavors in no more than a week or two. After that, we can move half the batch down to the second chamber, through the hose that you see attached, for a nice, funky, sour fermentation. The large amount of sugars still present allow for very aggressive flavor profiles, achieved in only a few weeks. Finally, the third chamber is for drying out the beer and making sure it’s ready to serve. This chamber will be dosed with a wild strain captured inside the brewery. It will combine with small amounts of the previous two strains to finish developing the complexity of the beer, allowing us to produce small amounts of sour beer in a much shorter time frame. Perfect for experimental batches.
We hope you all enjoyed reading this. While we love making the great beers you see out and about, we firmly believe that one of the most important things for us, as brewers, is not to forget that sense of adventure and experimentation that got us where we are in the first place. And there’s no greater way to celebrate this brewing spirit than to share our adventures with all of you!
This post has not been revised since publication.