Austin, TX – We have a new coolship at Jester King, as we begin our fourth season of spontaneous fermentation! Our coolship is used to capture airborne yeast and bacteria as the wort cools overnight. The wort then ferments “spontaneously”, meaning that we do not pitch our mixed culture of yeast and bacteria. For us, spontaneous fermentation is the ultimate partnership with nature when it comes to making beer inextricably tied to a particular time and place.
Our new coolship holds about 950 gallons of wort and is made of copper. It has been permanently situated in one of the upstairs corners of our barrel room. Windows were installed nearby to allow cold night air to flow over the coolship and inoculate the wort with native yeast and bacteria from the land. A wood ceiling was built over the top of the coolship to aid in microbial momentum. As the wort cools, steam rises and seeps into the pores of the wood above. The steam then cools and drips back into the coolship, brining with it microorganisms living in the wood. A microbial feedback loop of sorts is created, which aids the momentum of fermentation.
As we recently mentioned, we’ll blend and package our first 100% spontaneously fermented beer this winter. After several months of refermentation in the bottle, it will be released later this year. We began inoculating wort in our coolship back in February of 2013, so again, this winter is our fourth coolship season. Our coolship season is very short in central Texas, with sufficiently cold temperatures typically only present in January and February.
As for our old coolship (pictured here), we’ll be holding onto it. We have some exciting plans for it this winter! The plans involve seeking out some interesting microflora for fermentation around the Texas Hill Country. We’ll have more on this later this winter. In the meantime, we’re excited to move forward into our fourth season with a new coolship!