Our brewers Zach and Kevin have been harvesting wild yeast using various methods for awhile now. Finding and reusing yeast is a key component of brewing efficiency. This week they embarked on a new journey with a Koelschip. A Koelschip (sometimes spelled coolship) is an open top, wide vessel allowing a large surface area for hot wort to cool with exposure to the surrounding air.
Once filled, the Koelschip was moved to rest and cool overnight. As the wort cooled naturally, the microbes in the air inoculated the wort. The next day, Zach and Kevin put the cooled wart in a barrel where they hope to see signs of fermentation soon – and will let it do its thing for about a year. Beer science!