This is an experiment in creating “Tart”, not sour, beers. Let me explain. There are many ways of making the beer itself sour. Traditionally this came from bacteria in barrels, more recently it has been from injecting some yogurt-making methods into the brewhouse. The brewer extracts the fermentable sugars from the grain with a traditional mash, runs the sugary wort into the kettle then pauses to add lactobacillus. The kettle is kept warm to keep the bacteria active and the little critters convert a portion of the sugars into lactic acid. When the desired pH is achieved, the brewer brings the kettle to a boil, killing the bacteria and continuing with the brewing process as usual. This is commonly referred to as a kettle sour.
Well that all seems like a lot of work to get a bit of tartness into your beer. So we thought, what if we take a very tart fruit, like Passion Fruit, and just rely on the tartness already there. Well, here is one such experiment.