When Sydney’s Batch Brewing Co opened their second venue, Small Batch, behind the Public House Petersham midway through 2019, the plan was to use the tiny 350 litre batches as a proving ground for experimental beers and flights of fancy. So when they were approached by international yeast maestros Fermentis to conduct a little souring experiment in mid-2021, Small Batch was the perfect environment.
Armed with a brand new kind of souring bacteria, head brewer Luigi Mensi put together a recipe designed to recreate a complex old world sour ale using an exponentially quicker and cleaner kettle souring technique. For those who aren’t insane enough to browse the Milk the Funk wiki in their spare time, I’ll try to break down what this means as simply as possible.
This new lactobacillus strain is heterofermentative. That means that while it produces the lactic acid required to bring a beer’s pH down into tart territory, it’s also produces a small amount of acetic acid, or vinegar, too. Ordinarily, brewers would rather be strapped to a bed and forced to read Untappd reviews than put vinegar anywhere near their precious creations, but for Belgian styles like lambic and Flemish sour ales, a bit of acetic acid is pivotal to producing the complex vinous character for which they’re known. Unfortunately, the yeast and bacteria cultures that create these wonderful beers typically require a long time and quite specific conditions to thrive. Kettle souring, on the other hand, can usually be knocked over in a day or so and thrown in the same stainless steel kit that all the other beers are brewed in.
That brings us neatly back to Luigi’s creation. Initially named Dark Times Sour and released at Small Batch, the beer was a modern twist on a Flanders brown ale or Oud Bruin. Using the new souring bacteria and a classic Belgian saison yeast to finish off fermentation, the beer proved popular enough to shake off the experimental tag and graduate to the big kit at Marrickville.
After spending a few extra months tinkering with the recipe, Neu Bruin has been given a new name and a full scale release. Pouring a deep chocolate brown with rapidly receding head, Neu Bruin throws out big Belgian yeast esters with notes of cola and bright stonefruit. On the palate there’s a blend of cherries, chocolate, cola and just the merest suggestion of young balsamic vinegar. Neu is not as tart or as complex as I assumed it would be, but it’s super clean and has a lot more going on than your standard kettle sour. More importantly, it’s very fun and now you can casually drop heterofermentative into a conversation the next time you’re talking to your mum about lactobacillus fermentation.
Judd Owen
Published February 25, 2022 2022-02-25 00:00:00
