Michael Tonsmeire likes getting wild.
He specialises in brewing ‘tart and acidic’ beers using wild fermentations, barrel-aging, blending, and microbes like Lactobacillus. His 2014 book American Sour Beers is a how-to manual for adapting traditional sour-brewing techniques for modern home- and craft-brewers. While Michael has kept his day job as an economist, he’s also a Flavor Developer for Modern Times, and he blogs about his brewing experiences and recipes at The Mad Fermentationist.
Michael will be in New Zealand next month as a headline speaker at the New Zealand Home-brewers' Conference.
Beertown.NZ: Sour beers have been the big trend in NZ brewing (home and craft) for the past couple of years. Why do you think the styles have suddenly become so popular, all over the (New) world?
Michael Tonsmeire: Coincidentally my book, American Sour Beers, came out in 2014. I think it was more good timing than anything, but the openness of brewers with their process has helped other breweries have confidence and succeed at producing sours. Brewers are always looking for a challenge, and fermenting with microbes other than brewer's yeast and aging in oak barrels is just that.
From a consumer perspective, sourness opens up an entirely different part of the palate than "clean" beers, which run along the single axis of sweet to bitter. Acidity brings refreshment, and can create some uniquely food-friendly beers (cutting through richness). Add to that the enhancement to fruit beers (often flat without extra acidity) and the strange and fascinating flavors brought by Brettanomyces. They create beers that can appeal to wine drinkers, and connoisseurs who obsess over the differences between each batch. They also feed into the slow food and farm-to-table movements.
B: New World craft brewers have taken traditional European styles and reinvented them (e.g., IPA). Is the same thing happening with sours?
MT: It is – for example, New World gose and Berliner weisse are often more acidic than the few remaining German examples. There is also less sweetness in sour reds and browns than those from Flanders. Although, because of the less precise nature of sour beer creation compared to clean beers, I don't necessarily see whole new styles being created as rapidly. In America anyway there has been just a general push outside of those surviving European sour styles. Part of that is brewers filling a few barrels with wort from an existing beer (saison, mild, quad etc.). I love to see the dry hopped sours, unique blends, and surprising fruit and vegetable additions.
B: The term ‘sour’ covers a range of styles and brewing techniques – do we need to be more specific to recognise the variety of beers and flavours now being produced?
MT: I've never especially cared for the word sour as it can be off-putting. Tart or acidic are a bit more appealing. There are funky beers, wild ales, and mixed-fermentations. There isn't a perfect umbrella term, and that's OK. While it can make ordering challenging, it requires breweries and bars to use language to convey what can be expected. I'm glad to see more breweries using numbers as well (pH or titratable acidity) to express how much sourness their beers contain. There is no single number that captures the character of the acidity (it's the same with IBUs for hop bitterness), but it is a nice start.
B: When and how did you begin to develop an interest in brewing in general and sours in particular?
MT: When I started learning about craft beer in college I drank sour beers only occasionally because of their rarity and price. Soon after college, I had a couple months off before starting a new job 500 miles away so I started four batches of beer with microbes other than brewer's yeast. I was worried about contaminating my clean beers with these yeast and bacteria, so I left them to age at my parents' house. From there I was hooked.
One of the best things about brewing these beers at home is that you get to taste the flavors as they develop. I've held onto bottles for as long as ten years and still thoroughly enjoyed the results! Now that I have a basement it is filled with barrels, fermentors, aging hops, and bottles...lots of bottles.
B: And what inspired you to write American Sour Beers in 2014?
MT: From blogging I started writing magazine articles. I contacted a few brewers for quotes for an article about sour beers for Brew Your Own magazine. I asked them a few questions for personal curiosity and got wonderfully detailed and passionate responses. I started writing my best practices for brewing sour beer.
I originally planned to self-publish, but after hitting 100,000 words I decided to reach out to Brewers Publications. It turned out that they'd been looking for someone to write a book like that for a couple years. They'd been turned down because practices were changing and knowledge was growing quickly. They were happy to have my manuscript, and maybe I'll get to update it in a few years once there is nothing else to learn about these weird relics of the time before Pasteur... ha!