Common sense says that winemakers – and beer brewers, and bread bakers – were developing specialized Saccharomyces cerevisiae yeasts a good long while before Red Star marketed its first dried and packaged commercial product to the industry in 1965. Winemakers weren’t inoculating ferments with an aluminum foil packet they bought at the store, but that doesn’t mean they weren’t inoculating, maybe with a little bit of an already-active ferment, maybe just by having a conducive winery environment where the right kinds of yeast were happy to make a home. Either way, the yeast you’d find in any given winery or brewery weren’t the same as the yeast you’d pick up off the street, or the same as what you’d find in the next alcoholic beverage factory down the road.
Plenty of evidence, old and new, supports that story. But did those yeast become different simply because they were isolated from each other, like Darwin’s famous Galapagos finches? Or did they change because they became domesticated, because brewers and winemakers cultivated and selected them? In other words, what kind of difference did the humans make to the yeasts’ evolution?
The theory basically goes like this. If yeast populations developed in different ways just because they were physically separated, then their genomes should look like what you expect from “wild” yeast. If humans domesticated them, they should be less genetically fit, because they’ve grown accustomed to being specially cared for and protected by humans and have lost some of their capacity to live on their own.
Friday saw me thinking a lot about blending. I awoke to the seemingly impossible news that the UK (or, more precisely, English voters, as folks here in Edinburgh will be quick to point out) had voted to leave the European Union. And then I went to work, where we’re exemplifying the power of blending multidisciplinary research teams. I sat in a synthetic biology lab populated by microbiologists, geneticists, automation and biomedical engineers, computer scientists, designers, and me (the resident social scientist), by people from across Europe, Asia, and North America, where we all ended up spending more time mutually coping with Brexit than talking about yeast genetics.
Arguments in favor of the power of blending evidently didn’t win over British separatists. I can’t help but wonder whether Remain would have prevailed if the British population spent more time with good sherry and good beer instead of gulping unthinkingly through volumes of the cheap stuff. Granted, that opinion has a lot to do with the evening’s events after I left the lab, the first of which was an informal sherry tasting.
Sherry conveys one lesson about blending: resilience comes from interdependence. Fino and Manzanilla – “biologically aged” styles – age under a blanket (the unsuspecting would probably say “scum”) of oxygen-dependent yeast. In contrast with ordinary table wines, sherry barrels are only filled partially, leaving plenty of oxygen-filled head space to let flor yeast develop on the exposed surface. That space, plus the hot climate, means plenty of evaporation, which means that barrel volumes are topped up with wine from younger barrels, and so on down the line – the solera system, which also helps build microbial consistency from year to year.
My February piece for Palate Press takes a look at what wine lovers can learn about (I’d say, a more balanced, maybe more functional attitude toward) terroir. Does beer have terroir? Finding a definitive answer is, I think, less important and interesting than what we can learn by thinking through the question. It also gives me an excuse to mention Beers Made by Walking, an inventive and classically Oregonian project combining hiking, foraging, and beer. And Rogue Brewing Company, possibly the most creatively place-focused brewery in the country (at least among those big enough to sell beyond their own doors). These people embody so very much of what I love about being an Oregonian.
On Palate Press: Terroir is for Weirdos, and Other Place Lessons from Beer