Fermentation Friday - Where the wild things are

As someone whose routine for brewing typically involves two powerfully influential variables - nature and sloth - the concept of integrating native ingredients in the mind of adding an "indigenous" quality to our beers could seem a little redundant: We typically brew outside, and I'm also typically too lazy to bother minimizing the potential for something unannounced to make its appearance in the kettle. Just this minute, there's at least one beer quietly fermenting in the basement that had what, bay leaves? Plum leaves? Something seasonally shedding in the space above my brewpot falling into the midst of the boil, which was never discovered, chortling away in an anonymous fermenter. (The California bay laurel is easily denoted as indigenous, but the wild plum, maybe not so much.) Previous batches have had all manner of insect, twig, or airborne miscellany drop into the pot while I was watching - and I don't watch it all that much. "It's boiling," I say. "It's dead, poor thing. Give it an extra couple minutes to make sure it doesn't infect the batch." I never once thought those little bothers could become the topic of a blog carnival, but so it is, this month's Fermentation Friday.

What could a brewer like myself consider for a native element, that hasn't already ostensibly entered the brewing process without my conscious interference? Brian Hunt has already beaten us all to the punch by claiming the most iconic of local flora, the coastal redwood, as his personal hops substitution. I've got a number of oddities cropping up in the yard that, as Mario recently pointed out, make up a goodly percentage of the ingredient list for gruit spices, but that weedy potpourri includes so many invasive species that it hardly qualifies for indigenous status. Besides all that, what? The nanoclimate here on the orographic edge of Mt. Tamalpais is, as my good friend Alex would describe it, Ewok village. That leaves, after you've removed all the redwoods, just some ferns (sadly no fiddlehead), mushrooms, and loads of bugs. But hey, not just insects - we've got other, teensier bugs here, too.

But first, a digression...

Traditional breweries who experiment with wild yeast strains, most notably Brettanomyces, almost invariably include some statement in their marketing materials regarding how they had to utilize a completely separate fermentation facility to avoid any chance of cross-contamination in the main brewhouse. Vinnie Cilurzo, a man quite renowned locally for his dabbling with Brett makes a point to talk about the difficulties of being ostracized by various winemakers of the world-class Sonoma vintner scene, a puritanical and superstitious lot who are so afraid of that particular fungus that they won't even enter his Santa Rosa pub in fear that it'll sneak into the fibers of their clothes for a ride back to the barrelhouse like bacterial gremlins where they'll make themselves at home, all nice and funky like.

At the same time, the term "house character" conjures up such a cozy image, all fireplace glow and creaky porch swings and overstuffed down quilts, that it's favored by folks who want to inspire the taster to reconsider what on first blush might resemble a flaw, and redefine it in their mind's eye as an endearing quirk, a stamp of uniqueness, a symbol of handicraft. In brewing, "house character" is often just that, the character of the building in which the beer is brewed and aged. More so than mashing techniques or choice of malt or hops or anything else, it is often the yeast that delivers the potential to engender a brewery with a certain commonality amongst its beers, that unique stamp I mentioned above. Resident in the barrels where the beer is aged, in the air where the beer is cooled, wild yeasts typically don't have an initial dominance within the bacterial stew of a properly inoculated beer, but over time will come out and show off their true colors, to a point where small bits of Brett alone have been acknowledged for imparting beers (and wines) the impression of age.

Places where beer is truly spontaneously fermented, however, remain anomalies. The image of the Belgian brewhouse, whereupon finishing a day of boiling up a batch of beer they pump the wort up into a shallow cooling vessel on the top floor of the building, when the louvered windows open to the night air and the breeze from Brussels chills the liquor until it's ready for the fermentation tanks, bats and spiders and wild windblown beasties be damned, is not much more than a myth, with seldom exceptions. Even those beers that are cooled in open air for energy efficiency and laziness' sake (which I can totally dig) are then subject to very aggressive inoculation by highly trained house yeast strains which make quick work of the beer and leave little trace of nature's fingerprint.

But why not? Just because it's inefficient, unpredictable, potentially unsavory, and certainly unsanitary, why not throw all care to the literal wind and allow for your indigenous microflora take center stage in your next brewing adventure? The most famous yeast-inhabited zephyrs of the Senne Valley claim the local cherry trees as the sustaining force. Certainly, though, amidst all the laurels, madrones, redwoods and oaks of West Marin (not to mention the huge, locally cultivated, i.e. non-native fruit agriculture) there must be a somewhat decent cocktail of fermentation agents just waiting for the right sweet soup to take a dip in while converting it into some nice, weird beer.

So therein lies our next challenge. While it's arguable that my indolence when it comes to certain sanitizing methods has led to a sort of "house character" all its own, we've never gone truly wild. Before it gets too cold, while the persimmons and apples are still on the trees, while the walnuts are just starting to crack, the chestnuts just starting their homicidal dives off the boughs, the tomatoes and peppers beginning to wilt on the vine, and the pumpkins and squash are spreading their way across the fields in their last gasps, I think we'll cook up a nice, welcome broth of malted sweetness and leave it out for whatever guests may decide to come enjoy it. It doesn't really get more indigenous, after all, than the invisible nature that you breathe every day, that surrounds you and instinctively reminds you when you smell it again for the first time after some time away, that you're home.

Many thanks to Marcus over at FinalGravity for hosting this month's Fermentation Friday, a monthly blogging carnival gathered around the topic of homebrewing, originated by Beer Bits 2.