Wednesday, July 8, 2015

Buckwheat Sour Saison - Recipe, Brewing with Unmalted Adjuncts, & Cereal Mashing Techniques

Let's explore our memory banks for a moment. Even as hombrewers, making beer can get pretty stressful when lots of things start to go wrong. What's the worst brew-day you've ever had?

If I thought about it really hard, I could probably come up with a couple epically annoying brew days in my short career as a brewer. But the one that stands out foremost is the day I brewed this buckwheat sour saison and tried to package an imperial stout at the same time. I can remember it distinctly, because: that day sucked. Hey! Why don't I tell you about it?

I've been fascinated by buckwheat for a while, especially after trying eye-opening beers like Hill Farmstead Le Sarrasin, and reading some intriguing things about the chemical precursors it may set up for microbes to transform. I love stuff like this, the sympathetic magic of fermentation, able to take one simple input and really surprise you with its output. No one seems to completely understand how all of this alchemy works just yet, which makes it even more intriguing to those of us, like me, obsessed with obscurities and unknown horizons.

It's also really nice when things turn out in spite of bothersome complications. But that's like, half of all homebrewing.

For this brew, a 5 gallon batch that I made last fall, I picked up 3 lbs of buckwheat groats from a local health food store. It was probably not wise to brew this on Halloween, inviting some kind of curse down upon me, but whatever, I went for it. With so much unmalted buckwheat in the grain bill, I knew that I wanted to try a cereal mash. At 21%, it seemed like too much to use without trying to extract the sugars. Plus, I was simply curious to try out a cereal mash; I'd never used the technique before, but I knew the modifications we were getting on our brewing system at Kent Falls would make such elaborate mashing procedures at least somewhat easier for future brews. (We have rakes in our kettle that allow us to mash into the kettle, step mash or cereal mash, and transfer into the lauter tun).

Most homebrewers have little reason to ever cereal mash. The large majority of ingredients we use simply don't require it. When unmalted, many raw grains will not release their starches in our typical single infusion-style mashes. But on either the homebrew or the commercial scale, a cereal mash is a ton of effort, and most grains can be obtained in a malted form, or thrown into the recipe in smaller percentages without using a cereal mash simply to steal their flavor qualities, without much concern for their fermentables. If you do want to obtain those fermentables, you need to process the grain in a way that will unlock them. Within a certain temperature range, a cereal mash will gelatanize the starches in the kernel / seed / whatever, by destroying the structure, and thus allowing mash enzymes to later access these starches. It's sort of the "nuke the site from orbit... it's the only way to be sure" of mashing techniques. The exact range of gelatinization varies from plant to plant, but a spread between 120 F to 140 F (50-60 C) will hit it for most grains used in home brewing. Like so:

  • Unmalted Barley: 140-150 F (60-65C)
  • Wheat: 136-147 F (58-64 C)
  • Rye: 135-158 F (57-70 C)
  • Oats: 127-138 F (53-59 C)
  • Corn (Maize): 143-165 F (62-74 C)
  • Rice: 154-172 F (68-78 C)

  • I haven't been able to find this info for buckwheat, just this generalized summary from a research paper: "The gelatinization temperature of buckwheat flour is higher than that of wheat flour, its gelatinization resistance is greater, the water absorption of its starch granules is stronger, the viscosity is higher and increases quickly during cooling." Looking back at the bullet-chart above, one can surmise (okay, guess) that the gelitinization range of buckwheat is probably similar to that of rice.

    For most of those grains listed above, much easier for the homebrewer is simply buying flaked or torrified versions. Commonly available through homebrew supply shops, these two options also gelatinize the grain by breaking down its cellular structure through heat and pressure. Buying grains processed like this is a whole lot easier than cereal mashing, and if you have that option, there aren't too many situations in which there's reason not to take it.

    Buckwheat, being fairly obscure, is not easy to obtain malted, especially not at the homebrew scale. Unsurprisingly, flaked buckwheat and torrified buckwheat are not common features on homebrew shop shelves either, or even easy to obtain for commercial breweries (though there is one source). Speaking of obscure, here are some fun facts about buckwheat: it's not a grass or related to grain at all, and is actually related to rhubarb, except the seeds are the part consumed (rhubarb is a vegetable where the stalks are eaten — not a fruit, as you might think by its frequent placement in pies).

    Procedurally, a cereal mash goes like this:

    1). Mill the cereal adjuncts down to a fine grist, and supplement with about 15% of the overall total malted barley base malt. The malted barley will help to add the enzymes necessary for conversion, which many cereal adjuncts lack. 2). Add hot water at 3 quarts per pound. You want a thin mash here, because you'll be edging it through a boil later, and don't want an overly-gummy soup that'll scorch (as I would later find out). First, though, you're targeting a simple infusion-style mash, so 3). bring the temperature to within the gelitinization range and hold that for 20 minutes to allow the gelitinization to occur. 4). After the geli stage, you can raise your cereal mash up to a gentle boil. Here's where I ran into trouble: the mash will go from a soup of loose grains to a thick, porridge-like gruel. But my understanding of the procedure on brew-day was different: I had thought I was meant to hold the temperature of the boil for an additional 20 minutes. So upon reaching a gentle simmer, thinking this light boiling was that which would ultimately destroy the starches, complete gelatinization, and achieve great success, 5). I kept stirring feverishly. This was actually unnecessary — 6). upon hitting the boil, apparently I could have added the cereal mash right into my main mash — but I stood there and diligently blended the congealing porridge goo with a wooden mixing spoon for another 20 minutes, 7). like some kind of asshole.

    Long story short: my cereal mash got a little bit scorched. Just a little though.

    Coming out of a cereal mash — especially one that got cooked for longer than necessary, a mildly-toasted extra-thick porridge — buckwheat muck is super mucky. Added to my standard mash of pilsner malt, it got really extra muckity muck. And I got a stuck sparge. A stuck sparge like I've never seen before. I think this was a stuck sparge so stuck it actually went back in time to find my run-off and kill its parents, thus altering the time-space continuum so that my run-off never existed at all. 

    I stirred in some rice hulls. The buckwheat muck went back in time again and killed the parents of rice hulls. Rice hulls no longer exist. When I write the words "rice hulls," you have no idea what those symbols on your screen are even meant to represent, because the concept of rice hulls no longer exists in our world. For a moment, or a minute, I just stood there fuming and perplexed. I momentarily considered just dumping the batch, thinking I would never manage to extract any liquid out of the quagmire.

    Long story actually-not-that-short, I had to shovel my entire mash tun over into another vessel, add another like a truckload of rice hulls (what? rice huh?) to the bottom of the tun all over the screen until it had an impenetrable security blanket. I then scooped the mash back on top. From there, things finally actually went smoothly. With this beer. Also on that day, I was trying to keg an imperial stout. Have I mentioned how much I hate leaf hops and their tendency to clog things? Anyway, that's a story for another time.

    I fermented this guy in my 6 gallon homebrew barrel that's home to one of my house cultures, which, upon taking residence in the barrel, has definitely grown more and more sour over time. Something else that I mean to write about another time: how mixed cultures can change in their performance after repeated repitchings. This was about the third use of this particular house culture, and the lactobacillus in the barrel clearly were ready to leap out ahead and get to work — over the four months I let this age, it's developed a nice strong acidity, but firmly in the lactic side of things. No acetic, and nothing harsh, fortunately. In fact, the very subtle smoke character imparted by scorching my mash a bit didn't hurt the beer at all, to my great surprise. You can taste it in the background, but it tastes just like a very subtle smokiness, to the point where I enjoy it as an incredible complexity, rather than a flaw. That, in addition to whatever nuances the buckwheat added (it grows harder and harder to determine what came from where), make this taste like a much older sour than it really is; I find it to be excitingly complex for a beer so young. It's far more multi-layered than other young sour saisons I've had.

    Coincidentally, yesterday I brewed a buckwheat saison on the commercial scale. It'll be going into a 10 bbl stainless tank and getting a new construction of my mixed house cultures. Needless to say, I didn't try to emulate exactly the same mashing procedure — but writing about this new batch is an entry for another time.

    6.0 Gal., All Grain
    Brewed: 10.30.14
    Bottled On: 1.17.15
    Fermented at room temp, 72 F
    OG: 1.065
    FG: 1.004
    ABV: 8%

    77.5% [#11] Pilsner malt
    21.1% [#3] buckwheat
    1.4% [3.2 oz] acid malt (pH adjustment)

    Hop Schedule-
    1 oz Brewer's Gold @flameout

    White Labs Saison II
    House Sour Saison Culture - White Mana


    1. One of the breweries I tried in Portland was using buck wheat cause it's gluten-free. Didn't realize it's a vegetable, not a grain. Good read as always.

    2. Just wanted to mention that there's other papers that mention the gelatinization temperature of Buckwheat. Turns out it's 67C.

    3. Could have sworn I commented on this, but, must not have. Have you ever brewed a clean buckwheat saison, or is it really about the biotransformation via brett?


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