Brew Plan: All-Wheat Berliner Weisse

Making a beer with only wheat in your grist isn’t supposed to be easy, but I heard someone refer to it on a podcast, and ever since then I’ve wondered how to do it. The problem, of course, is the mash tun. When you brew with grains, you have to mash them, and wheat is not like barley.

Now, when I say “mash your grains”, I don’t  actually mean mashing them up. It means, basically, soaking the crushed grains in warm water to get some nice chemical reactions, like loosening up proteins, getting enzymes to convert starches to sugars, and so on… so that you end up with malty sugar water to ferment, and then rinsing them to get all the sugars you can (within reason–that is, without extracting all kinds of nasty tannins and stuff). Usually, you soak the grains in the water, then run the sugary water out slowly so as to set a “grain bed”–in effect, you use the grains as a kind of filtration bed for the sugar water, which we call wort.

Here’s the thing: barley has a husk, and wheat doesn’t. When you mash wheat, therefore, there’s no nice volume of loose husks floating about to make the grain bed work nicely as a filtration bed. Therefore, usually brewers will use some volume of barley in the “grist” (the collection of grains and stuff) from which they extract their wort. This facilitates wort drainage through the grain bed. If you don’t include some barley, you can add the “hulls” (or husks) of other grains, like rice hulls, to the mash to help ensure that your grain bed won’t goop up and get stuck, blocking the flow of wort.

Well, in Korea, it is ironically not so easy to get rice hulls: nobody has much use for them except, I assume, pig farmers. Therefore, most people brewing wheat beers here are doing it with barley and wheat in some proportions. However, I have about 2 or 3 kilos of wheat grains, and since hearing about the possibility of all-wheat beer, I’ve been curious to hear about how one could do it.

The secret, as this video explains, is BIAB, or “Brew in a Bag”:

I figure this will be the next brew I make: something quite unlike (almost) all the beers I’ve done before: it will be very tart, and very light, and something that people can drink a lot of in one go. It’ll also be ready to drink in fairly short order!

And, happily, I already have two bags I can use for grains, as well as a nice strainer I can use to set the grains down and let them drain into my mash pot. I don’t have any noble hops on hand (and I’m leery about ordering more at this particular moment), but I figure I can use a smaller amount of some other hop, and live with the difference, since the hopping will be very, very light anyway.

I plan on souring it for a few days, the same way I did the sahti I mentioned in my next-to-last brewing post (and the sahti has fermented down to 1.004 or so, by the way–the lowest apparent attenuation I’ve seen to date!), but I’ll let it sour a little longer. I figure if I extract the wort on Wednesday, I can boil when I like, anytime from Friday evening to Monday afternoon, or set it outside in the cold and let it sit till a good time to boil it comes along!

Update (9 Dec. 2010): Well, I mashed this on the afternoon of December 8th, just as planned, and hit my target gravity on the pre-mash. This means I may need to add a little water to hit the target gravity on post-boil, but that’s alright with me.

The wort is currently souring in my sealed brewpot; it was on the kitchen floor at what works out to about 38 degrees Celcius, but I read that lacto likes it to be just slightly cooler so I’ve moved it to a cooler spot. The lacto seems to be active anyway — it’s developed that same sort of corn-like aroma that the (now nicely soured) pseudo-sahti got when it was souring. Since I have plans tomorrow evening, this beer will not be boiled until something like Friday night or Saturday morning, which means it should be pretty damned sour by the time  I get around to boiling it, cooling it, and pitching the Weihanstephan yeast I have waiting. I’m definitely going to ferment this at the higher-end range, hoping for some banana esters out of it. Sour plus bananas sounds right to me, and because I like the banana (in mild amounts) more than the clovey phenols.

Update (11 Dec 2010): Well, the pH on this beer has dropped down to approximately 3.56, and some kind of fermentation is going on, clearly. When I opened up the kettle (I’m souring the wort in my (sealed) boil kettle — I won’t do it again, though) I found that there was a whitish pellicle that had formed on the little bit of wort that had gotten on top of the tin foil. There was more pellicle on the little wort that was exposed to air, as well. Obviously, the foil is not an effective way of blocking oxygen, and it’d be better if I could sour the wort in something with little or no headspace. As it is, I have one of the stem caps from a universal carboy cap on the outgassing outlet on the lid, and when I opened it there was a noticeable release of pressure.

So while it was clear something was going on, I was worried that perhaps the pH had dropped low enough to stop the lacto from doing any more work. Not only has the pH dropped, but the wort is visibly ridden with activity–if you look at it the right way.

That is to say that, seen directly, there’s only minimal bubbling, but I happened to see a light from above reflected on the surface of the wort, and it was like a living impressionist painting or something: the bubbling and microbial activity is so great that it has a remarkable effect on light reflected on its surface.

This has me wondering, though, what’s going on. The pH has been stuck at about 3.56 since yesterday. So whatever’s going on doesn’t seem to be simply or straightforwardly souring. This has me thinking it might be better to do a slightly longer, and very hot, boil. I’m thinking 20 minutes, and with the immersion heater. I want all that other stuff — the mold, the enterobacteria, the pediococcus, all of it — dead when I move the beer to the fermentation vessel.

Then I’ll pitch my Weihanstephan yeast and stick it in the hot cupboard in my kitchen, where the yeast will be good and stressed. That’s all later today, or (more likely) tomorrow morning.

UPDATE (12 Dec 2010): Well, oops. As you can see, the All-Wheat Bavarian Weisse has become an All-Wheat Bavarian Weisse. However, I can say I learned something.

Yesterday morning, I took a gravity reading and a pH reading. The gravity was still relatively steady at 1.030-ish. The pH was down to about 3.56.

This morning, the gravity was down to 1.004 or 1.005-ish, and the pH was constant.

Which means, sure, that this is going to be an incredibly sour beer… but it also means that there was only enough sugar left to produce a fraction of a percent of alcohol. Not what I was going for, to be honest. So I’m boiling up the wort with a kilo of Light DME (Dry Malt Extract) and that will provide enough alcohol for the couple of percentage points of alcohol I’m looking for for this brew.

What I’ve learned, besides the above observation that a BIAB all-wheat beer is possible, is that lactobacillus seems to bottom out with a certain pH level. I’m not sure whether that depends on strain, or whether it depends on temperature (this wort was sitting at a relatively “constant” temperature of between 35 and 38 Celcius), or wort composition, or what. What I can say is that pH stopped changing, but souring and sugar metabolization seems to have continued… and the sugar was mostly eaten up in a single 24 hour period. (Also, during the 24-hour period, the brew was mostly closer to 35 Celcius than 38. Maybe the drop in temperature allowed the lacto to become even more active?)

It seems as if the bacteria was highly active even before it started consuming sugars en masse. The observation I made yesterday about its riotous activity (as seen in a light reflected on its surface) suggests that it was doing something, even when it wasn’t crunching the sugars away so much.

A couple more observations: if you want to sour your wort or mash, do whatever you can to eliminate headspace. Putting plastic wrap or tinfoil on the surface is no substitute for eliminating headspace. No oxygen means better lacto activity and less of anything else you might have going on in there. If you have a kegging system, you might want to put the wort in a keg with some raw grains, and then fill the headspace with CO2. That’s what I’d be trying next, if I had a kegging system.

The sourness isn’t necessarily perceptible as sourness right away, pre-boil, and perceptions will differ. To me, there was a oddness to it, but it didn’t taste acidic or sour. When I asked Miss Jiwaku to try it, though, she puckered up and said it was very sour. I think I was so focused on a certain kind of sourness, and also so distracted by the alarming gravity change, that I didn’t sense the sourness the way she did. That, or maybe I was just fuzzy, as checking the wort was the first thing I did in the morning.

I’m kicking myself for not checking it last night, but I’m reasonably sure this will end up being a fine, very sour brew. I’m not all that worried. The last brew I made with a soured wort (as opposed to a soured mash) seems to have a nice tang to it; this should be a fair bit closer to lemonade. Maybe it’ll be a tolerable substitute for the radler (beer/lemonade blend) that I once liked, but no longer care for.

Ooops, one more thing: I wonder if pre-hopping the mash water helped suppress some of the nastier microbiological activity that could have happened? I guess we’ll see: the proof, as they say, is the the pudding. Or, the beer, really. I am giving it a slightly long boil, though (30-40 min), just to be sure that the lacto (and other bugs) are all truly dead.

I’ll let it cool, and pitch my Weihanstephan yeast (Wyeast 3068) in there. I don’t know how well banana is going to go with the sourness, but I don’t want the clove to get too out of hand, so I’m going to keep the brew at an elevated temperature anyway as it ferments. I may end up doing a straight all-wheat, non-soured, with the same yeast in a week’s time.

(Though I have other brewing plans, involving some raw wheat, so I might have to just harvest the yeast and save it for January or something.)

UPDATE (18 Oct. 2011):

Ah, the mistakes we make.

Camera Roll-456

So, Berliner Weisse is supposed to be clear, not cloudy, and it’s fermented with Brett and Lacto. The Lacto, I can’t really do — can’t get a brewing culture over here, and don’t feel confident I could drink the stuff up in time if I did. But things I can do differently include throwing some Brett in early in fermentation; fermenting with a clearer yeast, like Kolsch; clearing with gelatin (or lagering for ages and ages).

That said, this was a delicious mistake. The head you see above dissipated very quickly, which is no surprise given how low the pH on this beer was. But it had a refreshing, sour-lemonade character. Sourness was the be-all and end-all of this beer, perhaps too much so, but it was unique and enjoyable. My next Berliner Weisse will be a little less sour, though, and clearer, and more Bretty, I think.

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