March 21, 2014

For Homebrew Geeks Only

Anybody that knows me, knows that I’m a geeky science guy at heart. I can’t give quick, easy answers. When I received the following e-mail with a question about the lambic recipe included in my latest Zymurgy article, I could help but give the background behind my response. I’m posting it here in case anyone else has the same question…and because it took a long time to write.
I’m hoping to make my first lambic this weekend and I thought the faux lambic recipe didn’t look too difficult – I’m not quite ready to tackle the full on turbid mash technique yet, and the faux lambic seems like an eaiser mash routine. However, I noticed the recipe didn’t include any actual mash temps – just infusion water temperatures. Could you tell me what the actual mash rest temperatures are? I appreciate it!
And my response:

So there are basically two times that you mash (the technique described in the recipe is essentially an American Double Mash). The first one where you’re just adding a little bit of malt to the wheat berries and then the second, full batch mash.

For the first mash, the intent is to borrow some of the malt’s inherent enzymes to break down the wheat berry’s sugars. This is necessary because the wheat berries have not be been malted (i.e. germinated) to activate any of these enzymes. In case you’re not familiar with amylase enzymes here is a quick rundown. Alpha and beta amylase enzymes are created in the barley during the malting process. The job of these enzymes is to strip fermentable sugar from the malt. However, these enzymes can only do their work at specific temperatures, which is why we mash; to hold a temperature and allow them to do their work. The two enzymes do their work differently; the alpha pulling it off in large, long-chained chunks and the beta, smaller, more bite-sized portions. This is important as you’ll see below.

In the first mash, without the malt, the wheat berries could sit at mash temp all day and do nothing. In the recipe I call out for a 166F mash temperature, which sounds way high I know. However, this is crucial because at this temperature you are essentially only activating the alpha amylase enzyme, and almost none of the beta amylase enzyme. If you’re a geeky graphical guy like me, I included a chart below that shows this wonderfully. This is important because you want the sugars pulled from the wheat to be the biggest, longest-chained sugars possible.

This is because of the veracity of brettanomyces, which will slowly eat everything in its path. By making large wheat sugars, brett will still leave some scraps behind. These scraps help the beer to sustain a satisfying full mouthfeel over the years and is the difference between thin watery lambic, and the authentic stuff.

In the second mash, the goal is essentially the same, you want to to be somewhere between 159F and 166F. It’s not terribly important, but just somwhere in that alpha-heavy zone. In retrospect, I should have just put the mash temp in there, but I just wrote it the way I brewed it I guess.

So that is the long, drawn out answer. The short answer is 166F for the first mash, and 158F-166F for the second mash. I apologize if you knew most of this, but I have a hard time giving an answer without explaining the reasoning!

On a side note, I might recommend a different yeast route than the Roselare blend. For the last batch that I brewed, I instead used a starter made from Crooked Stave’s Hop Savant, and then pitched packets of wyeast pedio and lacto. The esters that Crooked Stave is getting out of their brett strains are incredible; they have a distinctly tropical fruit vibe, and I’ve been blown away by the results. I don’t think Hop Savant is still out, but I believe they use the same strain in their Batch 60 which should still be available at the taproom. Even if you go the Roselare route, I’d still buy this beer (bonus, it’s delicious) and pour the dregs in the fermenter. I would not use Surrette or Vielle, as they are fairly phenol-forward and I worry that it may result in some plastic-y flavors down the road.


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