I have a process related question that I would like the community’s buy-in on. It’s not so much the decoction process itself, but more the idea of a low-temp (104°F/40°C) dough-in step for mashes that involve a decoction.
In trying to take my german lagers to the next step, I’ve recently been employing a decoction to move from beta to alpha rests. One of the things I read (I believe from a traditional German brewing source/approach; can’t remember where right now) is that it is beneficial to do a ~104°F/40°C dough-in step at around 1qt/lb before moving to the beta rest (around 1.8qt/lb, via infusion). I believe the rationale is that this helps get the enzymes into solution better before moving to the beta and subsequently pulling grain out for the decoction. It makes sense (to me), but I can also be talked into a lot with only a little amount of seemingly scientific merit.
Despite not being around the typical protein rest temp, it seems like low temp dough-in step generates that thick protein gunk that makes lautering a pain, so I’d like to get rid of it - but only if it doesn’t serve a good purpose towards the decoction process. I use a picnic cooler MLT and boiling water to go from 104°F to beta, so eliminating this step would be nice. Using boiling water infusion to hit beta also somewhat short-changes me in the batch sparging department.
The low temperature dough in was at one time common, but by the middle of the 20th century was regarded by German brewers as obsolete and in fact detrimental in most beers (sources in DeClerck; occasional exception Dunkel with poorly modified malt, practically an oxymoron for Dunkles malt.) It served as a beta glucan rest, eliminating gums that hinder lautering and, later, filtration of the finished beer. This is unnecessary with modern (meaning, essentially, post WW2) malts with their favorable beta glucan levels, as is a protein rest that you cannot avoid passing through if you dough in at these temperatures. It also encourages oxygen exposure at the most sensitive temperatures (below 140°F.) I have in the past used mash programs including this rest, and have found no benefits. You may feel you are doing honor to tradition, but with the materials available today the result will be beer with compromised flavor, body and foam, and stability. As for the issue of hydration of the malt and getting enzymes into solution, crush malt properly, mix well at dough in, and in 5 minutes you’re there.
Right. I’m fairly savvy on the concept of protein rests and as such avoid that altogether. Just to reiterate, though: i’m not concerned with the protein rest concept as it relates to this, as i’m not doing it for that. At 104°F, i believe that’s lower than the intended target for a protein rest. I understood this rest to be beneficial to get enzymes fully into solution before decocting. Also, I’m not intending on doing anything remotely LODO. Thanks for the assurance on the hydration aspect.
Trouble is, you can’t help but pass through protein territory on the way up from 104°F, and the highly enzymatic malts we have don’t need much time to act within their temperature range – so you will in effect be doing a protein rest. In the old triple decoction, it was necessary to hydrate the mash before pulling the first decoction. But this was as I say an obsolete process long ago. If you want to use a decoction to move from beta to alpha or to mash off, you’ll already have a fully functioning mash going at beta, etc., temperature. The decoction is just another way of boosting the temperature, like an infusion; it doesn’t require any other special conditions. So you can just mash in for your first rest at 146°F or wherever, and be fine.
Since switching to an all-electric system, I now do step mashes with HERMS, but used to do decoction often.
Like many other things, there are a variety of decoction methods and/or schedules. Kai Troester has some great and helpful info on decoction methods and science on his wiki site:
He has a nice 3-part video of the process, too - scroll to the bottom of the wiki page for those.
Warning: It’s easy to go “down the rabbit hole” on Kai’s site. He posted all kinds of interesting experiment- and science-based information for brewers. Kai hasn’t been on any of the forums or updated the wiki site in a long time, but it’s still really good info. Anybody know what Kai is up to these days?
Low temp dough ins are good for doing an acid rest (useful if you practice Rheinheitsgeboit and have alkaline water, but understanding water chemistry is better) and a beta-glucan rest for under-modified malts. Since under-modified malts basically don’t exist anymore why do a beta-glucan rest?
The low temp water for low temp dough in contains more oxygen than the water at saccharification temps. Also you have to stir the bed a lot to get the malts properly wetted. The more oxygen the more gunk. So avoid low-temp dough ins!
I suppose you could effectively bypass the protein rest that way. But I think you’ll still be well advised to skip the low dough in. Just use decoction as a fun twist on a Hochkurz.
Thanks for the info. Yup - i reference his stuff a lot. I’ve got a decent handle on decoction - theory and execution, but the one (somewhat recent) german lager reference i came across mentioned this 104°F step and I haven’t been able to find reference to the practice anywhere else… hence this thread.
Not sure if you might be referring to the link name or not. If so, the articles are Brauwelt articles simply hosted on the Low Oxygen site. They don’t necessarily pertain to LODO techniques.
Nope; I saw the info in the links were general decoction, thanks. I was more touching on the comment Kramerog stated about oxygen and I wanted to nip that in the bud, so to speak, before this spun off into a LODO arguement.
Randy Mosher in Radical Brewing in the section on decoction says: “Don’t skip the 95F dough in if you are doing a mash with a large proportion of Munich or other lightly roasted malt. These malts have had some of the enzymes deactivated due to the heat used in kilning, although they still will convert themselves. Beta glucanase is the enzyme most sensitive to to destruction by heat. It operates at a very low temperature, below 100F. If you start your mash out at 122F or higher, you run the risk of not letting the small amount of glucanase enzymes left do their job of degrading beta glucans. When these gummy materials are present they turn your mash into the proverbial bowl full of jelly.” (P. 110)
This (the idea that Munich malt requires a glucanase rest) may or may not have been true at one time, but it is not now. Munich malts are fully modified and retain their full package of enzymes like paler malts. Moreover, as has been mentioned above, glucanase rests are unnecessary with any fully modified, modern malt, and if they were, the same temperature would apply for any malt, Munich or otherwise. What he says doesn’t really make sense; it would never work in any mash doughed in at 122°F or above.
A problem we come up against in trying to be true to tradition is that old practices were designed to suit the needs of the materials of the time. We may think we’ll get authentic results from following those practices, but they will give unsatisfactory results with modern materials. Randy Mosher has summarized the old methods as detailed in old sources (possibly including Thausing, who I had in mind,) but you just can’t get the sort of malt that was used then. Really we’re lucky we don’t have to go to all the trouble. I speak from some experience with trying old mash programs. And honestly in the realm of brewing literature, 2004 is pretty outdated. ;) (But there is a lot of other good stuff in that book…)
Stefan Zehendner, brewer of the highly esteemed Mönchsambacher Lagerbier, is talking about that modern, more-modified type of malt, processed and ready for infusion like tea.
Gelöst, incidentally, can mean deleted or erased. It also means dissolved, which is technically what happens to the internal grain structure as it’s modified during malting. “The malt is crisp or brittle,” he says. “The new kinds of malt are very thin. So they must make infusion with the new malts, and I think decoction is better.” Zehendner is suggesting that modern malts lack something. Do they make good beer? Of course. But cook them in a decoction mash—a process that adds qualities that specialty malts can only simulate—and they fold like a house of cards.
They lose the body and foam stability associated with a proper decoction mash and relatively less-modified malts.
Zehendner, for his lagers, uses 100 percent Pilsner malt from the Bamberger Mälzerei—the neighbor to Weyermann, less known internationally but perhaps more favored among local brewers. It is well-suited to decoction, and any doubters might want to ponder it over a glass of Mönchsambacher—deep burnished gold, with a fresh-sweet-malt center that can stand up to its ample bitterness, topped with typically lush white foam that stays through the end of the glass, leaving stripes of lace all the way down to mark each gulp you’ve taken.
