Our first collaborative xBmt with House Of Pendragon Brewing is in the books! We tackled one of the most commonly requested variables, the step mash, and had over 120 people participate in the evaluation. Results are in!
First of all, excellent experiment. I love the big turnout and significance of the results. That said… 
Methinks it could be more a total mash time thing (105/90 minutes steps vs. 80/60 single, with/without mashout times included) than an actual difference between mashing processes. Or maybe a bit of both. I have this theory (or isn’t it fact?!) that enzymes work at any temperatures until they get denatured. So all that time at 113 and 131 F for the step mash beer? Yeah, the alphas and betas are chugging along nicely for a whole hour, and then later for another 30-45 minutes again at higher temps. Compare that with just 60-80 total and there likely could be a difference from the total time, not just the process. That’s my thoughts on this. More than one variable so it’s tough to nail down exactly why there’s a difference.
But, good to know that regardless of variables, the mashing process or time or both probably do make differences. Makes sense.
Great write up
Good article. I proved to myself recently that a step mash gains me nothing compared to single infusion. For me on my system for my needs, single infusion all the way.
Great article and XBMT!
I’ve completed a couple step mashes and overall the extra commitment isn’t worth it. It’s nice to see a bit of statistical evidence to back up my personal opinions on this. I’ll stick with the single infusions.
I had a very similar thought, Dave. While I wouldn’t necessarily say that the Alpha and Beta are “chugging along nicely” at the lower temps, they are certainly active. I also think modern malt is so hot with enzymes, that even if they’re crawling along they can certainly make a significant impact on wort production, just because there is so much enzyme floating around.
Step mashing is very useful and depends mainly on:
1.) The malts used and their analysis (beta-glucan levels, S/N ratios, etc…)
2.) The target beer (what is expected)
3.) The yeast used (can the yeast benefit from the products of some of the rests to contribute to the target beer)
The ferulic acid rest demonstrated here is one such animal. Though I question the use of De Koninck Belgian yeast as opposed to a weissbeir strain that may maximize the use of the ferulic acid. Then again it wasn’t a wheat beer, perhaps it should have been.
I see that the text said that a mashout was performed on the single infusion, but I don’t see what the temperature was. I find that a mashout step does improve the extraction by around one degree Brix. The lower the final mashing step temp, the higher the step in brix between the mash step gravity and mashout gravity. So, if you mash at relatively high temps, a mashout is less worthwhile. But it is easy with my RIMS, so I always perform one.
The difference in total mashing time between the exbeeriments might be a minor contributor to a difference.
Having done this many times, I agree with the people who say the differences can be attributed to longer rest times and a mashout. But I also have found so little, if any difference, that I also stick with single infusion.
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First of all, excellent experiment. I love the big turnout and significance of the results. That said…
Methinks it could be more a total mash time thing (105/90 minutes steps vs. 80/60 single, with/without mashout times included) than an actual difference between mashing processes. Or maybe a bit of both. I have this theory (or isn’t it fact?!) that enzymes work at any temperatures until they get denatured. So all that time at 113 and 131 F for the step mash beer? Yeah, the alphas and betas are chugging along nicely for a whole hour, and then later for another 30-45 minutes again at higher temps. Compare that with just 60-80 total and there likely could be a difference from the total time, not just the process. That’s my thoughts on this. More than one variable so it’s tough to nail down exactly why there’s a difference.
But, good to know that regardless of variables, the mashing process or time or both probably do make differences. Makes sense.
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Just a quick look at McGregor, Cereal Chem. 55(5):754-765, shows that alpha-amylase is 50% active at 35 deg C, and maximally active at about 60C, after which the enzyme is quickly denatured (i.e. even though it is maximally active its stability is crap at that temp). It’s a safe assumption something similar holds true for beta. In other words, your theory is absolutely correct.
It’s hard for me to express how incredibly similar these beers were without coming across like I’m minimizing the results.
Maybe they deserve to be minimized? Not to minimize your efforts, but, ya know? I have kind of the same quandary with the results of our FWH test, too.
Haha. I totally get where you’re coming from. I guess, as someone with a “real” science background, I prefer to let the the results speak for themselves without biasing readers… too much 
This answers my questions. I always wondered if there was a “is it worth it factor”. Maybe something to try, with a certain style…but seems not the case anymore. Never done a step mash, and now probably never will.
That’s been my motivation in the past (in particular when using pilsner malt). I don’t think I’ve ever used that malt with an infusion mash as I don’t use if very often. But perhaps in the future it’s worth a shot.
I’ve found that step mash and decoction can add complexity, but with most styles only to the tune of a point or two on a score sheet at competition. Typically not worth the effort, but for a competition whore it might make the difference between 1st place and 3rd.
I just made a German pils with 100% Weyermann Barke pils malt. Single infusion at 148F for 90 minutes. Delicious beer, crystal clear.
Excellent. So perhaps just stick with a longer infusion mash when using such malts and call it a day. I’m going to have to try this out soon (for science).
I’ve single infused lagers almost exclusively until recently when I tried step mashing again. Works perfectly fine.
Denny, how do you like this malt as compared to standard Weyermann ? I’d like to try it.