If a recipe calls for a mash temperature of 156F in an infusion mash, but one were to use a step mash method whereby the temperature was slowly raised over the course of two hours from approximately 120F to 164F, would one still attain the same results? The majority of the mash temperature was at 150F with the last 30 minutes or so slowly raised to 164F. I’m guessing you wouldn’t have the same results as the lower temps early on would convert a lot of the starches to highly fermentable sugars leaving near no dextrinous sugars… my limited understanding of the conversion process. Any enlightened responses would be appreciated.
I think there will be subtle differences in the overall flavor profile noticeably in the malt flavor and mouthfeel. There may also be a more fermentable wort. As you transitioned through the mash cyle from the beta to alpha amylase active periods, the starch chains are reduced in defferent ways with the beta amylase working on the shorter branches from 130-150F whereas the alpha amylase reduces the larger trunk ends of the starch chains from 152-162 converting them into the sugars sytematically as the mash progresses through the temp cycle.
The best way to see the real difference between the two mash methods is to try the same recipe only changing the mash method and then doing a blind tasting.
Bluesman,
Thanks for the response. This beer was our second attempt at an IPA for the local 8.5 bbl brewery here in South Korea. We did manage to get our needed 40L Crystal malt - 12% of the grain bill - this time vice the black malt they substituted for crystal last time. The other 88% was actually (I just found out Saturday) Weyermann Pilsner malt. We’re trying to tune in the beer as best we can given there’s no small batch test concept here other than my homebrewed attempt at the Sierra Nevada Celebration Ale clone that was actually close (I thought). I was just wondering how the brewers using the step-mash method vice infusion mashing was going to affect the beer. And my thinking is akin to yours… that it’s not going to have the same mouth feel or subtle sweetness of the SN Celebration Ale. It’s a learning experience over here. At least they got the grain and hops right this time… and in the right order. And we’ve got 5-lbs of Cascade leaf hops to dry-hop this time vice 3-lbs. A few more attempts and we might get it right!!!
I did a bunch of Hockhurz mashes a while back and just a 10-15 minute difference at the ‘beta rest’ (I was typ at ~147* F) made a noticable difference in fermentability. This is just shootin’ from the hip but I would guess that if the mash schedule called to start at 156* F then any appreciable amount of time under ~149*F would noticably affect fermentability.
And just for the record, people do step mashes using infusions all the time (so it’s not an ‘either/or’ thing). ‘Infusion’ is just a method to adjust the mash temp and ‘step-mash’ just means that there was more than one rest temperature, they are not mutually exclusive.
I’m not sure why any brewer would go to the trouble of incorporating a protein rest with nearly any beer style. So, the prospect of starting at around 120F and waiting for the mash temp to reach the 150’s is not something I would do.
I have typically used single temp mashes, but after listening to some of the commercial brewer interviews on Brewing Network, I have begun using a short beta rest in the upper 140’s and then a quick ramp to a alpha rest temp. My first brew with that mashing approach is in the fermenter now, so I don’t have a feel for the effect yet. I fully expect that the fermentability will be higher.
Usually a single infusion at 156F means you are aiming for a beer with more body and a sweeter finish, since this temp favors the alpha amylase which makes starch into big chunks that aren’t all fermentable. By doing your step mash protocol you’ll get a more fermentable wort resulting in a drier beer with a slightly higher ABV. Since you have 12% crystal in the recipe I think you’ll still have plenty of sweetness.
Martin, I’ve begun doing some short protein rests to try and get my beers a little more clear, especially those made with TF Maris Otter. I also played with step mashes this weekend, my first attempt was poor and resulted in 64% efficiency, the second went better and I got my usual 75%.
You may want to consider other approaches, too. British malts are usually the first cited as not needing a p rest and possibly being harmed by it.
I did the step mash tests I usually do in lager season once again this winter. Back to back batches of pils, identical ingredients except one was mashed at 150 for 90 and the other got 146 for 30 and 158 for 30. I really don’t think I could tell a difference, but I’ll continue to test the theory occasionally (same with decoctions) to see if I’m missing something that will make me change my mind.
I’ll keep an eye out for negative effects on head retention.
Yeah, let us know if there’s any affect on that or body.
Wait, some people think that a protein rest would have a negative impact on the body or head retention?
I always thought the protein rest was to break down large, insoluble proteins into albumins, which would increase body and head retention.
In the highly modified malts we use today, that process is done during malting. Doing it again in the mash can lead to over degradation of the proteins. British malts are especially well modified and (the story goes) designed for single infusion mashes.
Very interesting, was your quantification based on taste and mouthfeel or was it also based on mashing efficiency and degree of attenuation? I see that you shortened the mash time for the step test. Was that because the higher temp gelatinized the starches quicker, leading you to a faster iodine test confirmation?
Martin, it was based on flavor and mouthfeel, mainly the latter. Those are usually the criteria I’m interested in with one of these tests, since I tend to drink beer more often than measure it! ;) The main reason I changed the mash time was I thought that it might even out the variables between the mashes. The thinking was that the lower temp mash would favor beta amylase and by mashing longer at a higher temp it might make the beers more the same.
Denny…I just noticed you’re T-1 and 5000 posts. 
Congrats!
This is something that I would like to start doing. I feel the body of my beers is a little thin and one-dimensional lately. Not sure what it could be but I’m wondering if doing a small step mash might help.
I also think a 90 minute, at minimum, boil will help create some depth to the flavor of my beer. Let us know what you think of the step mashing you just did when the beer is done.
I think you should try it and decide for yourself instead of taking someone else’s word for it! I haven’t found any benefits to a step mash, but that’s not to say you won’t.
Ive been step mashing from the time I started all grain brewing and have found that you don’t need to start out at a low temp like 120 to 114 as you do trash your head retention and body of the brew. Or at least that is what I found to be the case and you don’t have to be for that long of a time at the lower temps. Depending on what I’m using like rice or corn I’ll start out at around 130 to 135 and only keep it there for about 15 to 20 minuets than kick it up to the next step. If I want a little more ABV or body I’ll adjust the heats and time schedule accordingly If your making something like a stout or porter you will most defiantly trash the head and body by starting out below 130. I’ve tried a few single infusions but just don’t like how the end product comes out. Just my taste. I also use a mash out at 168 and have found it improves my efficiency as I think it helps make the surges less viscous so they pull out of the grain bed better. On a porter for instance I will mash in at 135 just to get things started for about 15 minuets and than kick it up to 156 and hold it for full conversion than mash out at 168 for 10 minuets and than batch sparge. I end up with an ABV between 5 and 6 % and a good foamy head that slowly drops down to a nice thick lace around the glass, good body and flavor profile. With out the Mash out my efficiency drops form 82% to 76% so it defiantly helps out.
I fully intend to try it myself, as everyone know, you learn best by doing. I just don’t have the time right now to brew up a batch. Spring has sprung and so has the yard work 