Is there any reason to perform a step mash in the saccharification range?

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stoutaholic

stoutaholic

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Is there any point of performing a multi-step mash if the steps are all within the saccharification range? I can understand the desire to a do a protein rest in the 120s and 130s, but is there any advantage to doing a step mash from, say, 140 F to 158 F?

It seems like the same effect would be obtained by choosing an isothermal mash at a temperature somewhere in-between those two temps. Is that correct, or is there some synergistic effect that I am not considering?

In other words, you either want to produce a wort that is on the more dextrinous side or the more fermentable side, or is balanced between the two. If you are shooting for a more detrinous wort (i.e. with a higher proportion of unfermentable sugars), you would choose an isothermal mash towards the higher end of the range -- say 158 F. If you want a more fermentable wort, you would choose an isothermal mash towards the lower end -- say 150 F. If you wanted a balanced wort, you might use 154 F. Would there be any point then, in starting a mash at say 146 and then stepping to 158? It seems like this would just produce the same wort that you would have achieved if you had chosen to mash at somewhere around 154, for example, but your mash would be less repeatable due to the variables involved in stepping.
 
I wouldn't mess with multiple sacc rests until my second or third time on the same recipe. When you find something you really like and want to make it again just a little bit differently, yeah, OK, go ahead.
 
I use multiple sacc rests when I want to get max fermentable wort, or when the grist has low diastatic power (like lots of munich malt, adjuncts etc.) I use schedules:
62C - 30' 72C - 30'
or
62C - 30' 65C - 30' 72C - 30' for even more fermentability

in 62C b-amylaze lives longer, and it has time to do its job, on the other hand above 65C more starch is being released from the grain, and a-amylase takes care of it.

I've also heard rumours, that long 72C rest improves head stability
 
To simplify the question, is there any reason why mashing at, say,
149 F and then stepping to 156 F would accomplish anything that couldn't be accomplished by a single mash at 153 F? Now, I understand that the TIME SPENT at 153 F might be different from the total time spent at 149 F and 156 F, but that is a separate variable.

My point is that, for reproducibility, it seems like you would just choose a single mash temp in order obtain the desired effect on your mash, unless there was something SPECIAL that occurs at the higher or lower temps that cannot be achieved by a medium temp. For instance, a mash at 120 - 130 F IS special, because it is out of the gelatinization and saccharification range -- it is doing something totally different from what occurs in the 140 - 158 range (though some starch conversion does occur at the temperature as well, albeit very slowly).

If you are in the saccharification range, both beta-amylase and alpha-amylase are working. At lower temps in that range, alpha-amylase is working more slowly, but it is still working. Similarly, at higher temps, beta-amylase is working more quickly, but will do less overall "work" because it is also denatured more quickly at higher temps. Everyone knows that the net effect of a quick mash at higher temps is to prefer alpha-amylase over beta-amylase, and therefore to generate a more dextrinous, less-fermentable wort, while the net effect of a longer mash at lower temps will generate a more fermentable, less dextrinous wort. So it seems like you would just choose a single mash temp based upon what kind of balance you want between fermentable and unfermentable sugars. It doesn't SEEM that there would be any particular benefit of doing a mash that FIRST preferrred beta-amylase and LATER preferred alpha-amylase. The NET effect seems like it would be the same as if you had chosen a single rest in between the two rest steps.

The reason I am asking is that I am building a HERMS that also allows the ability to perform direct fired step mashes from a burner separate from my heat exchanger, and I am now wondering about the motivation for doing this. If I am doing a step from a protein rest to a sacch rest, I would always do that with an infusion. I am having a hard time thinking of a situation in which I will actually use the direct fired burner for the mash tun. In other words, I may just be adding functionality to my system that serves no good purpose.
 
For my lagers I do step mashes. I typically do 125F - 148 F - 158F. Times vary. This winter I did a lot of 20 min:20:20 (Recomended in the Helles style book by Dornbusch). I did one at 20:30:10 as a test (still lagering). The fermentables ratios will be different for the schedules you listed (although the OG may be the same). The step mash will be different than the 153F compromise. The longer in the upper 140's the lower the final OG will be. I like the 158 F step as I believe it will add longer dextrins to the wort that won't be chewed up and thus will add a richness to the beer. I've got my first lager on tap now and it has a fabulous head, and dare I say it, a bit too much body for a German Pils - it is about right for a Helles. I think the 20:30:10 will be great for a pils.
 
Thanks for the feedback, pjj2ba. Your mash schedule is exactly the type of thing that I had originally designed my system to accomplish. What I am wondering, though, is why the last two steps of this mash schedule would create a different beer than a single mash at some temp in-between 148 F - 158 F. If they would, then that would justify the need to directly heat the mash tun in addition to providing isothermal temperature control via a HERMS.

My specific example of 153 as a compromise between 149 and 156 was just an example. I have no idea whether 153 for 60 minutes, specifically, would produce the same wort as a step mash of 149 for 30 min and 156 for 30 minutes -- it probably would not. But my point is that, unless there is something I am missing about the way starch conversion works, there SHOULD be a SINGLE time and temperature that DOES produce a wort with the same percentage of fermentables and unfermentables as the aforementioned step mash schedule. So you can see that my other assumption is that the mix of fermentables and unfermentables is the only variable we are really trying to control within the saccharification range. That assumption might also be wrong, and could therefore provide a reason for a step mash.
 
This information from Kaiser is helpful here:

Hochkurz Double Decoction

Mash_diagram_double_decoction_enhanced.gif


This version of a double decoction mash is known as Hochkurz Mash in German brewing [Narziss, 2005]. It uses a 2 temperature saccharification rest. The first decoction is used to get from the 1st saccharification rest (maltose rest) to the 2nd saccharification rest (dextrinization rest) and the 2nd decoction is used for mash-out. The dough-in can happen with the protein rest, an intermediate rest or the maltose rest. Hochkurz refers to the fact that these mashes dough in high (hoch) and are short (kurz).

To optimize the use of the beta amylase and produce a wort with high levels of maltose, German brewers often use a 2 step saccharification scheme. With today's well modified malts the protein rest is generally sipped. The first rest, usually held at 140 - 146 *F (60 - 63 *C) gives the beta amylase time to convert the glucose chains (large dextrins) into maltose. At this temperature there is already sufficient alpha amylase activity available to provide enough glucose chain ends for the beta amylase. This is needed because the beta amylase can only clip maltose from the non reducing end of a glucose chain. Due to the lower temperature, the beta amylase will be active for a longer time as it would in a single saccharification rest held at higher temperatures. To reduce and eventually terminate the beta amylase activity and to ensure that all starch in the wort has been converted (especially the small starch granules which have a higher gelatinization temperature), a dextrinization rest is held at 158 - 162 *F (70 - 72 *C). At this temperature the beta amylase is quickly deactivated and only the alpha amylase works on the starches. The rest is held until the mash is iodine negative (no starch or long dextrines in the wort). Narziss [Narziss, 2005] and Fix [Fix, 1999] suggest, that a rest at 158 - 162 *F (70 - 72 *C) benefits head retention and body of the beer though glycoproteides that are extracted from the malt but not degraded by enzymatic activity. Because of that Narziss suggests holding this rest up to 60 min. After that rest a mash-out is performed at 167-173F (75-78 C). The temperature should not be higher as this would deactivate all the alpha amylase activity and some alpha amylase activity is still needed during lautering to convert any rouge starches, that might be liberated during sparging, on their way to the kettle.

The length as well as the temperature of the maltose rest determines the fermentability of the wort. Shorter rests and/or higher temperatures will result in a less fermentable wort as the beta amylase gets less time for maltose production.

The steps for the water infusions and decoctions necessary for this mash have already been covered with the other mash schedule examples. This mash schedule can also be done w/o the use of decoctions through hot water infusions or direct heat to the mash. The latter has become standard practice in most German breweries.
Click to expand...

I just used this schedule for a helles and an O-fest. I know several guys around here are using this schedule or a variation to great effect. You would not have to use decoctions and you would still get the same conversion effects, just without the benefits of the actual deco boil.
 
stoutaholic said:
So you can see that my other assumption is that the mix of fermentables and unfermentables is the only variable we are really trying to control within the saccharification range. That assumption might also be wrong, and could therefore provide a reason for a step mash.
Click to expand...

I often use a step mash for highly attenuated beers (Kolsch, Saison, etc.):

  1. 147F for 30 minutes
  2. 151 for 15 minutes
  3. 158 for 15 minutes

For me, that mash profile reliably yields 84% - 90% attenuation (depending on the yeast). The multiple temperature steps gain you the following:

  • Faster starch conversion without compromising attenuation.
  • Complete starch conversion (enzymes are much more efficient in the 158F range).
  • Slight bump in extract efficiency (due to complete starch conversion).

Unfortunately, mash stepping is difficult for most homebrewers due to equipment limitations. But, I highly encourage people to try it if their equipment can quickly raise the temperature of the mash.
 
Great info, Kaiser always seems to be a source of excellent data. Yeah, I forgot to mention that I wasn't talking about decoction mashes. Decoctions definitely do have special effects on the mash, but do so because they use such high temps outside the saccharification range.

Lamarguy, I would expect the first 45 minutes of your mash to obtain a full or nearly full-conversion, and to produce a very fermentable wort with few dextrins. Which is what you are shooting for. The last 15 minutes at 158 are to just make sure that conversion is complete. You have nearly attained your desired balance of fermentables at the end of 45 minutes, but you are not quite sure that all starch has been converted. You don't want to just let your mash sit at 151 for another 30 minutes to an hour, because then you might overshoot your target fermentability. So you finish up at 158, which helps denature the remaining beta-amylase while ensuring that you have converted every last starch in the mash. That makes sense.

Thanks for all the help guys.
 
I know this is an old thread, but I am still curious if the following would make sense for what I want to do.

After making quite a few beers with a single infusion mash, I am going to be a little more adventurous and try to fine tune my recipes to what I like in a beer. I want to do a step mash because I want a sweeter full bodied beer, but I want it to be slightly more fermentable than if I did just a single infusion at 159 degrees.

What I want to do is to do a Mash at 148 for 20 minutes so that the Beta's can work. Then I want to raise the temp to 159 degrees for 40 minutes for the Alpha's.

Does this make sense? Anyone know if this would sufficiently do what I am looking for?

Thanks for the help.
 
Yes you can do that.

I just did an oatmeal stout. Dough in at 145*f let sit for 15 minutes.
Raise to 156 but I missed and hit 161. Its a big burner. I stir the whole time the burner is on. While on its way to 161, all the sudden the whole mash loosened up. I checked for conversion and it was done. 3 lbs flaked oats 1 lb malted wheat 17 lbs grain. No stuck sparge and 83%.

I have done both step and infusion. The step seems to make for a little better efficiency, but Otherwise I couldn't tell them apart.

I burn my mash tun a lot....
 
I recently made a Lager with multiple temperature rests. I chose not to do an acid rest as I am using heavily modified grains (20 lbs German 2-row pale). I chose to spend 15 minutes at 146 then I increased the temperature of my mash to 156 for 50 minutes. I probably spent closer to 60-70 minutes at 156 because I was re-racking a different beer from my fermenter into kegs and I lost track of time. What are some of the risks for overshooting the time spent at these higher temperatures? Will there be more Tannins in my wort? This is my first post, and only my second year as a homebrewer so If i made some really dumb mistakes, please be kind. -Luke
 

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