Mash Temperature Experiment

Has anyone done a side by side experiment comparing just how much final gravity is effected by mashing in at 148F vs 158F (or other temps)?

I am thinking about doing a double brew day pretty soon with identical beers mashed in at two end-of-spectrum temperatures and pitching 1000ml yeast starter to each (from a 2000ml starter). All (well, all controllable) variables will be identical (amount of yeast, aeration, fermentation temp, etc) & FG results to be compared.

I'm just wondering if anyone has results that I can use to get a rough idea of what to expect?

hoptualBrew said:

Has anyone done a side by side experiment comparing just how much final gravity is effected by mashing in at 148F vs 158F (or other temps)?

I am thinking about doing a double brew day pretty soon with identical beers mashed in at two end-of-spectrum temperatures and pitching 1000ml yeast starter to each (from a 2000ml starter). All (well, all controllable) variables will be identical (amount of yeast, aeration, fermentation temp, etc) & FG results to be compared.

I'm just wondering if anyone has results that I can use to get a rough idea of what to expect?

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That's a great idea!

One thing to consider is the recipe. If you went with a fairly simple recipe, as just two-row I think the results would be more "real". What I mean is, a recipe with lots of crystal malts may not attenuate as well even at 148 degrees, while a recipe with lots of simple sugars would attenuate well even at 158 degrees. So I'd suggest something like 10 pounds of plain old US two-row and a .5 pound of crystal 40L in each 5 gallon batch, and using a medium attenuating yeast.

Excellent! I found a little article after a second search that stated the following:

"See Starch Conversion. In the Limit of attenuation experiment it was found that, at a saccharification rest temperature above the temperature for maximum fermentability, an increase of the rest temperature by 1 C leads to a limit of attenuation drop of 4%" (Braukaiser, 2009).

If 1 C = 1.8 F, then for every 1.8 F over 148 F, attenuation supposedly drops 4%.

Using WY1056, attenuation of 73-77%, and comparing mash temps of 148F vs 158F should, by the information above, result in the 148F mash attenuating 22.2% more than the 158F mash. Does that sound about right?

I've never seen such an experiment, but I would be awfully interested to. Please do it and update!

Greg Doss of Wyeast just did it and reported the results at NHC in Seattle. He found that 153 produced the most fermentable wort, contrary to what we've all thought for years. He said he was going to do further experiments. Info here...http://www.homebrewersassociation.o...pdf/2012/1616-04 Attenuation - Gregg Doss.pdf

Denny said:

Greg Doss of Wyeast just did it and reported the results at NHC in Seattle. He found that 153 produced the most fermentable wort, contrary to what we've all thought for years. He said he was going to do further experiments. Info here...http://www.homebrewersassociation.o...pdf/2012/1616-04 Attenuation - Gregg Doss.pdf

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Those slides are awesome. Thanks a ton.

This is a question I have been very interested in but have not tested it myself. Is there any more information on any testing anyone has done on this? I'd love to see if someone has tried this experiment (requires two completely separate beers brewed as close to the same as possible, so it is an even bigger pain to conduct than a split batch test!) and then tasted the resulting beers to see if there really is a difference in richness or fullness, etc.

I've been wondering if a higher terminal gravity would even result in a sweeter beer, as many say longer sugars aren't really sweet. I emailed Charlie Bamforth about this several years ago, and he had an interesting idea. He thought maybe that beers with more dextrins in them seemed to be fuller and richer because naturally occurring starch enzymes on our tongues might be working on the dextrins to break them into sweeter sugars as we drink those beers. I also thought it might be fun to buy some maltodextrin and put it into some beers and see if they seem to taste richer/sweeter, etc.

If there's no real difference, then it would make sense to make the highest yielding, highest fermentable wort possible for every beer.

Denny said:

Greg Doss of Wyeast just did it and reported the results at NHC in Seattle. He found that 153 produced the most fermentable wort, contrary to what we've all thought for years. He said he was going to do further experiments. Info here...http://www.homebrewersassociation.o...pdf/2012/1616-04 Attenuation - Gregg Doss.pdf

Click to expand...

What an awesome resource! Thanks Denny!

I think I'll try mashing in at 153 for my barley wine tomorrow! I hope this data is correct!

Mmmmm. After a slight issue today, I mashed my porter at 160 instead of 153. After I finished drowning my sorrows, I realized it will be a good comparison as I have brewed this before (it's one of my regular house beers).

Expecting a high fg, and plenty of residual sugars. Could be interesting.........

Post an update!

logdrum said:

What an awesome resource! Thanks Denny!

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Knowing Greg, I have great confidence in his methods and results. That said, even he acknowledges that this is a single test and more research needs to be done.

nzbrew said:

Mmmmm. After a slight issue today, I mashed my porter at 160 instead of 153. After I finished drowning my sorrows, I realized it will be a good comparison as I have brewed this before (it's one of my regular house beers).

Expecting a high fg, and plenty of residual sugars. Could be interesting.........

Click to expand...

Fg 1022. Just tasted an initial sample, and it's definitely not a bad finished product. It was bittered with chinook, and I can taste it in the background but nowhere near as prominent as a usual batch. Slightly sweet but not overpowering. Dropped a bit of alcohol percent with the high fg.
Overall not the disaster I thought it might be.

nzbrew said:

Mmmmm. After a slight issue today, I mashed my porter at 160 instead of 153. After I finished drowning my sorrows, I realized it will be a good comparison as I have brewed this before (it's one of my regular house beers).

Expecting a high fg, and plenty of residual sugars. Could be interesting.........

Click to expand...

Fg 1022. Just tasted an initial sample, and it's definitely not a bad finished product. It was bittered with chinook, and I can taste it in the background but nowhere near as prominent as a usual batch. Slightly sweet but not overpowering. Dropped a bit of alcohol percent with the high fg.
Overall not the disaster I thought it might be.

nzbrew said:

Fg 1022. Just tasted an initial sample, and it's definitely not a bad finished product. It was bittered with chinook, and I can taste it in the background but nowhere near as prominent as a usual batch. Slightly sweet but not overpowering. Dropped a bit of alcohol percent with the high fg.
Overall not the disaster I thought it might be.

Click to expand...

what's the usual fg?

Assuming that mashing at 158F gives reduced attenuation than 148F, the big question is -- does it taste sweeter, or fuller, etc.? And since it's taste-related, (a) folks will interpret it differently, and (2) scientific results wouldn't be very helpful -- you'd have to taste it personally to truly understand. Like the word "malty" -- it's meaningless until you experience it.

P.s. I would *definitely* run experiments using real-world recipes that include crystal malts, etc. Otherwise the results probably won't translate.

SpeedYellow said:

Assuming that mashing at 158F gives reduced attenuation than 148F, the big question is -- does it taste sweeter, or fuller, etc.? And since it's taste-related, (a) folks will interpret it differently, and (2) scientific results wouldn't be very helpful -- you'd have to taste it personally to truly understand. Like the word "malty" -- it's meaningless until you experience it.

P.s. I would *definitely* run experiments using real-world recipes that include crystal malts, etc. Otherwise the results probably won't translate.

Click to expand...

From a few things I've experienced with mash temp that haven't been controlled experiments, it seems that higher mash temps don't result in sweeter beers, but more rich or full, as you say. I think it might be easier to tell the difference with a lighter beer, but maybe not. It depends on the effect size. I've rarely done side-by-side experiments, so I really have little basis for thinking anything on the topic really.

I would be interested in good, solid tests in regards to mash time affecting attenuation / fermentability of wort as well. I see a lot of anecdotal evidence and even some more solid / controlled experiments, but what I've seen so far has not confirmed that mash temp has been even and held for the duration of the mash (so in reality longer mash = more fermentable wort could really mean more that longer mash = lower mash temp = more fermentable wort).

stickyfinger said:

what's the usual fg?

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1014, so I'm 8 points high.

I'm not sure if this will make a difference. Starch doesn't gelatinize at 148F, at 158F it is jelled. At 148F, beta will be working on starch that hasn't begun to jell. At 158F, alpha will be working on jelled starch. Enzymatic action slows down when mash begins to jell. There are two different circumstances. If both were rested for the same duration of time, enzymatic action in the low temp mash will be different than what is happening in the high temp mash. The difference may become wider if mash pH is within the optimum range of a particular enzyme, at the temperature it is at during the rest. Mash thickness affects wort fermentability and attenuation....Again, I'm not sure whether any of this stuff has a bearing on the test.

Sometimes it's not a bad idea to do two temp steps in the beta range. One rest at the low temp end and another after starch gelatinizes. Or a rest at temp and pH that are in the range of proteolytic enzymes can be used. The enzyme will convert beta glucan to glucose, giving beta more to work with. Just some thoughts.

I'm personally most interested in one or two questions.

1 - Can i make a beer considerably thinner or richer tasting by varying mash temp

2 - What is the temp of maximum fermentability for a given brewing setup - ie. herms, etc

stickyfinger said:

2 - What is the temp of maximum fermentability for a given brewing setup - ie. herms, etc

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For maximum fermentability, you probably need more than just one temp. Just an educated guess here, but the Hochkurz method (146-148F followed by 160-162F) would likely maximize fermentability since those temps are selected to maximize activity of beta and alpha amylase enzymes.

How does that increase fermentability? beta works better at lower and alpha at higher. This seems like it would maximize sugar production but decrease fermentability?

I would think maximum fermentability would be a quick high temp rest followed by a drop in temp for an extended period. That's what has worked for me in the past. I'd mash in at say, 152 and then the cooler would cool off over the next couple hours of mashing/sparging.

I'm most interested in just messing with infusion mash schedules personally, that's adequate. I need to work on my mash temp stability before I can really do any good experiments with this.

If there's no real difference in taste between high and low mash temps, then it seems like it makes sense to just shoot for maximum fermentability on every single batch of beer. I would have thought someone would have tried playing with this and doing some side-by-sides by now.

I'm surprised sometimes by how dry a beer will taste and then how some low ending gravity beers seem to have a sweetness/fullness in them. Maybe it's impacted by the yeast, hopping, minerals, carbonation as much as anything, or more so.

stickyfinger said:

I'm personally most interested in one or two questions.

1 - Can i make a beer considerably thinner or richer tasting by varying mash temp

2 - What is the temp of maximum fermentability for a given brewing setup - ie. herms, etc

Click to expand...

Greg Doss of Wyeast presented a seminar at the 2012 NHC where he had found maximum fermentability at a mash temp of 153F.

"Just an educated guess here, but the Hochkurz method (146-148F followed by 160-162F) would likely maximize fermentability since those temps are selected to maximize activity of alpha then beta amylase enzymes."

Nah. You have the alpha-beta temp thing reversed. However, alpha-a is active at lower temps, only at a slower rate. Chew a chunk of bread for a few minutes. It gets sweeter. The pH of saliva varies between 6.5 and 7.5. Spit contains alpha-a. At 98.6F, spit converts starch to sugar. Just a little about spit and alpha-a.

You want high attenuating highly fermentable wort? Dough in thin. Then, step the temps 145 20 min. 149 20 minutes, 153 15 minutes, 158 10 minutes.

Using the English method, take what you get at whatever conversion temp is decided on. 153F is the cross over temp of beta and alpha. Single infusion doughed in thin at 153 might be the way to go to produce what you are going for. After the wort has fermented, figure out true attenuation. Experimenting is great. Good luck and Brew On!!

Denny said:

Greg Doss of Wyeast presented a seminar at the 2012 NHC where he had found maximum fermentability at a mash temp of 153F.

Click to expand...

Was he limiting himself to a single conversion temp? Because it would seem that some sort of stepped conversion would do better if attenuation is the goal (although I'm not sure why it would be, but hey that was the question posed).

I think they were all single-infusion mashes. I think most people just want to do a single infusion mash for simplicity, including myself. Sometimes, I want to make a beer super dry-tasting and sometimes richer tasting, perhaps a bit sweet or a perception of sweetness. I'm mostly interested in how I can impact that with mash temp, if at all. I just need to do some test batches for myself to see if my system can produce worts that are perceptibly dryer or richer/sweeter after fermentation with only mash temp/time as parameters.

stickyfinger said:

I think they were all single-infusion mashes. I think most people just want to do a single infusion mash for simplicity, including myself. Sometimes, I want to make a beer super dry-tasting and sometimes richer tasting, perhaps a bit sweet or a perception of sweetness. I'm mostly interested in how I can impact that with mash temp, if at all. I just need to do some test batches for myself to see if my system can produce worts that are perceptibly dryer or richer/sweeter after fermentation with only mash temp/time as parameters.

Click to expand...

Keep in mind that double-infusion adds very little complication, and no more time, to the process. Like you, I target dryness or more rich or whatever, depending on the beer. Which pushes me toward double-infusion (Hochkurz) on certain beers, and single-infusion on others. It's worth considering.

SpeedYellow said:

Was he limiting himself to a single conversion temp? Because it would seem that some sort of stepped conversion would do better if attenuation is the goal (although I'm not sure why it would be, but hey that was the question posed).

Click to expand...

IIRC, yeah, he was. FWIW, my own experimentation has found no difference in attenuation in a stepped mash vs. doing the whole mash at the lower step temp.

153F makes pretty good sense. You don't really get conversion going until hitting at least 65C (149F) since this is where starch gelatinizes. A temperature slightly higher than this, like 153F, would provide maximum breakdown of amylose. Temperatures lower than 65C are providing the finishing breakdown of Beta-glucan and are not contributing to starch conversion.