Time to Debunk Guidelines on Mash Temperature Impact on Body?

[Tippsy-Turvy]

Just finished reading Mike Karnowski's Homebrew - Beyond the Basics and in it he states that we should just mash in the 148-152F range - period.

If you haven't read the book, his experiment involved brewing 2 identical batches except one was mashed at 164F and the other 146F. The final products were blind-tasted by a group of 10 professional brewers and judges and 9 out of 10 thought the low-temp mash beer had marginally MORE body!?!

Any thoughts?

 

[ScrewyBrewer]

Depending on his grain bill and water pH level, mash temperature isn't the only factor in impacting a beer's body. Using a brewing water profile with a lower 5.1 pH level will reduce the beer's body and pH levels nearer 5.5 will increase the beer's body. I haven't had a chance to read the entire book yet, but having the details of his brewing water profile and grain bill would paint a better picture of his findings.

 

[JohnSand]

I haven't read it, and I don't test my mash ph. But I notice that variations in my mash temps seem to have little effect on the finished product. There was an article in BYO that stated the temperature effects are buffered by mash thickness. While I will continue to try to mash at the temp prescribed in the recipe, I worry less if I am a few degrees off.

 

[VladOfTrub]

"Beyond the Basics and in it he states that we should just mash in the 148-152F range - period."

A statement like that one, uses one umbrella to cover everything. However, the umbrella doesn't cover every style of beer.

Did the author mention anything about mash pH or what the length of the conversion rest was? Anything about water to malt ratio?

During the experiment, two entirely different circumstances took place. The mash resting at 146F was resting near the optimum temperature of beta. The wort will be highly fermentable. The other beer was brewed, using a part of the method that is used to produce low/non alcohol beer. Mash resting at 164F is at the point where beta will denature within a few minutes and alpha will denature in about 10 minutes. Very little conversion takes place.

Basically, the tasting crew compared a beer that had alcohol in it, that may have been naturally carbed. With a low alcohol, light, dead beer, that had to be artificially carbed.

There is one thing that the experiment proves. Beer shouldn't be made using high conversion temperatures. Unless, it is being brewed as a light body, low alcohol beer, using the recipe and process that the author used.

Guinness is about 3.2 alcohol, it is near beer. The body is gained through water chemistry and the addition of different types of malt.

 

[Tippsy-Turvy]

Me too - will keep targeting the recipe mash temps irrespective. Currently, mash temp seems to be the only variable I have good control over (except weighing the grains!) so it might be a while before I can tell definitively the impact temperature alone is having on my beer.

 

[blizz81]

Mash resting at 164F is at the point where beta will denature within a few minutes and alpha will denature in about 10 minutes. Very little conversion takes place.

Basically, the tasting crew compared a beer that had alcohol in it, that may have been naturally carbed. With a low alcohol, light, dead beer, that had to be artificially carbed.

There is one thing that the experiment proves. Beer shouldn't be made using high conversion temperatures. Unless, it is being brewed as a light body, low alcohol beer, using the recipe and process that the author used.

Yeah, 164F seems almost intentionally high to try to get to this conclusion. If you want to do this experiment and attempt to draw some reasonable conclusions, as others have stated, you'd want to have (and detail) the same mash pH, and probably go with three temps - maybe something like 145, 150, 156-158. And do the experiment with different grain bills / styles.

 

[smizak]

I've proved to myself time and time again in my batches that mash temps have a huge impact on body and fermentability. An IPA mashed at 150F versus a maltier pale ale at 155F, similar grain bills and identical yeast yields very noticeable differences in mouthfeel, for my system anyway.

And Vlad is dead on. At 164F, there's very little conversion, therefore very little soluble anything in the resulting wort.

 

[ArkotRamathorn]

Yeah, 164F seems almost intentionally high to try to get to this conclusion. If you want to do this experiment and attempt to draw some reasonable conclusions, as others have stated, you'd want to have (and detail) the same mash pH, and probably go with three temps - maybe something like 145, 150, 156-158. And do the experiment with different grain bills / styles.

I think it would also have to be tested a couple hundred times with different groups of judges and have them tasting beer styles that body/mouth feel are a very important aspect of the style. Rather than having them test random beer samples and asking what they thought of the body/mouth feel. They'd have to be tasting styles and the body/mouthfeel score would have to be hidden within the statistics.

Not that I think there was an observational discrimination, but the posibility is there that since they were tasting beers and specifically looking for and judging the body/mouthfeel may have skewed the results (even if it was a tiny tiny bit).

 

[broadbill]

I've proved to myself time and time again in my batches that mash temps have a huge impact on body and fermentability. An IPA mashed at 150F versus a maltier pale ale at 155F, similar grain bills

Similar or same grain bills? If they aren't identical than you can't really draw any conclusions. Even a small amount of crystal, carapils, etc can dramatically impact body and fermentability.

 

[cernst151]

I haven't read it but does he mention how long he mashed for? A longer mash time could lead to more fermentable sugars, though at 164 it does seem like you're probably denaturing your enzymes pretty quickly.

I've never done 2 identical batches at the same time like that but I can say that I mashed my recent stout at 158 (the highest mash temp I've ever used) and it was the thickest, creamiest and sweetest beer I've ever brewed with very little sweetening malts like crystal.

 

[masonsjax]

I've been hearing a lot lately that some brands and types of modern base malts are not responsive to mash temperature variations, which could explain some of the author's results. But I agree with many of the others here that he is making a lot of assumptions based on very vague circumstances. There are many more variables than he is considering or sharing.

 

[kanzimonson]

I totally agree with this. I know a few local pro brewers who mash every beer at 149F because they're trying to maximize conversion and efficiency. They feel if they need more body they can just build it in with other malts rather than these minor temp adjustments.

 

[smizak]

Similar or same grain bills? If they aren't identical than you can't really draw any conclusions. Even a small amount of crystal, carapils, etc can dramatically impact body and fermentability.

1/4lb of C20 will not yield 4 gravity points. I will consistently get 1.010-1.011 at 150F mash and 1.014-1.015 SG at 154F. Same base malt. Again, this is my system, and I do agree that building in mouthfeel with grain bill is the best way to go. I also find yeast is huge.....

 

[Owly055]

Attenuation and Body/mouthfeel are inversely related.

More attenuation = thinner beer with less mouthfeel given the same OG & grain bill
Less attenuation = heavier richer mouthfeel given the same OG & grain bill

This isn't "rocket science". Brewing is fundamentally pretty darn simple. Compare FG between beers of similar grain bills and different mash temps and the story is pretty clear. The author is pretty much right as far as I can see....... within limits.

I've found time to be at least as important as temp. As many people know, I'm an incorrigible experimenter. It is very unfortunate that we can't observe or measure conversion in the aspect of fermentability.

What I have found in my so called "in line mashing process" where I dough in with 130 deg strike water from the tap on the stove top, and heat rapidly to about 145, then 1 deg per minute (approx) up to 155, is that I need to "splash down" to about 145 using cold water, and continue back up to 155 to achieve attenuation that matches that of a one hour conventional mash. I will have full conversion in the first pass, but I will have about 3/4 of a percent less alcohol, and a slightly heavier richer brew......which is NOT a bad thing. Replace carapils with two row and you end up at about the same place.
Heating more slowly, the attenuation is better than a single pass at 1 deg per min, but for me the "splash down" works best.

I call my former methodology of striking with water about 9 F above the desired mash temp, wrapping the kettle in insulation for an hour, lifting the bag out, squeezing and boiling "blind mashing". You don't see conversion happen, and simply put your trust in God. With my "inline mash" on the stove top, I actually SEE the conversion take place, both by the clarification of the wort, and by rapidly increasing BRIX readings. It is still "blind" in that you can't see attenuation, but experience covers that blind spot pretty well.

That said, I still "blind mash" when it fits into my schedule well. And hour mashing is NOT an hour wasted, if there is something I'm doing that works out within that hour.

A recent experiment attempting to achieve wort with very low fermentability, and high sweetness, where I mashed at 162 (striking with 170F water) was a failure in terms of sweetness, but it was worthwhile in terms of knowledge. Attenuation was far better than I had expected. The brew has lots of body, yet more alcohol than I intended. The variations are far less noticeable than one would imagine, considering radical changes in procedure.

H.W.

 

[kanzimonson]

That's just an incredible amount of work for so little effect.

Time is my most expensive brewing ingredient, so I don't waste a single bit of it. I mash every beer at 150, for about 20-25 minutes. Check conversion with iodine and it's done or almost there. I don't mash out; I just start fly sparging. It stays in conversion temps throughout my lauter.

I use the 1968 London ESB in all of my American styles, which is known for typically having low attenuation, but I am usuallly in the 78-82% range.

I'm sure mash temp has an effect on final mouthfeel and attenuation, but there are so many other ways to achieve that effect. It's the same as the filtering argument: "filtering removes hops, so add more hops."

 

[blizz81]

Amusing sidebar: Something you don't see everyday: "Time is my most expensive brewing ingredient", and then "I [...] start fly sparging"!

 

[kanzimonson]

Amusing sidebar: Something you don't see everyday: "Time is my most expensive brewing ingredient", and then "I [...] start fly sparging"!

Yep, I realize these are incongruous but I'm pretty set in my equipment. I definitely would batch sparge if I started over.

I'll say though, regardless of how long it takes you to get the wort out of the MLT you still have to heat it to boiling, so I imagine the timing isn't as different as people believe.

 

[Rev2010]

Mash temp affects fermentability and gravities, that's irrefutable. How one describes body might be a different story, but there's a difference regardless. If I mash a beer at 148 it's noticeably drier and crisper than the same one done at 156, which is sweeter and a little fuller in mouthfeel. No debunking needed IMO.


Rev.

 

[TheZymurgist]

"Beyond the Basics and in it he states that we should just mash in the 148-152F range - period."

A statement like that one, uses one umbrella to cover everything. However, the umbrella doesn't cover every style of beer.

Did the author mention anything about mash pH or what the length of the conversion rest was? Anything about water to malt ratio?

During the experiment, two entirely different circumstances took place. The mash resting at 146F was resting near the optimum temperature of beta. The wort will be highly fermentable. The other beer was brewed, using a part of the method that is used to produce low/non alcohol beer. Mash resting at 164F is at the point where beta will denature within a few minutes and alpha will denature in about 10 minutes. Very little conversion takes place.

Basically, the tasting crew compared a beer that had alcohol in it, that may have been naturally carbed. With a low alcohol, light, dead beer, that had to be artificially carbed.

There is one thing that the experiment proves. Beer shouldn't be made using high conversion temperatures. Unless, it is being brewed as a light body, low alcohol beer, using the recipe and process that the author used.

Guinness is about 3.2 alcohol, it is near beer. The body is gained through water chemistry and the addition of different types of malt.

This is dead on. That experiment is complete crap. Of course the 164º mash had "less body," it was just starchy water. My first attempt at all-grain was three batches, the same recipe, all at different mash temps: 148º, 153º, and 158º. The beers were drastically different. FG were spread pretty evenly according to mash temp, and the 158º had WAY more body than the 148º mash.

I recently did a winter saison where I wanted more residual sweetness and body. Knowing that saison yeasts are highly attenuative, I mashed at 157º. The beer went from 1.065 to 1.012. Exactly what I wanted. My spring saison, with the same OG but mashed at 150º finishes at 1.004.

Lesson to be learned: Blanket statements are ALWAYS wrong.

 

[kanzimonson]

Mash temp affects fermentability and gravities, that's irrefutable. How one describes body might be a different story, but there's a difference regardless. If I mash a beer at 148 it's noticeably drier and crisper than the same one done at 156, which is sweeter and a little fuller in mouthfeel. No debunking needed IMO.


Rev.

You saying that a beer mashed at 156 is sweeter makes this lose credibility. Just because a beer finishes at a higher gravity does not necessarily mean it is a sweeter beer. An all-starch beer would have quite a high gravity but wouldn't taste sweet, right? It wouldn't be tasty either, but I'm using this extreme example because I'm sick of people straight up declaring that there is an equivalence between the perception of sweetness and the finishing gravity of a beer.

Now if we're talking two beers produced exactly the same, and one has poor fermentation, then yes the higher gravity will be sweeter. But the sugars that we perceive as sweet in beer are the same ones that the yeast ferment out.

 

[hunter_le five]

Lesson to be learned: Blanket statements are ALWAYS wrong.

Heh.

 

[Rev2010]

but I'm using this extreme example because I'm sick of people straight up declaring that there is an equivalence between the perception of sweetness and the finishing gravity of a beer.

You can be sick of it all you want, but using extreme examples to further your argument isn't logical either. I used the word sweet. Well yeah, I do detect more sweetness. All I can tell you is if I want my Wit, or Hefe, or Amber, etc a little sweeter I up the mash temp. If I find it too sweet I lower the mash temp. This is with using *the same yeasts*. Of course with a difference yeast having a different attenuation I can get different results without having to change mash temps. I'm only stating from what I've done and experienced in person brewing over the past 4 years.


Rev.

 

[kanzimonson]

But see, people say these things in the process of brewing our own beers, but it's so hard to separate what you taste in your beer from what you want to taste. We're all guilty of it.

It's frustrating that the homebrewer generally lacks the ability to perform a pure experiment. I'd love to see somebody try to brew the exact same beer with mash temps being the only difference and taste them in a triangle test. But it's so hard to get every variable right.

Did you see the article in the current Zymurgy about the big decoction experiment? It was a clusterfuggle - OGs were all over the place, beers were terribly underpitched, they (lagers) were pitched at 61F and then lowered to 51F (terrible practice). It was classic homebrewers doing an "experiment" but really they created hundreds of variables themselves.

 

[Rev2010]

It was classic homebrewers doing an "experiment" but really they created hundreds of variables themselves.

Yes, but in the OP's post he mentioned Karnowski brewed one at 146 and one at 164. I've never done a 164 mash. He didn't do a 148 mash and a 156 mash and compare the difference. Seemed too extreme and whether or not the professional judges based their opinions truly off of the "body" of the beer I can imagine one tasted good (the 146) and one tasted bad (the 164). So that's still not a well devised experiment IMO. Either way, I'm not going to stick with that narrow mash temp range solely based on him saying so.


Rev.

 

[MJ-Brewer]

There should be mention of 2 row versus 6 row in terms of the multi step mash requirements. Generally easier to stick with 2 row. Most of my brews are for darker, maltier and sweeter beers, therefore I am mashing at closer to 158 to get more unfermentables.

 

[TasunkaWitko]

The information I have states (while acknowledging that there are some exceptions to the general rule):

...[L]et the grains steep uncovered for 60 minutes at a temperature of 144 to 152 [degrees]. Any hotter and the grains will release unfermentable sugars, which will lead to a sweet, non-alcoholic beer. Any cooler, and the grains won't release any sugars, which will give you barley-flavoured water. - Brooklyn Brew Shop's BEER MAKING BOOK, 2012, p.26

I'm not experienced enough to get into the science or chemistry involved, but the passage regarding "unfermentable sugars" resulting in a "sweet" final product that has less alcohol might be relevant.

 

[blizz81]

It's frustrating that the homebrewer generally lacks the ability to perform a pure experiment. I'd love to see somebody try to brew the exact same beer with mash temps being the only difference and taste them in a triangle test. But it's so hard to get every variable right.

Did you see the article in the current Zymurgy about the big decoction experiment? It was a clusterfuggle - OGs were all over the place, beers were terribly underpitched, they (lagers) were pitched at 61F and then lowered to 51F (terrible practice). It was classic homebrewers doing an "experiment" but really they created hundreds of variables themselves.

I've had fantasies recently of a beer-related business venture differing from the normal "I'm gonna open a brewpub" where a larger-volume brew system would be devised to conduct controlled experiments and / or training opportunities (BJCP tasting training, hop school, etc). I'm sure I'm the 43,210th person to think up such an opportunity, and am definitely not the type to chase fantasies, but it's fun to have ideas in heads sometimes.

 

[masonsjax]

I'm pretty sure Kai Troester has tested this topic thoroughly. No need to speculate, just check out his site.
http://braukaiser.com/wiki/index.ph...ciency_in_single_infusion_mashing#Temperature

 

[helibrewer]

Mouthfeel and Body are really preceptions that we apply to describe the finishing gravity for the most part. I do not know of any study that has been able to quantify or in any other way isolate what body and mouthfeel are.

Does the author present the OG/FG of the test mashes? The 146F mash barely gets to gelatinization temperature so it is going to leave unfermentable dextrins. The 164F is just not going to convert. You need to hit 148F to gelatinize the starch granules which is why the technique of a steady ramp, then cooling back works...you have to get hot enough to gelatinize, then can cool back to optimum enzyme temperature...it's just a lot of work.

Targeting 150-152 makes a lot of sense if you can make the beer you like by just altering the grain bill and yeast strain to arrive at your desired FG.

 

[VladOfTrub]

"Did you see the article in the current Zymurgy about the big decoction experiment? It was a clusterfuggle - OGs were all over the place, beers were terribly underpitched, they (lagers) were pitched at 61F and then lowered to 51F (terrible practice). It was classic homebrewers doing an "experiment" but really they created hundreds of variables themselves."

You nailed it. But, they must have been proud of their ineptness. They published it. It goes along with other info out there about the decoction method. At best, they are a rough schematic of the process. The inept brewers probably followed one of those schematics.

Quote:
...[L]et the grains steep uncovered for 60 minutes at a temperature of 144 to 152 [degrees]. Any hotter and the grains will release unfermentable sugars, which will lead to a sweet, non-alcoholic beer. Any cooler, and the grains won't release any sugars, which will give you barley-flavoured water. - Brooklyn Brew Shop's BEER MAKING BOOK, 2012, p.26

Here again, is another statement that is in the same boat as the experiment in the original post. It is a little worse than the original. The guy that wrote it not only mentions time and temperatures. He gets into what happens when the mash is outside of the temperatures. That's where he messed up pretty bad.
Have you ever chewed a chunk of bread for 10 or 15 minutes? Evidently, the author hasn't. Or, it never occurred to him that the same amylase that turns bread starch to sugar at body temperature is the same amylase that converts malt.

 

[kanzimonson]

The information I have states (while acknowledging that there are some exceptions to the general rule):

...[L]et the grains steep uncovered for 60 minutes at a temperature of 144 to 152 [degrees]. Any hotter and the grains will release unfermentable sugars, which will lead to a sweet, non-alcoholic beer. Any cooler, and the grains won't release any sugars, which will give you barley-flavoured water. - Brooklyn Brew Shop's BEER MAKING BOOK, 2012, p.26


I'm not experienced enough to get into the science or chemistry involved, but the passage regarding "unfermentable sugars" resulting in a "sweet" final product that has less alcohol might be relevant.

I can't say that the pamphlet put out by Whole Foods, designed for fairly new brewers, is the most trustworthy of sources.

I wish there were more work done on what's left after the mash. I want to know all the types of sugars, which ones are fermentable (and by which yeast strains), how the human tongue perceives each of them, etc. I stand by my statement that a higher finishing gravity does not definitively mean that a beer is sweeter.

 

[TasunkaWitko]

I really don't have a dog in this fight, and I don't have the experience to debate intelligently on it - you guys can duke it out and I accept that you know what you're talking about.

But....

pamphlet put out by Whole Foods

 

[kanzimonson]

I really don't have a dog in this fight, and I don't have the experience to debate intelligently on it - you gujys can duke it out and I accept that you know what you're talking about.

But....

My apologies - the "Brooklyn Brew Shop" IS the stuff sold in Whole Foods, but I didn't realize that it is an actual separate LHBS. Still, "How To Brew" is the bible of homebrewing, and I'm wary of things put out by homebrew shops, who have to ride that line between providing good information and helping new brewers stay interested in the hobby.

 

[JustLooking]

I stand by my statement that a higher finishing gravity does not definitively mean that a beer is sweeter.

Sweetness comes from residual sugars. Malty is the product of quality grains.

 

[Peyope]

Interesting, can't read this teas now but I'll have to come back later.

 

[kanzimonson]

Sweetness comes from residual sugars. Malty is the product of quality grains.

Let's assume we're pitching a proper amount and achieving a proper fermentation. What do you believe is left after the yeast have consumed their sugars?

 

[Callacave]

I always find that Malty and Sweet are terms that sort of cross each other at times, and depending on who is using them to describe a beer can be interpreted differently by another person.

I think the term "sweet" is a little too harsh when describing beer. When people say sweet they tend to think of something like a cake.

To me, a higher FG doesn't give me the perception of sweet as it does more for mouthfeel. I think "sweetness" can come from what type of grains you use.

I have a Porter on tap that finished at 1.032. It's not overly sweet to me, but has more of a great, full mouthfeel.

Ethanol can also taste sweet to people, so that is also a contributing factor.

At any rate, it's an interesting discussion, and it would be interesting if the experiment could've been conducted at less extreme temps.

 

[TasunkaWitko]

I'm wary of things put out by homebrew shops, who have to ride that line between providing good information and helping new brewers stay interested in the hobby.

You do make a good point, there - carry on!

 

[BeatnikTom]

"
During the experiment, two entirely different circumstances took place. The mash resting at 146F was resting near the optimum temperature of beta. The wort will be highly fermentable. The other beer was brewed, using a part of the method that is used to produce low/non alcohol beer. Mash resting at 164F is at the point where beta will denature within a few minutes and alpha will denature in about 10 minutes. Very little conversion takes place.

This is a flawed experiment for the reason stated above.

A better experiment would be to blind taste 148 vs. 154. I guarantee a difference.

The author's statement is a really off-base assertion based on a BS experiment.

 

[skw]

Sweetness comes from residual sugars. Malty is the product of quality grains.

Hm, my copy of "Yeast" says:

Higher mash temperatures do not develop more malt character or flavor, nor does it really result in much sweetness. The long-chain dextrins created at high mash temperatures are at most only very slightly sweet.