Why raise mash temp?

Dogwood

Dogwood

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Why raise the mash temp to 170 at the end of the mash? Wert goes into the boil kettle and gets a lot hotter than 170! It can be very difficult and time consuming raising the temp that much, not to mention that one could get the temp too hot causing unwanted flavors, ie tannins, in the beer. I have read that the reason is to stop enzymes from doing what they want to do but what difference does it make if you mash for an hour or two and drain it into the boil kettle with the enzymes still chugging along?
thanks for the info!!
 
Yup to stop enzymatic conversation.
Also you may squeeze out a couple extra points of gravity through a mash out.
I personally don't notice a difference doing mash out vs not.
 
Dogwood said:
Why raise the mash temp to 170 at the end of the mash? Wert goes into the boil kettle and gets a lot hotter than 170! It can be very difficult and time consuming raising the temp that much, not to mention that one could get the temp too hot causing unwanted flavors, ie tannins, in the beer. I have read that the reason is to stop enzymes from doing what they want to do but what difference does it make if you mash for an hour or two and drain it into the boil kettle with the enzymes still chugging along?
thanks for the info!!
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At our scale, likely not necessary. I do a mash-out because it's easy to do on my rig and because I can be a misanthrope a bit longer by doing it. I have no provable improvement from doing so, it squeezes a point or two more gravity from the malt, which is why the big guys do it.
 
Halting the enzymatic activity in the mash at a certain point is really only needed at the professional brewer level. A pro brewer needs to have consistent output from batch to batch. Plus a pro brewer might have legal issues if his beer's ABV does not match what the label on the bottle or can says it is. A home brewer would just consider that a bonus!

One advantage for the home brewer on sparging at near mash-out temps is that the hotter water rinses more sugars off the grain than warm water. However, if it is difficult to do a hot water sparge, then don't. The difference will be negligible.
 
Nosybear said:
At our scale, likely not necessary. I do a mash-out because it's easy to do on my rig and because I can be a misanthrope a bit longer by doing it. I have no provable improvement from doing so, it squeezes a point or two more gravity from the malt, which is why the big guys do it.
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Makes perfect sense, thanks for the info! Gotta wonder why that advice is givin so often? Just wondering, because you say your misanthropic mean you're trying to make the brewing process last longer?
 
The alpha enzyme is active almost to 170F The enzymes take time to denature, so they remain active for while and at that temperature they work very fast. As Ben pointed out, it will raise the gravity a bit in most cases. It's not necessary, but if you have the ability to do it, why not?
 
Nosybear said:
More politely phrased, a few more minutes of precious solitude.
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Exactly why I'm experimenting with double decoction/double batch sparge mashes right now...next time I brew I plan on doing a mash out or at least sparging with hotter water to squeeze a little more out.
 
The raise in temperature does stop enzymatic action which may or may not be useful but the other thing it seems to do is to help with releasing sugar molecules into solution for more efficient sparging. That's the likeliest mechanism for raising gravity a little. If you do BIAB or no-sparge any potential improvement is negated.
Like @Nosybear, I do it because my system makes it easy. And I do pretty big batches using as close to pro-brewer procedures as I can. I make really good wort so I'm not inclined to cut corners by not doing it. :)
 
I think the thing I am not understanding is, why aren't all the starches converted during an hour long mash? And, if they aren't converted, how much longer should the mash go to get it done? Just trying to get a better understanding of the magic the whole process is! I have a sabco brewmajic half barrel system and do continuous recirculating during mash and a fermenter large enough to do 15 gal batches so there's a lot of water flowing through the grains. In order to do a 15 gal batch, it takes two boils. While the first boil is going on, I do raise the temp a bit while recirculating for the second boil and after draining the mash tun, there is no sweetness in the grain, that I can tell anyway. Thanks to you all for the help understanding!!
 
Dogwood said:
I think the thing I am not understanding is, why aren't all the starches converted during an hour long mash? And, if they aren't converted, how much longer should the mash go to get it done? Just trying to get a better understanding of the magic the whole process is! I have a sabco brewmajic half barrel system and do continuous recirculating during mash and a fermenter large enough to do 15 gal batches so there's a lot of water flowing through the grains. In order to do a 15 gal batch, it takes two boils. While the first boil is going on, I do raise the temp a bit while recirculating for the second boil and after draining the mash tun, there is no sweetness in the grain, that I can tell anyway. Thanks to you all for the help understanding!!
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Now someone can feel free to jump in here and correct me if I'm wrong. As long as you have a good crush, the starch should be as converted as it's going to get(with most modified malts) after 60 minutes in the 145-152 oF range. The biggest benifit, as far as I know, to sparging at higher temps is a decreased viscosity of the sugars and more efficient lautering of the grains.
 
isn't that why some people use the iodine test?
 
Dogwood said:
I think the thing I am not understanding is, why aren't all the starches converted during an hour long mash? And, if they aren't converted, how much longer should the mash go to get it done? Just trying to get a better understanding of the magic the whole process is! I have a sabco brewmajic half barrel system and do continuous recirculating during mash and a fermenter large enough to do 15 gal batches so there's a lot of water flowing through the grains. In order to do a 15 gal batch, it takes two boils. While the first boil is going on, I do raise the temp a bit while recirculating for the second boil and after draining the mash tun, there is no sweetness in the grain, that I can tell anyway. Thanks to you all for the help understanding!!
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Past the 60 minute march, the rate of conversion drops to a point where you're just not getting enough extra sugars to make it worth it to most brewers. There are some brewers who do shorter mashes for the same reason. I usually do a 75 - 90 minute (or longer) mash because I usually don't start heating my sparge water soon enough or I have errands to run. Doesn't matter to me because there is no downside to a longer mash.
 
I assume you mean why raise Sparge temp? I did some armature experimentation and found that at least for me the only reason to rinse at 170F would be to get your wort to a boil faster. You don't want to rinse grain over 170 or you get tannins and astringency, however, I tried using room temperature water to sparge and saw no difference in gravity or final product taste...it just took longer to get the final wort to a boil. I can see wanting to lock in your profile if you are a pro brewer selling a product but for home brewing my tests are that it really isn't needed. Many people who use BIAB don't sparge at all if they get good efficiency. I still do it because I like to top up before the boil and I still heat the water to 170 to speed up the brew day a little bit.
 
Enzymes are affected by temperature. The closer they get to their de-nature temperature, the faster they work. Beta amylase enzyme denatures @149-150F. Alpha amylase denatures @165F or so.

In the real world, it would be best to have those two flipped around, because alpha needs to work before beta can finish the job. Alpha splits the starch molecule down the center and creates lots of "ends". Beta can only work on the "ends" of the molecule, that's why the the alpha needs to go first. So how long does it take to convert depends on temperature. The lower temperatures and pH favors the beta enzyme, but the alpha is also working, but at a slower rate. When you get above 150F, the beta enzymes work the fastest, but are quickly denatured. Alpha continues to work up 168-170F. At those temperatures the alpha enzyme works the fastest, but like beta is quickly denatured.

Beta creates the most fermentable wort, so lower temperature keeps the beta from going away. Beta converts the starches into mostly maltose, sucrose and glucose. Alpha works at the lower temperatures, but again, at a slower rate. Alpha converts starches into dextrin, but it can also produce fermentable sugars like maltose.

Mashes can convert fairly quickly, but the problem lies with the enzymes could still be working on creating simpler sugars or more fermentable wort. So stopping the mash short reduces conversion efficiency and fermentability.

145F mash takes more time 60-90 minutes depending on the beer style.
152F works much faster, but the beta enzyme doesn't last very long, thus less fermentable wort.
158F the mash converts very quickly, but contains more dextrin because the beta didn't have much of a chance to work.
168F is super fast, but alpha is soon disable or denatured.

So why do a mashout? To get the most out of the mash as you can and to a lesser extent, denature amylase enzymes. Mashouts are not necessary. But like I said before, if you can, why not?

Sorry to be so long winded.
 
Bulin's Milker Bucket Brews said:
Now someone can feel free to jump in here and correct me if I'm wrong. As long as you have a good crush, the starch should be as converted as it's going to get(with most modified malts) after 60 minutes in the 145-152 oF range. The biggest benifit, as far as I know, to sparging at higher temps is a decreased viscosity of the sugars and more efficient lautering of the grains.
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Modern malts, as long as you haven't purposely selected an undermodified malt, can fully convert in as little as 15 minutes. Hot water dissolves sugar easier than cool, so really the only physical or chemical reason I can think of to do a mash-out is as mentioned, to free up a bit of sugar in the sparge. It won't hurt to do one and if I'm in a hurry it's one of the first things to be cut from my brew day.
 
Nosybear said:
Modern malts, as long as you haven't purposely selected an undermodified malt, can fully convert in as little as 15 minutes.
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I know that I use "modern malts" and I know that I'm still getting a substantial amount of conversion after 15 or 30 or even 45 minutes. When I check the gravity of my recirculating wort after 20 or 30 minutes of mashing at 148, it's typically reading 1.050 or so (uncorrected) on my refractometer. I'll give it a stir and let it continue. Checking at 45 minutes, it's typically 1.060 or better. I usually give it another stir and let it go another 15 minutes before raising the temp. Checking after adding water, raising the temp to 158 and letting it run for at least 15 minutes, it's usually in the 1.070+ range. From there, of course, it's diluted by a mash-out invusion and the sparge liquor and gets to the typical 1.045-ish pre-boil gravity.
This has been consistent over dozens and dozens of brews and I can't imagine stopping after just 20 or 30 minutes and expecting that I'm getting all the sugars available in the malt. :)
 
used to do it, I dont now. dont notice any difference. the time between when you would mashout and boil is soo short in a homebrew environment that it makes little difference
 
Nosybear said:
Modern malts, as long as you haven't purposely selected an undermodified malt, can fully convert in as little as 15 minutes. Hot water dissolves sugar easier than cool, so really the only physical or chemical reason I can think of to do a mash-out is as mentioned, to free up a bit of sugar in the sparge. It won't hurt to do one and if I'm in a hurry it's one of the first things to be cut from my brew day.
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I think malt modification is misunderstood. A highly modified malt has been allowed to germinate long enough for the proteins enzymes and betaglucanase to degraded to proteins and glucan to the point so a protein rest or even a glucan rest is not needed. If you have a under modified malt, there still is some proteins and beta glucan that needs to be broken down. This will help with flow in the mash and beer clarity

Highly modified malt does not covert faster than a low modified malt, it just means that mash rests to complete what the maltster failed to complete are not necessary.
 
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