Really Long Mash

[stuchambers]

Hey guys,

I hope this doesn't rub to many people the wrong way but.
Can I do a very long mash say 24hrs at room temperature?
I do understand that mashing at lower temp say 64 will result in more simple sugars and therefor more alcohol while using a higher temp 68 will give more maltose and a sweeter wort.
What do you think the result of this extended room temperature mash would be?

Cheers Stu

 

[RobB]

The enzymes which convert your starch to sugar are active between approximately 60 and 70 degrees. At room temperature they would do nothing and after 24 hours you'll have exactly what you started with - soggy grain.

 

[Acasta]

In short: Nothing.

In long: have a quick read of this chapter of john palmers "how to brew" it will explain the things you need to know about temp and the conversion of starch to sugar.
http://www.howtobrew.com/section3/chapter14.html

Theres alot of technical info in there, don't be overwhelmed. Just read it and take in what you can. It will undoubtedly help you.

 

[stuchambers]

I will defiantly do some reading but from what I understand amylase is present in your saliva and that works at approx 38 degrees.
So Im sorry I wont be convinced that nothing happens at all. I am however very happy to be corrected.

Adding more wood to this fire if I used non malted barley and then added commercially available enzymes would you achieve the same result as using a malted barley.

Cheers Stu

 

[Acasta]

The enzymes are what convert the starch into sugar;

The temperature most often quoted for mashing is about 153F. This is a compromise between the two temperatures that the two enzymes favor. Alpha works best at 154-162F, while beta is denatured (the molecule falls apart) at that temperature, working best between 131-150F.

 

[stuchambers]

Yes these are the optimum temperatures that allow you to have the mash completed in the 60-90min. thats why I said that the mash time would be 24hrs to give the enzymes time to work at the lower temperature.
Only alpha amylase is present in saliva.

 

[TerritoryBrew]

Yes these are the optimum temperatures that allow you to have the mash completed in the 60-90min. thats why I said that the mash time would be 24hrs to give the enzymes time to work at the lower temperature.
Only alpha amylase is present in saliva.

Hi Stu,

The starch won't convert at room temperature as the enzymes in the grain are not activated at this temp. You are right about amylase being present in saliva, but you would need to introduce this to the mash at room temperature to get any conversion. This is similar to the Peruvian beer as shown in the Master Brewers Program in one of the first five episodes. **Episode 2** Here is a link to the thread.

The enzymes present in grain need to be activated at the right temp. Introducing other commercial enzymes at such a low temperature really does defeat the purpose of mashing and I am not sure as to what sort of conversion you would get.

TB

 

[DanRayner]

Mashing is done at 60-70degC for two reasons:

i) alpha and beta amylase both work at their optimum (as others have noted), and

ii) gelatinisation of starches in malted barley only occurs in this range.

Gelatinisation is the unravelling of (otherwise bound up) starches. What this means is the amylase will go nuts on the surface of your milled grain starch but the complex starch chains aren't unravelled enough for the enzymes to get all of it. You will get some conversion but even in the long run it will amount to sweet FA and, as others has suggested here, you will end up with pretty much what you started with: soggy grain (that's maybe a touch sweeter). Gelatinisation of wheat is much lower 52-54degC hence many people will do a step mash with hefeweizens.

Interestingly, gelatinisation of rice/maize/corn occurs at higher temperatures - around 70-75degC - I guess it's why most people boil rice to cook it. And if you were to use rice/maize/corn in a mash you would need to bring it to this temperature (separately, one would imagine) for a while and then add it to your mash tun.

You don't need to boil malted barley to "cook it" but you do need to bring it to at least 64-67degC.

cheers,

Dan

EDIT: spelling errors, corrected gelatinisation temp for barley malt

 

[Daniel.lear]

Even if there was some conversion, there is heaps of lacto present in malted grain. 24hrs worth of warm sodden grain is going to be rather pungent and probably wouldn't make very good beer to say the least.

Try it and let us know.

Leary

 

[DanRayner]

Ooh, just found this awesome little wiki-article about starch conversion

I might have been a bit off with my rice gelatinisation temperatures but you get the idea.

Reading this it seems you could be on to something with your industrial enzyme use - you could probably use flaked barley/wheat/rice/whatever and then add your "commercially-available" alpha/beta amylases to this room temperature soup.

Dunno how it would taste though (I'm guessing not great) and why re-invent the wheel. We've been doing it this way for hundreds of years for a reason: it works!

 

[big78sam]

The above seems to make sense to me but it did raise a question. How is the proposed different from an overnight cold steep of specialty grains (which I know many have done with some success)?

 

[DanRayner]

Heya Sam,

Many speciality grains are already highly-modified, meaning they have quite a bit of converted starches or sugars in them already. In the higher-temp malting process for some speciality malts the starches are already partially converted into simple sugars - especially caramalts/crystal malts, crack on of those open and you'll see why they're called crystal malt; the body of the grain is crystalline with a fair bit of that being simple sugars.

Othe speciality malts, like roast malts, chocolate malts, etc are really only used for flavour and colour and again conversion of starch is not what you want out of them (in fact there are virtually no starches left in roast malts, it's all charred stuff)

D




edit: introduced myself

 

[MHB]

If youre determined to do this good luck to you.
Just bear in mind that there are something like 30 enzymes that could all easily be acting on your mash, most of these are never encountered by mash brewers because they are denatured well below the normal mash in temperatures. You are quite right in thinking that enzymes will work at temperatures well under the optimum; in fact at low temperatures they will keep working almost indefinitely.
So if you wait long enough, lets ignore the fact that some quite undesirable fractions will go into solution (like polyphenols) and that you are assured of a rising bacteria count (notably Lacto), what will happen if enzymes arent denatured.
Well protease will (given time) degrade all the high molecular weight proteins to short amino acids, guaranteeing that the beer wont hold a head
Starch will be degraded to the shortest possible unit (glucose), the wort will attenuate as far as the yeast will allow. There is a cute little enzyme; limit detrinase that will even chew up the T shaped limit dextrins that contribute quite a lot of body to beer, not something that would happen normally as its denatured quite early.
God knows what else is going to be going on in there or how long it would take the slow working enzymes to mash your malt into solubility; but you wont be making beer, well at least not as we know it Jimmy.
MHB

PS
Couple of points
Any enzyme that degrades starch is called an Amylase, there are two in malt Alpha and Beta, what makes you thing the one in saliva is the same as one or the other, not all flammable liquids are petrol, not all Amylases are the same.
Commercial enzyme are even more finicky and temperature dependant than their natural homologs, and the result will taste different.
M

 

[schooey]

I did an 18 hour acid rest at 35C on a Berliner Weisse just recently. When I went down in the morning and took the lid off I almost... :icon_vomit: It tasted as tart as your mother in laws lipstick too....

Find a better challenge, dude...

 

[Hatchy]

I did a 23 hour mash on the weekend. Mashed in at 63 & it was at 62 after 12 hours which I thought was pretty impressive. I lost 12 degrees over 23 hours which is slightly less impressive. Never again will I mash in when I feel terrible & want to go back to bed. Slightly off topic I know but I reckon the original question has been answered adequately.

 

[stuchambers]

Dan and MHB,

Thank you very much for taking the time to reply you guys seem to have a lot of knowledge and it is great you are willing to share it with me.
I asked the question as I recently tried a small 5L batch all grain my mash in temp was 67 after and hour wrapped in towels the temp was 52ish. I applied heat and then removed the bag at 80 odd. Continued heating and finished the boil as usual with hop additions.
So it was just a thought that if it could be done over a longer period at lower temps that might be easier than mucking around trying to maintain my temp.
I also have a interest in science and like to know how things work.

Once again thanks for all your replies

Cheers Stu

 

[DanRayner]

No worries at all Stu, just been brewing for a while, you'll get there...

Water (and mash water) usually has excellent temperature buffering capacity but and (you probably know this so forgive me) with smaller volumes, like your 5L mash, this capacity to hold temperature drops as the totally energy stored in your smaller vessel (as heat) is correspondingly much smaller. You'll find your mash-tun would hold heat a little better if it were bigger, like a 20-50L vessel. Find a 35L esky and go nuts with a full AG (or BIAB) system

 

[Thirsty Boy]

What you suggest is done pretty regulalry in the asian brewing tradition - enzymes are allowed to act on rice for a very long time at room temperature or even less (with yeast in there at the same time) and somewhere between 2 & about 6 weeks later - the result is rice wine. But if you have enough enzymes, you can reduce a starchy mass to a sugary mash at room temperature overnight.

The trick is the "gelatinization" of starches that has been mentioned previously. In rice wine brewing, this is done by steaming the grain before brewing. Thats all fine if your enzymes are in a different place to your starch as it is with rice wine (they are in the koji or the yeast) - but in malt, they are all tied up in the same package. In order to get the starch usable... You have to heat the grains up to basically the enzymes optimum temps anyway - and if you tried to cool it down again, conversion would nearly be all over by the time you managed it.

Using exogenous enzymes - not only works, it works well enough so there are production breweries out there that do exactly that. Its a bit of a mega brewing fad at the moment to be looking at ways to use unmalted barley rather than malted barley, and a bunch of trials have been done to show that you can produce palatable beer doing it. But for the most part, if its done, its usually done in breweries in africa that are using sorghum and other unmalted local grains to produce their beer. But you can certainly do it with barley too.

I personally have made a couple of small batches of gluten free beer using exogenous enzymes - at least one of them using a basically 24hr room temperature mash. It works - but it doesn't work nearly as well as normal mashing. And you have to do some reasonable mucking about to make sure things dont get all sour and infected. And then the things you have to dick about with trying to make it taste like normal beer.. Sigh. Its the sort of thing I'll do to make a gluten free beer, or as an experiment to learn about mashing and enzymes etc.. But its not even close to the sort of trouble i would be willing to go to to make "normal" beer.

Cheers

Thirsty