Mash Conversion and Time

[jleiii]

I keep seeing recurring comments about Mash Time, and responses about how conversion is done in far less than the hour of mashing, and you can mash for xx minutes and be done. If this was the case, why does everyone do a 1 hour (or more) mash?

Correct me if I'm confused here, but isn't this sort of a 2 step process - converting starches to unfermentable sugar, then breaking down those sugars to fermentable states, where this sugar conversion is directly related to mash temperature, and time.

Every time I see a comment about conversion being done in minutes I cringe, based on my understanding of the process. Yeah, you'll get beer, but is it the beer you were expecting?

Can the 'experts' weight in?

 

[RM-MN]

I'm not an expert on this question but I've been doing experimenting and what I've found is that conversion happens very quickly and while it takes a specific enzyme to do the magic, the two enzymes we as brewers are mostly concerned with seem to work concurrently. If that were not the case and it took much longer to get the unfermentable sugars broken down to fermentable sugars I would end up with beer with a very high FG and almost no alcohol. Instead, I'm finding that the FG is even lower than the software predicts and I've been getting that result with only a 10 minute mash. I can't tell yet if there is any difference in the flavors for all the batches yet because some of them are still in fermenters or in the bottles maturing. The lighter color beers that mature faster seem to taste the same as the batches where I mashed for a full hour. More testing is underway so I'll try to update what I find out from that.

 

[jleiii]

I would think that if an hour (+) mash was not needed, it would quickly be embraced to reduce the time spent during a brew day. Yet, it seems to be only raised here and there with no real definitive answer. Sounds like you are actually investigating it.
Regarding the point about High FG, the temperature is much more critical to this, as that is the primary factor on fermentable vs non-fermantable sugar conversion. Obviously if the time is too short that can cause high FG as well since the conversion would be incomplete.

 

[mbobhat]

In addition to all above said it also has to do with the starches physically dissolving into the wort as well. Or you can call it gelatinizing the starches. The enzymes can't reach it if it is not in the solution like the enzymes are. So there are a couple processes going on, physical and biochemical.

This is the physical reason why the grains are malted, to varying degrees of conversion.

But I agree with the OP in that maybe the conversion is less than an hour but it takes 5-10 minutes to throughly wet and dissolve the starches in the wort? Then conversion happens?

No expert here either but I would guess that's why conversion doesn't happen in 'minutes' Unsoluble Starch to Soluble Starch
Soluble Starch to smaller chain starch
smaller chain to sugars

All happening at the same time?

 

[jleiii]

Mbobhat,
I did do a little refresher reading on this before I posted, and none of the things I read talked about any specific time for mash, but relative - "more time".
You are correct on the dissolving/gelatin part. The grain has to absorb the water initially, and then enzyme action starts, but once any starches are converted to sugars, the further breakdown is happening at the same time. But clearly the starch has to be 100% done before the long chain sugars can be broken down to fermentable ones. This is what gets me wondering when only the starch test is used to know it's 'done'. There could be 0 starch, but still plenty of long chain sugars. In some beers this is desirable, but again more a function of mash temperature.
I'm sure there is a detailed scientific report that can clarify this, but I've not happened upon it yet. Guess it's time to search some more.

 

[jleiii]

Sometimes you hit the right keywords in a search.

A Google Book preview of Brewing: Science and Practice Chapter 4 Mashing.

Clearly time is an important factor, and it's obvious why the 1 hour mash is the standard. Very interesting (and technical) reading. But holy crap, $509 for the book at B&N, and $943 at a specialty book shop!

 

[RM-MN]

Mbobhat,
I did do a little refresher reading on this before I posted, and none of the things I read talked about any specific time for mash, but relative - "more time".
You are correct on the dissolving/gelatin part. The grain has to absorb the water initially, and then enzyme action starts, but once any starches are converted to sugars, the further breakdown is happening at the same time. But clearly the starch has to be 100% done before the long chain sugars can be broken down to fermentable ones. This is what gets me wondering when only the starch test is used to know it's 'done'. There could be 0 starch, but still plenty of long chain sugars. In some beers this is desirable, but again more a function of mash temperature.
I'm sure there is a detailed scientific report that can clarify this, but I've not happened upon it yet. Guess it's time to search some more.

This is part of why I am experimenting. Note that I use a Corona style mill and grind my grains as fine as possible. That gets the particle size down so they get wet through nearly immediately. I worried at first about the iodine test for starches because I was getting a negative reaction within 2 to 3 minutes and I wondered if I was only getting activity with the alpha amylase so while I didn't have starches left, I might have only or mostly unfermentable dextrines or long chain sugars. By fermenting the wort and getting a lower FG than predicted by the software given the OG that I measured with a hydrometer and the mash temperature it seems like both beta and alpha amylase were fully active.

 

[monkeyman1000]

I keep following your postings on this subject RM-MN. Pretty interesting stuff. I cut my last mash time down to 45 minutes to see what would happen and my OG and FG were right on target. It is still in the bottle though so haven't tasted it yet. I am currently at the mercy of the LHBS's mill so my grind isn't as fine as yours. Keep us posted on your results.

 

[RM-MN]

I keep following your postings on this subject RM-MN. Pretty interesting stuff. I cut my last mash time down to 45 minutes to see what would happen and my OG and FG were right on target. It is still in the bottle though so haven't tasted it yet. I am currently at the mercy of the LHBS's mill so my grind isn't as fine as yours. Keep us posted on your results.

I bought my grain mill from Discount Tommy and I think that at his price they are within most brewer's budget. When I got mine to try my first batch (what I'd call my LHBS doesn't have a mill) BIAB I left the software set at 70% efficiency and overshot my expected OG by quite a bit without sparging. Since I know now that my efficiency with a small sparge will be about 85%, I reduce the grain bill to accommodate that and it doesn't take long to pay for the mill. http://www.discounttommy.com/p-189-...er-for-wheat-grains-or-use-as-a-nut-mill.aspx

I'd really like it if someone else would try shorter mash times and either validate or refute my findings. I don't brew often enough to get the control batches to compare whether there is a difference in the short mash times compared to the hour long mashes.

 

[monkeyman1000]

Thanks for the link. It isn't so much the price as it is space. I move every 3-6 months (leaving ID tomorrow for CA) for work and everything has to fit into a hyundai Santa Fe (two of us). That is another reason small batch BIAB works so well for me. I might have some room on the roof but how do I convince the SWMBO.

 

[JohnSand]

I'm following this thread and yours, RM-MN. Thanks for experimenting and posting, please keep us advised. There are currently also discussions by brewers reaching surprisingly low FG with their usual process. Some conclude that modern malts are bred (engineered?) with an eye toward efficiency in commercial brewing, where time is money. That may answer some of this, and in the end, aid homebrewers. Whatever the case, it may take a while, but this could be the next homebrew breakthrough. No secondary, no HSA worries, shorter mash. If it works well it should be called the "RM-MN Method".

 

[masonsjax]

After hearing that Lagunitas mashes for only 20mins, I started experimenting. I did a lot of batches with only a 20-30 min mash with good results. I noticed that at the same temperature the wort is slightly less fermentable at 20 mins so I adjust the temp down a couple of degrees to compensate. At 30 mins it seems to have the same result as a 60-90 min mash. I didn't document anything and it's been very unscientific, but my results seem to support the idea of a long mash not being essential.

There's also been some talk recently of modern grain, 2-row in particular, being much less responsive to mash temp than previously. Someone here has done experiments mashing 2-row at both extremes of the temperature range and ending up with nearly identical wort. Just another point to keep in mind.

 

[masonsjax]

After hearing that Lagunitas mashes for only 20mins, I started experimenting. I did a lot of batches with only a 20-30 min mash with good results. I noticed that at the same temperature the wort is slightly less fermentable at 20 mins so I adjust the temp down a couple of degrees to compensate. At 30 mins it seems to have the same result as a 60-90 min mash. I didn't document anything and it's been very unscientific, but my results seem to support the idea of a long mash not being essential.

There's also been some talk recently of modern grain, 2-row in particular, being much less responsive to mash temp than previously. Someone here has done experiments mashing 2-row at both extremes of the temperature range and ending up with nearly identical wort. Just another point to keep in mind.

 

[jleiii]

Interesting stuff coming by here. The book I noted above is not real recent, citing references from the 90's back to the 40's. Maybe modern malts are no longer comparable to those studies.
I don't get to brew very often either, but really want to do small batches which do go faster, so I'll try to experiment. Be nice to have several small pots for this.

 

[FatDragon]

I'm definitely interested in this myself. I want to start getting into some one-gallon BIAB batches for recipe testing and increased variety, and shortening the mash time would be an ideal way to make such a bit more economical in terms of time invested to beer ingested. I asked in the one-gallon thread, but didn't get any bites, but I knew that RM-MN was doing some good work here, which led me to stumble on this thread with more of his commentary.

Hopefully, in a few months I'll be able to start doing some of my own experimentation in the matter. If I do, I'll be sure to share my results.

 

[C-Rider]

I mash between 60 & 75 min. At the 1/2 way point I'm usually only about 1/2 way to the expected pre-boil SG so I can't figure how anyone could be done w/the mash in 10-15 minutes. I must be doing something wrong. I BIAB, 2 gallon batches using approx 2.8 gallons of water and 4-5 lbs of grain in a 5 gallon Colman cooler.
I double mill at the LHBS.

Here is a quick look at mash times and SG for a few brews. Big difference between the 30 min and the 60 min readings.

 

[masonsjax]

I don't know much about BIAB, but maybe your samples were not representative of the wort when fully sparged and mixed? The 4.75 lb line for instance has a dip in efficiency before climbing back up. My personal experimentation with full mashes has been very good.

From what I have found, the sugars are created very quickly, and although Beta Amylase works slower than Alpha, the conversions are all going on simultaneously. Because of the slower breakdown of complex sugars to simple sugars than the conversion of starch to long-chain sugars, you can use the duration of the mash much as you would traditionally use mash temperature to create a more or less fermentable wort. A very short mash (IME) will tend to be slightly less fermentable than a 60+ minute mash, given the same mash temperature. A combination of a shorter mash at a lower temperature seems to average out to the same gravity and fermentability as a long mash performed at a few degrees hotter. For an extremely unfermentable wort, you could do a short mash at the upper temperature extremes, for an ultra dry beer, mash for a long time at the lowest end of the range. Given today's extremely modified malts, mash duration might be a more reliable way to dial in wort fermentability.

 

[RM-MN]

This batch hasn't been bottled yet as I was giving it plenty of time to ferment out but here's some info that seems to be pertinent to this discussion. This is an amber ale somewhat like Fat Tire.
5.25 lbs of grain in 3.75 gallons of water mashed at 156.5 for 10 minutes. OG was 1.050 for a brewhouse efficiency of about 80%, Brewed on 2/4/2014 and on 3/7/2014 the gravity was down to 1.002. Those numbers seem to mean that the efficiency was pretty high at 80% and that the wort was very fermentable too. The yeast used was a half package of Danstar Windsor.

 

[RM-MN]

I mash between 60 & 75 min. At the 1/2 way point I'm usually only about 1/2 way to the expected pre-boil SG so I can't figure how anyone could be done w/the mash in 10-15 minutes. I must be doing something wrong. I BIAB, 2 gallon batches using approx 2.8 gallons of water and 4-5 lbs of grain in a 5 gallon Colman cooler.
I double mill at the LHBS.

Here is a quick look at mash times and SG for a few brews. Big difference between the 30 min and the 60 min readings.

I think the only thing you are doing wrong is milling the grains at the LHBS. If you're getting more conversion/extraction of sugar up to 75 minutes after you dough in, your grain particles must be quite large. If it takes 30 minutes for the water to reach the center of the particle of grain, it probably takes that long to get the sugar leached back out. If you have a food processor, try milling your double crushed grains in that and see if you are still getting sugars out at 60 minutes when you mash that. Don't process until you get nothing but flour but do break up the grains.

 

[masonsjax]

Also, the necessary amount of time required for full conversion is very dependent on the diastatic power of your grist. If you have a high percentage of adjuncts that can't convert themselves, you should be mashing longer to compensate. A 2-row SMaSH could be done in 10 mins perhaps.

 

[ArcLight]

If you BIAB you can afford to crush much finer than if you use a conventional cooler and false bottom because you will get a stuck sparge. Also, purchases crushed grain is sometimes poorly crushed.

Because users of a false bottom can't risk crushing too fine, extra time must be allowed for gelatinization.
There is no harm to mashing for an hour compared to a shorter time, though it might not make much difference. On the other hand, I don't have to stand there while it's mashing. If I come back 45 minutes later or 60 minutes later of 75 minutes later, it's all the same to me.

Also, the reason to mash for an hour is if you undershoot your temperature and mash a couple of degrees cooler, the Alpha amylase is working much slower, and you will have less fermentable wort.

The other thing is the hotter you mash, the less time you need, because the beta amylase is being destroyed, and there is so little left that the extra time doesn't gain much.

Next time I brew I will tighten up my mill even more. I do BIAB and get pretty good efficiency as it is, close to 80%.


>>5.25 lbs of grain in 3.75 gallons of water mashed at 156.5 for 10 minutes. OG was 1.050 for a brewhouse efficiency of about 80%, Brewed on 2/4/2014 and on 3/7/2014 the gravity was down to 1.002. Those numbers seem to mean that the efficiency was pretty high at 80% and that the wort was very fermentable too. The yeast used was a half package of Danstar Windsor.


I find that very hard to believe. That yeast is not a highly attenuative yeast (like distillers yeast) and to get a 96% attenuation - I'm skeptical. I could believe it if sugar was added. Or there was an infection.

Ask yourself this "why are you the only one getting that high an attenuation"? No one I know, and in no articles I've read, does anyone get 96% attenuation - unless the grainbill included extra sugar or uses a highly attenuative yeast.

 

[C-Rider]

I think the only thing you are doing wrong is milling the grains at the LHBS. If you're getting more conversion/extraction of sugar up to 75 minutes after you dough in, your grain particles must be quite large. If it takes 30 minutes for the water to reach the center of the particle of grain, it probably takes that long to get the sugar leached back out. If you have a food processor, try milling your double crushed grains in that and see if you are still getting sugars out at 60 minutes when you mash that. Don't process until you get nothing but flour but do break up the grains.

Could be the mash. I may try to borrow a friends mill..He has yet to try it as he's doing Extract 99% of the time.

 

[RM-MN]

If you BIAB you can afford to crush much finer than if you use a conventional cooler and false bottom because you will get a stuck sparge. Also, purchases crushed grain is sometimes poorly crushed.

Because users of a false bottom can't risk crushing too fine, extra time must be allowed for gelatinization.
There is no harm to mashing for an hour compared to a shorter time, though it might not make much difference. On the other hand, I don't have to stand there while it's mashing. If I come back 45 minutes later or 60 minutes later of 75 minutes later, it's all the same to me.

Also, the reason to mash for an hour is if you undershoot your temperature and mash a couple of degrees cooler, the Alpha amylase is working much slower, and you will have less fermentable wort.

The other thing is the hotter you mash, the less time you need, because the beta amylase is being destroyed, and there is so little left that the extra time doesn't gain much.

Next time I brew I will tighten up my mill even more. I do BIAB and get pretty good efficiency as it is, close to 80%.


>>5.25 lbs of grain in 3.75 gallons of water mashed at 156.5 for 10 minutes. OG was 1.050 for a brewhouse efficiency of about 80%, Brewed on 2/4/2014 and on 3/7/2014 the gravity was down to 1.002. Those numbers seem to mean that the efficiency was pretty high at 80% and that the wort was very fermentable too. The yeast used was a half package of Danstar Windsor.


I find that very hard to believe. That yeast is not a highly attenuative yeast (like distillers yeast) and to get a 96% attenuation - I'm skeptical. I could believe it if sugar was added. Or there was an infection.

Ask yourself this "why are you the only one getting that high an attenuation"? No one I know, and in no articles I've read, does anyone get 96% attenuation - unless the grainbill included extra sugar or uses a highly attenuative yeast.

I find it hard to believe too, but it seems to be repeatable and without off flavors. I thought of infection so I bought new buckets to ferment in and got the same results but no off flavors. The wort is boiled, cooled, and immediately poured into the fermenter bucket and the lid snapped on with an airlock installed. Where else can I be getting an infection from? I do not use sugar on any batch I have made so far and I'm getting similar attenuation on all batches.

 

[ArcLight]

As an experiment, one of these days (in the spring or summer) I'll set my mill very very tight, and see how it affects the fermentability, and efficiency.
Can I get 90% brew house efficiency?
Can I get 90% attenuation with Wyeast 1056.

I have one other theory - maybe with a very tight crush, some of the very fine particles are leaking through the bag, and causing the gravity reading to show up as higher than it really is. When these particles settle into the trub the true starting gravity is actually much less.
This would throw off both the efficiency reading, and the attenuation reading.

 

[wobdee]

I find it hard to believe too, but it seems to be repeatable and without off flavors. I thought of infection so I bought new buckets to ferment in and got the same results but no off flavors. The wort is boiled, cooled, and immediately poured into the fermenter bucket and the lid snapped on with an airlock installed. Where else can I be getting an infection from? I do not use sugar on any batch I have made so far and I'm getting similar attenuation on all batches.

Could your thermometer be off? I just found mine to be 3 degrees low when I compared it to a thermocouple reading. This probably explains my somewhat higher FG's I've been getting.


Sent from my iPhone using Home Brew

 

[RM-MN]

I have 4 thermometers that match including a lab grade glass thermometer so I don't think it is a thermometer problem but they all could be reading high too. I've been raising the mash temperature to see if that solves the overattenuation but at this point it doesn't seem to make much difference. I do have one in the fermenter that I mashed at 158 and another that was mashed at 161 but they haven't been in the fermenter long enough to be at FG yet. More info to come when I sample those.