10 Minute Mash? Mind Blown...

Ok, stumbled across this casually mentioned in a recent thread. . . seems hard to argue with. I'm going for it. Time is so short for me that saving an hour is revolutionary. . . Let me know what you think (Thanks for the info RM-MN)

RM-MN said:

If you feel the need to do the PID controlled recirculation you need to keep the bag off the element as direct contact will burn a hole. My point was that if your grains are milled fine, the time for conversion will be so short that the temperature drop will be so little that adding heat will be pointless. With my system I've found that conversion only takes about 3 minutes. I continue to mash for 10 minutes just to be sure that the beta amylase has time to complete. That's all.

Click to expand...

RM-MN said:

The last batch I did took me 2 hours, ten minutes from starting to bring equipment up from the basement to having it all cleaned and put away except for the items that I washed and weren't quite dry yet. That included weighing and milling the grain. With a bigger heating unit I suspect that 2 hours would be possible. I did a no-chill so I didn't have to wait for the wort to cool, dumped the boiling hot liquid into the fermenter bucket and pitched when it cooled.

That kind of shoots a hole in the PID controller. I'm sorry.

Click to expand...

RM-MN said:

Very few do a 10 minute mash because we've all been brought up on the necessity of a 60 minute mash. Once I heard about a 20 minute mash someone did, it piqued my interest and I had to try some things. The first was a 20 minute mash and behold, I got full conversion as evidenced by hitting the predicted OG. Then I got my hands on some iodine to test for conversion with the idea that I would test at dough in and again every 5 minutes until the iodine quit changing color. On the first sample I missed my 5 minute timing and tested at 7 minutes with no color change in the iodine. That led me to try again and this time I would be more careful about the time and sample every minute from dough in until the iodine quit changing color. By 3 minutes it was done. Being a bit sceptical, I let the mash sit until 10 minutes had gone by just in case and hit the projected OG again.

With only 10 minutes and using nearly the full volume of water there will be little temperature drop unless you are brewing where it is very cold. Even then, if your conversion is done in 3 minutes, that temperature drop would be moot. Please note that you can only be assured of full conversion so fast if your grains are milled very fine. Larger particles take longer to wet through and until that happens, conversion doesn't.

Click to expand...

There is some really good information here:

https://www.homebrewtalk.com/f128/time-needed-starch-sugar-conversion-mash-464039/

You may be interested in this thread.

https://www.homebrewtalk.com/showthread.php?t=487453

If only I could get a decoction mash down to 10 min.

How does this affect Ph adjustments? I put some grain in, stir, put some grain in, stir, put some grain in, stir, then stir some more for about 2 minutes. This process takes 5-10 minutes. If everything is converted in 3 minutes, or even 10, does adding my acids after mashing and stirring even matter? Should I be adding adjustments (based on EZwater or B'run) before mashing in? I take my Ph reading at 15 minutes.

And, IMO, that's part of the fallacy of this process. Also, there is more than the easy to convert starches that need to be converted or unbound. I'm sticking with the longer mash as it is a time proven process. If it weren't, breweries would be doing this as turnover is $$$. That old process is hogging valuable real estate.. They do it for a reason.

ParanoidAndroid said:

How does this affect Ph adjustments? I put some grain in, stir, put some grain in, stir, put some grain in, stir, then stir some more for about 2 minutes. This process takes 5-10 minutes. If everything is converted in 3 minutes, or even 10, does adding my acids after mashing and stirring even matter? Should I be adding adjustments (based on EZwater or B'run) before mashing in? I take my Ph reading at 15 minutes.

Click to expand...

I think this is evidence that you really can't adjust your pH based on measurements of the current mash. By the time you are measuring at 15 minutes most of the conversion has taken place and adjusting the pH at that point is considerably less useful. It is a matter of measuring for the purpose of adjusting the recipe the next time you brew it. So yes, you should be adding your adjustments based on the calculators + your previous experience, if any, with that recipe. This is occasionally pointed out in the big "Primer" thread but is often glossed over.

HopSong said:

And, IMO, that's part of the fallacy of this process. Also, there is more than the easy to convert starches that need to be converted or unbound. I'm sticking with the longer mash as it is a time proven process. If it weren't, breweries would be doing this as turnover is $$$. That old process is hogging valuable real estate.. They do it for a reason.

Click to expand...

Hey HopSong. Not trying to pick on you, but why don't you give a short (20 or 30 minute) mash a try and let us know your results? Do some blind taste tests, etc. Don't take someone's word for it on either the long or short mash. After all, the reason people didn't sail off into the horizon is because the world was flat.

No sir.. thank you. I've spoken to pro brewers about this very thing.. which I alluded to in my prior post. They would not consider it. And as mentioned.. if it were valid, they, of all people would have EVERYTHING to gain. YMMV

Interesting. I have noticed a significant difference in the consistency of the mash throughout the 60 minutes - I don't have anything concrete and can't refute the experience of others, but at 10 minutes into the mash I'm still seeing visible changes happening, so it makes me think there is still something of value going on...

I'm with HopSong on this. How is mash completion being determined? Iodine test?

Iodine only accounts for amylose conversion which is only 20-30% of the grist. How is one determining that the amylopectins (70-80% of grist) have been taken care of?

Mashing involves:
leaching of preformed soluble materials from the grist (products of malting)
extraction of substrates from the grist and enzymes from the malt
enzyme action
chemical interactions between the mash components

For example, calcium needs to react with phosphate to lower the pH and with oxalic acid. Failure to remove oxalic acid leads to the risk of its precipitating in beer to cause gushing and haze.

Gelatinization also takes time (5 to 10 minutes after dough in)

There is a lot more to the mashing process than just getting a good conversion indication. Breweries are not going to spend one additional minute on a process than they need to...it's all about throughput and all of the brewers I have asked mash for at least 60 minutes, many for up to 120 minutes although the mash studies I have read indicate that 60 minutes is quite adequate.

Me. too.

There are things that are happening in the mash over time that aren't apparent. For example, the character of the sugars in the wort.

Maltotriose (which isn't completely fermented by ale yeast), maltose, sucrose, etc, all play a role in the final quality of the beer. While starch conversion can happen in 10-20 minutes, the debranching of amylopectins continues.

pH plays a big role in this as well.

I've been reading and re-reading Briggs' "Brewing Science and Practice" and I think we totally simplify what is happening in the mash. Conversion, as shown by iodine tests and SG readings, doesn't mean the wort is "done", and some of the sugars will reduce to simpler sugars during the continuing mash. http://books.google.com/books?id=mR...nepage&q=mash amylopectin debranching&f=false here for an excerpt from the book on that.

Much of what is discussed in this thread is given as absolutes but they are not. Gelatinization does not always take 5 to 10 minutes but is dependent on the size of the grain particles. Also, starch conversion depends on the gelatinization time and will vary with particle size too. My iodine tests show starch conversion in less than 3 minutes, not the 10 to 20 minutes that Yooper finds.

How much of the big brewers activity is based on science and how much is based on "this is how we've always done it". Throughput is critical to their operation but mash time isn't part of the worry as the difference in 30 minutes to 120 minutes doesn't have nearly the effect on throughput as the time the yeast need. Once you have filled all your fermenters, you wait until the yeast is done before you need to mash again. For me, brewing is not my job but a hobby that I like to do but some days I need to do a few other things and can't devote an entire day to brewing like some of you do. If I can shorten a brew day, I can brew on days when I have other jobs to do too.

I'm not going to say definitively that my mash is completed in 10 minutes but I will say that it doesn't need 2 hours unless your milling is really poor. I'll continue to experiment with short mashes unlike some of you who are unwilling to make any changes from "how it's always done" and I'll report on any success or failures I find.

Professional brewing is a business. Regardless if craft, or BMC. They could save millions of dollars by shortening their mashing processes. They have molecular scientist and process engineers reviewing their techniques every day. So the "this is how it's always done" argument holds no water. Do what you want, but I'll stick to what the big boys do, and what works for me.

A local pro Brewer mentioned in a post on ahb that he does and will stick with 20minute mashes.

Hammy71 said:

They could save millions of dollars by shortening their mashing processes.

Click to expand...

I'm fairly ignorant of the professional folks' processes as I'm new to brewing and have only ever done BIAB. But I'm gonna play a little devil's advocate here.

As someone pointed out, brewing beer is a batch process and the bottleneck is usually fermenter space (which just so happens to be a lot of home brewers' bottleneck as well). If it is true that the mash is not a process bottleneck and therefore is not the limiting factor on throughput, then a shorter mash would not allow commercial breweries to make more beer and then more money.

So exactly how would they save money with a shorter mash? Are there fuel costs involve? Electricity to run pumps and what-not? You'd have to pay someone to baby sit the mash I suppose. But an hourly worker (or 5) hardly seems like a huge cost to a big operation.

Given this I would conclude that the commercial folks have little to no motivation to shorten their mash times in order to save or make more money. I would also conclude that they have the mash times they do because either a) they have scientific data that tells them to do it that way, or b) they've just always done it that way.

All right folks! Tell me where my logic fails me on the money issue. The rest is still up for debate.

Oh wait. I almost forgot. While I am ignorant of commercial beer making processes, I am all too familiar with hydrocarbon processes. As a process engineer I am often working with refinery personnel to get an understanding of their operations and help them troubleshoot or develop new projects. I bring this up only because more often than not, when you ask why they do something a certain way, the answer is "that's how we've always done it".

Unfortunately the rationale for certain actions has been lost as people retire, quit etc. I'm sure at some point in the past there was a very good reason, but things change. So then it is my duty to help them see a new way of doing things.

Keep in mind these refiners are multi billion dollar companies, some of the largest companies in the world, and employ the best and brightest scientist and engineers that money can buy. Yet even they sometimes get caught up in the trap of "that's how we've always done it".

This anecdote doesn't resolve our issue at hand, but hopefully will help us move past the justification of "that's how the commercial folks do it". The commercial folks aren't always right.

There are many reasons why a commercial brewery would need an hour long mash. First is their setup. They have spent the money to get the equipment that works with a particular milling of their grain. They aren't going to replace it all to go to a bag (BIG! bag) so they can mill finer. Second is the milling. They have a mill that works. Why replace it? Third is scale. I can get all my grains mixed in within 30 seconds. Try that with a 4 story mash tun!

RM-MN said:

There are many reasons why a commercial brewery would need an hour long mash. First is their setup. They have spent the money to get the equipment that works with a particular milling of their grain. They aren't going to replace it all to go to a bag (BIG! bag) so they can mill finer. Second is the milling. They have a mill that works. Why replace it? Third is scale. I can get all my grains mixed in within 30 seconds. Try that with a 4 story mash tun!

Click to expand...

Good points. Helps drive home that home brewers shouldn't always do what the commercial folks do. Sometimes it makes sense, other times it doesnt.

On a slightly different topic, I'd be interested to know how the three vessel set up became so popular with home brewers. Is it because it mimics what the commercial folks use? If I were developing a small scale brew process from scratch I don't think I'd end up with the three vessel approach.

Not at all trying to pick on the three vessel users. Just genuinely curious on the history of this stuff and how it might help us make better decisions in the future.

so is this is the same theory behind 10 min rice? crack the grains to allow the steep to get through the rice quicker allowing a shorter time to cook?

Inertia is a powerful force. The bigger the company, the more robust the traditions...

One important distinction that both RM-MN and TexasWine allude to is different equipment and the needs of that equipment. Big breweries are using conventional mash tuns. They require larger particle size to work correctly.

The question is, if a BIAB brewer pulverizes the grain, can we shorten our process without sacrificing some of the qualities we are looking for in the finished beer?

It is ridiculous and more than a little shocking how all of these posts, where someone reports their ACTUAL RESULTS, are constantly refuted by people with answers like "well someone wrote a book that said it's not good" or "that's not how the pro's do it"...

What? Who cares?

Try it for yourself. Check gravity and FG when the ferment is done.

I will add my experience again- I get full gravity (average 84% efficiency) AND full, even High attenuation (80+%)with a 30 minute mash with a tight crush.

Next I'll test an even shorter mash. 30 minutes was as short as I could stand while I did shorter and shorter tests, but based on the results, I should test even shorter.

The beer is as good or better than when I got 68% efficiency and 75-80% attenuation in a full hour long cooler mash plus mash out, sparge, etc.

I tried 90 minute mashes and got good efficiency, but close to 96+% attenuation. I got many, many 1.004 - 1.000 FG's.

With the exact same process and a 30 minute mash I get "normal" 80%-ish attenuation.

YMMV. That's why I recommend a test.

RM-MN said:

Much of what is discussed in this thread is given as absolutes but they are not. Gelatinization does not always take 5 to 10 minutes but is dependent on the size of the grain particles. Also, starch conversion depends on the gelatinization time and will vary with particle size too. My iodine tests show starch conversion in less than 3 minutes, not the 10 to 20 minutes that Yooper finds.

How much of the big brewers activity is based on science and how much is based on "this is how we've always done it". Throughput is critical to their operation but mash time isn't part of the worry as the difference in 30 minutes to 120 minutes doesn't have nearly the effect on throughput as the time the yeast need. Once you have filled all your fermenters, you wait until the yeast is done before you need to mash again. For me, brewing is not my job but a hobby that I like to do but some days I need to do a few other things and can't devote an entire day to brewing like some of you do. If I can shorten a brew day, I can brew on days when I have other jobs to do too.

I'm not going to say definitively that my mash is completed in 10 minutes but I will say that it doesn't need 2 hours unless your milling is really poor. I'll continue to experiment with short mashes unlike some of you who are unwilling to make any changes from "how it's always done" and I'll report on any success or failures I find.

Click to expand...

What about you RM-MN? Have you had good attenuation on 10 minute mashes? I recently did a 30 minute mash (it wasn't biab) and the beer attenuated to where I had planned given the grain bill and the yeast. I will have to look up the exact numbers but I believe it was 78% apparent attenuation.

Aplikowski said:

Inertia is a powerful force. The bigger the company, the more robust the traditions...

One important distinction that both RM-MN and TexasWine allude to is different equipment and the needs of that equipment. Big breweries are using conventional mash tuns. They require larger particle size to work correctly.

The question is, if a BIAB brewer pulverizes the grain, can we shorten our process without sacrificing some of the qualities we are looking for in the finished beer?

Click to expand...

This just isn't true...ABInBev uses mash filters with grain pulverized by a hammer mill, they lauter using pressure making it very fast since no grain bed is involved. The mashing and sparging process is a huge bottleneck because for back-to-back brews 24/7 the mash tun needs to be available as quickly as possible.

The big brewhouses have PhD biochemists, microbiologists, chemical engineers, etc. and they do not do anything just because that's the way it was always done

With well modified grain there is no difference in extraction between fine grind and course grind, or thin vs thick grist ratios, this has been demonstrated by Kai and written about Effects of Mashing Parameters on Mash B-Glucan, FAN and Soluble Extract Levels, Kuhbeck, Dickel, Krottenthaler, Back, Mitzscherling, Delgado, and Becker, 2005

What I have not heard from the very short mash brewers is the difference in haze stability, flavor stability, or foam stability....these are significant things and the reactions that effect them all take place in the mash. I know there are visual, physical changes going on in my mashes through the first 30 minutes then I determine conversion completion by SG readings.

With well modified grain there is no difference in extraction between fine grind and course grind, or thin vs thick grist ratios, this has been demonstrated by Kai and written about Effects of Mashing Parameters on Mash B-Glucan, FAN and Soluble Extract Levels, Kuhbeck, Dickel, Krottenthaler, Back, Mitzscherling, Delgado, and Becker, 2005

Click to expand...

If this is true, the why would ABInbev pulverize their grain and why do we suggest the crush of the grain is at fault when people get poor efficiency?

What about you RM-MN? Have you had good attenuation on 10 minute mashes? I recently did a 30 minute mash (it wasn't biab) and the beer attenuated to where I had planned given the grain bill and the yeast. I will have to look up the exact numbers but I believe it was 78% apparent attenuation.

Click to expand...

I've been getting very high attenuation but I blamed that on a wild yeast because of one batch that came to a proper FG, remained there for a week, then when I bottled it I got bottle bombs from that batch. Another batch attenuated properly but after I had opened it and dry hopped it began fermenting again, going down from 1.017 to 1.002 in the course of 2 weeks. My house has little air exchange during the winter and I decided that a wild yeast was pervasive in my air so this summer I had windows open as often as possible with the hopes that I could get the yeast out of the air in my house. I haven't brewed since April and don't expect to for at least a few more days as I have jobs that need done before winter arrives. Working 7 days a week doesn't leave much time for brewing.

I've been with RM-MN on this subject for a while. Granted, there are a lot of things going on in the mash besides starch extraction and enzymatic conversion, BUT the proof is in the pudding. Good beer has been made. When you double crush, it does not take long at all to gelantize the malt...How long did it take your Frosted Flakes as a child to turn to mush in milk? And conversion is momentary, from personal experience, once the starches are freed.

However, its not for everyone. I strongly hold to the theory that people should do what works for them. Having comfort in your process is as important as anything. But if you are trying to shorten your brew day, give it a try. Buy a bag, grind the grain to near powder, and shorten your mash time.

helibrewer said:

This just isn't true...ABInBev uses mash filters with grain pulverized by a hammer mill, they lauter using pressure making it very fast since no grain bed is involved. The mashing and sparging process is a huge bottleneck because for back-to-back brews 24/7 the mash tun needs to be available as quickly as possible.

The big brewhouses have PhD biochemists, microbiologists, chemical engineers, etc. and they do not do anything just because that's the way it was always done

With well modified grain there is no difference in extraction between fine grind and course grind, or thin vs thick grist ratios, this has been demonstrated by Kai and written about Effects of Mashing Parameters on Mash B-Glucan, FAN and Soluble Extract Levels, Kuhbeck, Dickel, Krottenthaler, Back, Mitzscherling, Delgado, and Becker, 2005

What I have not heard from the very short mash brewers is the difference in haze stability, flavor stability, or foam stability....these are significant things and the reactions that effect them all take place in the mash. I know there are visual, physical changes going on in my mashes through the first 30 minutes then I determine conversion completion by SG readings.

Click to expand...

How would I go about testing the stability parameters you mentioned? Just via observation? I think we could get some decent data and put this to the test.

You'd first need to point us to the info that equates mash time, and time alone, as the secret to foam and flavor stability. I'd need an explanation of what 'haze stability' stability is as well.

I mash for 30-45 minutes. Because that's how long it takes me to put the mill away, get hops weighed and ready, some cleanup, etc. That's my process.

Weezy said:

You'd first need to point us to the info that equates mash time, and time alone, as the secret to foam and flavor stability. I'd need an explanation of what 'haze stability' stability is as well.

I mash for 30-45 minutes. Because that's how long it takes me to put the mill away, get hops weighed and ready, some cleanup, etc. That's my process.

Click to expand...

Since he hasn't replied I have considered the overall question of quality a lot today. I have devised an experiment to test the noticeable differences of shorter mashes, if any. My plan is to use my cooler to create a pale ale with no sparge. At 15 minutes I will check for conversion with iodine and if it is converted then I will draw off one gallon of runnings. Then I will draw off one gallon at 30 and 60. Might have to up it to 1.5 gallons at each to get approximately 6 beers as well as enough for 2 hydrometer tests out of each round.

Then I will boil each for 1 hour and add the same amount of hops to each. Ferment them all in my ferm chamber at the same temp. Bottle using carb tabs and check one bottle of each every month for six months and see if I can tell a difference. I figure pictures would help determine any physical differences in foam/haze.

Can anyone see a flaw in my methodology? I know I won't be able to test limit of attenuation with such a small sample but I figure actual attenuation using the same yeast from the same packet will get me the info I need to notice a difference.

kaconga said:

Can anyone see a flaw in my methodology? I know I won't be able to test limit of attenuation with such a small sample but I figure actual attenuation using the same yeast from the same packet will get me the info I need to notice a difference.

Click to expand...

Yes. The flaw I see is that the mashes are not the same, if a gallon of runnings is drawn off. The mash thickness, for example, would be different and probably the mash pH would vary too when taking wort off but not grain.

In order for them to be the same, three mashes need to be done, side by side. The same grainbill, the same volume, the same pH, etc. Then, one mash for 15 minutes, one for 30 minutes, and one for an hour would be a valid test. You still couldn't see the sugars that you get out of them, but the FG might be a good test as to which mash produces more maltriose than the others.

kaconga said:

Since he hasn't replied I have considered the overall question of quality a lot today. I have devised an experiment to test the noticeable differences of shorter mashes, if any. My plan is to use my cooler to create a pale ale with no sparge. At 15 minutes I will check for conversion with iodine and if it is converted then I will draw off one gallon of runnings. Then I will draw off one gallon at 30 and 60. Might have to up it to 1.5 gallons at each to get approximately 6 beers as well as enough for 2 hydrometer tests out of each round.

Then I will boil each for 1 hour and add the same amount of hops to each. Ferment them all in my ferm chamber at the same temp. Bottle using carb tabs and check one bottle of each every month for six months and see if I can tell a difference. I figure pictures would help determine any physical differences in foam/haze.

Can anyone see a flaw in my methodology? I know I won't be able to test limit of attenuation with such a small sample but I figure actual attenuation using the same yeast from the same packet will get me the info I need to notice a difference.

Click to expand...

Since it only takes a drop or 2 of wort, may I suggest you test for conversion with iodine starting at 1 minute and each minute past that until you show conversion? If you show conversion earlier than 10 minutes, draw off your gallon at 10, 20, 30, and 60.

With my fine grind with the Corona mill I find conversion in less than 3 minutes with iodine. I've tried 10, 20, 30, and 60 minutes but not from the same batch but I can't say I have noticed much if any difference in the beers. I'd like someone else to give the short mashes a try to see if I'm onto something or just "on" something.

Yooper said:

Yes. The flaw I see is that the mashes are not the same, if a gallon of runnings is drawn off. The mash thickness, for example, would be different and probably the mash pH would vary too when taking wort off but not grain.

In order for them to be the same, three mashes need to be done, side by side. The same grainbill, the same volume, the same pH, etc. Then, one mash for 15 minutes, one for 30 minutes, and one for an hour would be a valid test. You still couldn't see the sugars that you get out of them, but the FG might be a good test as to which mash produces more maltriose than the others.

Click to expand...

I had considered that option yooper, but figured three separate mashes would actually create more variables than one mash with varying times. As you are more experienced than I, I will defer to your judgement on this and go with three separate mashes with the same grain bill and water ratio. Then, if this yields inconclusive results, I will try the one mash method and see how that differs.

RM-MN said:

Since it only takes a drop or 2 of wort, may I suggest you test for conversion with iodine starting at 1 minute and each minute past that until you show conversion? If you show conversion earlier than 10 minutes, draw off your gallon at 10, 20, 30, and 60.

With my fine grind with the Corona mill I find conversion in less than 3 minutes with iodine. I've tried 10, 20, 30, and 60 minutes but not from the same batch but I can't say I have noticed much if any difference in the beers. I'd like someone else to give the short mashes a try to see if I'm onto something or just "on" something.

Click to expand...

My goal is to first determine if shorter mashing does produce similar results. Then I can toy around with how short I can go. For this experiment I will use the standard crush from my lhbs as that is my current baseline and I don't want to introduce more variables than I have to.

I'd think the mash and pH would be stable to permit drawing off multiple times from a single mash if its full volume, no sparge. The thickness would consistent and pH could be monitored as well.

Hydrometer samples to test extraction and conversion rates at certain intervals won't change anything in the mash.

You'll see right away what effect the shorter or longer mash times have on extraction, conversion, and efficiency. If your extraction/conversion efficiency was similar, then on a future batch it's worth testing shorter mash times, knowing you're not losing anything OG-wise.

If extraction was significantly lower for the shorter mash time(s), you probably won't want to do it that way in the future, even if the attenuation is similar.

Then you can ferment the full "long" mash batch and you will have answered the "what effect does a longer mash have on ____" questions (such as attenuation, head retention, etc).

That will knock out about 80% of the questions on one batch.

Magnus314 said:

Hydrometer samples to test extraction and conversion rates at certain intervals won't change anything in the mash.

You'll see right away what effect the shorter or longer mash times have on extraction, conversion, and efficiency. If your extraction/conversion efficiency was similar, then on a future batch it's worth testing shorter mash times, knowing you're not losing anything OG-wise.

If extraction was significantly lower for the shorter mash time(s), you probably won't want to do it that way in the future, even if the attenuation is similar.

Then you can ferment the full "long" mash batch and you will have answered the "what effect does a longer mash have on ____" questions (such as attenuation, head retention, etc).

That will knock out about 80% of the questions on one batch.

Click to expand...

Well my understanding is that a hydrometer/refractometer can only tell you how much sugars you have, not the make up of those sugars. So you can have two samples of 1.050 wort but one might be mostly dextrins and the other could be mostly glucose. This will drastically alter the FG of the sample and is one of the concerns with short mash times.

I am not to the point RM-MN is, where I can be certain conversion can happen in 3-10 minutes with the right crush. But I believe some beers may not only be good enough with shorter mashes but might actually benefit from them. But that is just conjecture at the moment. The real test will be what exactly happens when mash time is changed while all other variables remain constant. If that can be nailed down then mash time can move from being an absolute (one hour) to another tool used to adjust the beers we make.

To those that are saying they will continue to do 60 minutes because that's what pro brewers do, many pro brewers, including me do not do 60 minute mashes. This actually came up the other day on pro brewer.
http://discussions.probrewer.com/showthread.php?41266-10-minute-mash&highlight=minute

Demon said:

To those that are saying they will continue to do 60 minutes because that's what pro brewers do, many pro brewers, including me do not do 60 minute mashes. This actually came up the other day on pro brewer.
http://discussions.probrewer.com/showthread.php?41266-10-minute-mash&highlight=minute

Click to expand...

Oh man. This is great! My favorite part...

"Haha this is why I always get a kick out of homebrew/nano setups where the guy's all "Check out my sweet HERMS!"

Uh huh.
And are you using severely undermodified malt in a mash tun the size of a swimming pool?
No?
So you realize conversion is basically over in a couple minutes right? And you're mostly just wasting time?
No?
You also realize that a percent or two increase in efficiency will save you about 50 cents?
No?
Well at least you have disposable time and income. Say, does that mean your fermenters are glycol jacketed too? Or in a controlled fridge or something?
No?
Sigh."

Brewed a Pils with Best Pils malt the other day and the iodine said it was done in 15 min mashing at 150. I continued on with my Schmitz Decoction mash anyways which took about 1.5 hours total.

All this extra mash time may seem like a waste of time to some but for me it seems to give me some extra flavor and aroma I've been missing from my German lagers.

kaconga said:

Well my understanding is that a hydrometer/refractometer can only tell you how much sugars you have, not the make up of those sugars. So you can have two samples of 1.050 wort but one might be mostly dextrins and the other could be mostly glucose. This will drastically alter the FG of the sample and is one of the concerns with short mash times.

Click to expand...

That's what I said, only you said it better

Once you know you're getting 1.050 wort at every step, you've answered the "am I getting better efficiency with a longer mash?" question.

That's half the answer. Then once you ferment the 90-min batch, you'll know whether or not you get or even want the (potentially) higher attenuation, head retention, etc.

If not, go shorter next time, a little at a time, until you get the most efficiency and the right attenuation in the shortest time.

That's what I did, and I'm at 30 min. mashes now, with 84% efficiency, somewhat high attenuation, and identical head retention, storage, etc. from when I did longer BIAB mashes, or when I did traditional cooler mashing.

The last couple of batches I wanted to try even shorter mashes, but I'm at the point now where by the time I get the mill and everything cleaned up and weigh the hops and stuff, it's time to pull the bag.

TexasWine said:

Oh man. This is great! My favorite part...

"Haha this is why I always get a kick out of homebrew/nano setups where the guy's all "Check out my sweet HERMS!"

Click to expand...

hmmm . . . but they also talk about short mash rests, but long (up to 30 minute) vorlauf. When you recirculate with a HERMS or RIMS, isn't it pretty much the same as an extended vorlauf?

The one guy talks about a 20 minute dough-in while mixing, a short rest and then 15 minutes of vorlauf. Probably 45 minutes right there of time while conversion is taking place. Another one say "5 minute mash, 30 minute vorlauf, lauter within 90 minutes." 90 minutes!

Just saying that going by what the pros do to either support or condemn short mash times on a homebrew level doesn't make sense.