Problems with Mash Temps

I seem to have some trouble lately hitting my mash temps. The first batches using Brewsmith went flawlessly, now all of a sudden, I don't know what's going on...


I have a Coleman Xtreme 50 quart(?) cooler. Copper manifold. Today I preheated the MLT to 170 degrees, once steady, I added 22 pounds of grain.

Assuming 22 quarts of water, what temperature would you think I should heat the water to? Anybody care to throw in some thoughts...? Techniques? Tricks?

I'm getting pretty frustrated by this...

I know this may not be helpful in the short run, but frustration like yours was why I went to a direct heat mash system... Where I live, the ambient temps vary so much, I could never rely on a formula, and I wasn't into temperature controlled storage for all my grain and stuff.

And for years, I didn't have a mash-lauter tun... I mashed in a cheap ass 40 quart stainless pot I bought at an army/navy store in Reno for thirty bucks. Then, after mash out, I dumped the whole lot into the two-bucket thingy for the sparge...

Anyway, something to consider... cheers, -p

I have had good results using the Mash Calc linked here. Its always easier to cool the mash with ice cubes than to heat it with additional water so error on the high side.

http://www.rackers.org/calcs.shtml

Update. Check out Beerific's recent thread. Those guys are right about the limitations in terms of larger batches, but I found the system satisfactory for 10- 12 lbs of grain. -p

Mash temp problems? Really dude?

Didn't you just write this today:

Toot said:

Sure, maybe you are using bad temps, unable to hold a steady mash temp, losing heat, blah blah blah... but let's be realistic, anybody with the intelligence to build an MLT, or the intelligence to hold a job that gives them the money to buy an MLT, has the intelligence to maintain a mash temp.

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https://www.homebrewtalk.com/showthread.php?p=288639#post288639

Sorry man -- had to put in a bit of a dig there. Couldn't resist!

You never said if your mash temps are too high or too low and by how much. 170' should be about right to get you in the low 150s.

Is 22 lbs for a 10 gal batch? Is that the same grain bill and volume you when things were going right? If it's larger, I'm wondering if that could have something to do with it - different thermal mass.

Also, with that much grist you really have to make sure that you mix it very well, probably even more so with a thicker mash like you've got. If not, you'll have hot and cold spots. Are you getting consistent temps in different places in the mash tun?

Just some ideas.

Lil' Sparky said:

You never said if your mash temps are too high or too low and by how much. 170' should be about right to get you in the low 150s.

Is 22 lbs for a 10 gal batch? Is that the same grain bill and volume you when things were going right? If it's larger, I'm wondering if that could have something to do with it - different thermal mass.

Also, with that much grist you really have to make sure that you mix it very well, probably even more so with a thicker mash like you've got. If not, you'll have hot and cold spots. Are you getting consistent temps in different places in the mash tun?

Just some ideas.

Click to expand...

It was for a 5 gallon batch.

I mixed reasonably well, stirring maybe 8-10 times around.

And no, this is about twice as much grain as I'm used to mashing...

A lot depends on how much water you used. With 22 pounds of grain you will need at least 5 1/2 to 7 gallons of water. ProMash says to get 152 degrees with 6 gallons of water your dough in temp should be 167 degrees.
If you are using less water you will need to raise the temp and lower it for more water.

FlyGuy said:

Mash temp problems? Really dude?

Didn't you just write this today:

Sorry man -- had to put in a bit of a dig there. Couldn't resist!

Click to expand...

An intelligent person also asks questions so as to not repeat the same mistake and assesses the outcomes he encounters until he reaches perfection.

If I wanted to make a 1.060 stout, I'm sure my mash temp would've been find. I'm a little more picky though, so I dumped the entire batch down the drain.

RichBrewer said:

A lot depends on how much water you used. With 22 pounds of grain you will need at least 5 1/2 to 7 gallons of water. ProMash says to get 152 degrees with 6 gallons of water your dough in temp should be 167 degrees.
If you are using less water you will need to raise the temp and lower it for more water.

Click to expand...

What grain temp are you using?

I'm trying to tweak the setting in Brewsmith here to get something that comports with everyone else's reality.

Toot said:

An intelligent person also asks questions so as to not repeat the same mistake and assesses the outcomes he encounters until he reaches perfection.

Click to expand...

He also knows that 'perfection' is unatainable

Toot said:

If I wanted to make a 1.060 stout, I'm sure my mash temp would've been find. I'm a little more picky though, so I dumped the entire batch down the drain.

Click to expand...

What a waste.

Do you have Promash or Beersmith? I always use the latter to calculate this info. I plug in what kind of water-to-grain ratio I'm looking for, you use room temp for the grain temperature, and I know from my experience that I need to adjust its results upward by about two degrees for my equipment/procedures. I don't have the program installed here at work, or I'd do some math for you.

the_bird said:

Do you have Promash or Beersmith? I always use the latter to calculate this info. I plug in what kind of water-to-grain ratio I'm looking for, you use room temp for the grain temperature, and I know from my experience that I need to adjust its results upward by about two degrees for my equipment/procedures. I don't have the program installed here at work, or I'd do some math for you.

Click to expand...

I use Beersmith. And it works fine when I'm mashing 10 lbs or so of grain. When I double that, well, I dunno, my mash temps are low. About 10 degrees low.

I put 18 quarts of 172 degree water into 22 lbs of 68 degree grain in a 170 degree MLT and my mash temp after 30 minutes (only opening it once to stir) was 142.

D2T said:

He also knows that 'perfection' is unatainable

Click to expand...

Touch your nose.

If you did it, then it was perfect. You fulfilled all the terms of the objective. It doesn't get more perfect than that.

What a waste.

Click to expand...

I am interested in creating recipes far more than in drinking. If I wanted something to just drink, I would head to the corner liquor store. Therefore, if my recipe doesn't get where it's supposed to go, what's the point of a bastard batch?

Sure I can bottle it and give it to friends and they'll appreciate it, but it ties up another carboy. I have very little space and as a result, I won't be able to brew something I like for another three weeks.

Woot! Toot! Thats a good one.....I'll have to remember that perfection thing....but wasting that wort.........SACRILEGE! You should punish yourself by drinking it and not enjoying while reminding yourself that you screwed up and have to improve it next time......OR just send it to me and I'll tell you in a PM.....

I bought beer tools pro and it looks like it has a really good mash temp calc as long as you figure out how to use it AND calibrate it based on your equipment. I haven't done so yet. It asks you to fill your MLT with hot water, then measure the temp at 5 minutes and 60 minutes. This will tell the software how much heat the MLT initially absorbs and how much it loses over the mash time. Pretty cool.

One thing to consider is the bigger your grain bill, the more impact its own temp will have on the equalized mash temp. On big brew day, I put my temp probe down into my bucket filled with 20lbs of grist and it read 53F. The air was 75 at the time, but I left the bucket in the back of my pickup overnight. Bottom line, measure your grain temp, don't guess.

Assuming you calibrate so the software or whatever calc you use knows how much heat your MLT will steal, you can mash in perfectly. However, most easy calculators only consider grain temp, amount and ratio. For this to work, you need to strike with water much hotter, let the MLT absorb the heat, then wait until it hits your target strike. Example, I'll heat the water to 185, dump into the cooler, cover for 5 minutes to heat everything, then open it and measure temp. If it's the correct strike temp for the grain conditions, I dough in. If it's high, i'll stir until it cools to that temp. If it's a little low, remove a gallon of water and heat it.

I'm leaning towards calibrating BTP correctly to see if it solves all my problems.

Time to take up steam mashing...

You guys push that steam mashing like it's a %&$#@ religion ;-)

I like the idea but I'm not going there unless I prove to myself that it's impossible to hit and hold a single mash temp or I decide I want to step mash, whichever comes first. Then again, I might get another 1/2bbl and just direct fire that mutha.

Are you taking a temp reading for your grains? Stick a pocket therm down into your bag of grains and wait 10 minutes. Make sure you use this temp when you use the calculator to figure your strike temp. If the grain is cool, the added mass of the grains is going to drop your temp more. Promash has a good strike calculator and I'm almost right on the money with my temps.

Yeah I think part of the problem is that Brewsmith's mash calculator sucks. Grrr... what a disappointment.

It asks for the weight of the grain and the weight of the mashtun. I ballparked the weight, but I should still be closer than 10-15 degrees.

Perhaps the problem... and experts PLEASE chime in here... is that the cooler I have (good for maintaining cold temps over 5 days) is too good. That is, it absorbs heat so slowly that my initial mash temps stay elevated too long and then slowly start to regulate over the course of 40 minutes, as opposed to a cheaper cooler which reaches equilibrium temp (between the grains and the cooler) much more quickly.

Any thoughts on this theory?

You guys push that steam mashing like it's a %&$#@ religion ;-)

Click to expand...

Sorry. Just trying to make people aware.

Flyguy and I met a few nights ago. We traded a few beers and shot the brewing breeze. He made a statement that really struck a cord with me. "Its all about controlling mash temps." I wholeheartedly agree. I find it very hard to believe that one can make outstanding beers without some sort of means to control the mash temps.

Getting the strike temp right is just one part of that. What about holding the temp for an hour ? Sure, the coolers don't lose much heat, but they still lose some.

Flyguy made an interesting observation... he said he wondered how many people having efficiency issues were really hitting their temps smack on. Just because the center of the mash is at 152F doesn't mean the whole mash is at 152F.

Toot said:

Yeah I think part of the problem is that Brewsmith's mash calculator sucks. Grrr... what a disappointment.

It asks for the weight of the grain and the weight of the mashtun. I ballparked the weight, but I should still be closer than 10-15 degrees.

Perhaps the problem... and experts PLEASE chime in here... is that the cooler I have (good for maintaining cold temps over 5 days) is too good. That is, it absorbs heat so slowly that my initial mash temps stay elevated too long and then slowly start to regulate over the course of 40 minutes, as opposed to a cheaper cooler which reaches equilibrium temp (between the grains and the cooler) much more quickly.

Any thoughts on this theory?

Click to expand...

I can't speak to your issue with huge grain bills, but other than the simple "add two degrees" adjustment I make, Beersmith's been great for me. When I'm doing a single infusion, I've been hitting dead-on - within a single degree, more often than not, not missing at all. I have a 36-quart Coleman Xtreme that I preheat as well, and these beers are generally 11lb - 13lb total grain.

I have a 10 gallon Gott igloo cooler. What I've been doing is preheating with hotter water (in the 172-175 degree range) and swishing it around and closing it up while I get the grain ready. I drain some out (but not all) and leave the lid off. When the water in the MLT is at my strike temp, I start adding the grain and the rest of the mash water at the right strike temp. I keep an eye on the temp as I'm adding, too, so I can go hotter or cooler if needed but haven't had to adjust it yet.

I think this does two things- it preheats my MLT and for a longer period of time, so it hits that "equilibrium" you've talked about. And it means that my wimpy arms don't have to lift as much hot water at one time. When/if I ever have a hot liquor tun, I'll change that method.

Toot said:

Yeah I think part of the problem is that Brewsmith's mash calculator sucks. Grrr... what a disappointment.

Click to expand...

I think you're wrong here. I bet the calculator is VERY close to calculations in other software.

Using Beersmith, I plugged in your numbers:
22 lbs of grain
4.5 gal strike volume
target temp 153' (guess)
initial grain temp 70' (if you're pulling them out of the fridge, they'll be lower)

It gave me a strike temp of 178'. That's probably why you ended up so low.

Changing your grain/water ratio to 1lb/qt puts the strike temp at 173'. This ratio w/ a strike temp of 170' would've gotten you to 150'.

It's not software. Just keep at it and you'll become more familiar w/ your system. Then it's smooth sailing.

Yooper Chick said:

And it means that my wimpy arms don't have to lift as much hot water at one time. When/if I ever have a hot liquor tun, I'll change that method.

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Time to get you one of these Yooper Chick! No more lifting, except getting you grains into the MLT.

The calcs can be done manually if you know a bit out thermodynamics.

Or you could use the strike temp calculator here. http://www.rackers.org/calcs.shtml

Toot said:

Touch your nose.

If you did it, then it was perfect. You fulfilled all the terms of the objective. It doesn't get more perfect than that.

Click to expand...

I did it, but in the end I think I could've done it faster and with more energy. Ah well, maybe next time.

Toot said:

I am interested in creating recipes far more than in drinking. If I wanted something to just drink, I would head to the corner liquor store. Therefore, if my recipe doesn't get where it's supposed to go, what's the point of a bastard batch?

Sure I can bottle it and give it to friends and they'll appreciate it, but it ties up another carboy. I have very little space and as a result, I won't be able to brew something I like for another three weeks.

Click to expand...

Some of the greatest discoveries were made by accident. But it's your beer, so kudos to you!

Thanks for the inputs. For you brewsmith users, what do you use for the mass of your tun? Do you use the actual weight?


I think I'm going to make a remote temperature probe of sorts... it might make things easier... especially now that I'm paranoid as all heck...

And yes, I'll even look into steam mashing, though I am loathe to purchase new equipment at this time...

Lil' Sparky said:

Time to get you one of these Yooper Chick! No more lifting, except getting you grains into the MLT.

Click to expand...

Sparky brags but has no recipes!

I like the setup though, it could be better and you could help
teach others!

Keggels are great I hear! I'm using a stainless steel kettle.

-- Trev

Toot said:

Thanks for the inputs. For you brewsmith users, what do you use for the mass of your tun? Do you use the actual weight?
..

Click to expand...

I use Beersmith and one of the options under equipment is 10 gallon Igloo cooler and 7.5 quart turkey fryer- so I just use that. So I never had to do any adjustments with it at all. It seems pretty accurate with strike temps.

I do NEED one of those three tier systems! That's awesome.

trev said:

Sparky brags but has no recipes!

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You can't blame me for bragging a little can you? Are you talking about how some people have recipes in their drop-down under their name? I've looked, but never saw how to add recipes. How do you get them in there?

BTW - I didn't see any for you, either.

trev said:

I like the setup though, it could be better and you could help
teach others!

Click to expand...

Of course it could be better. There's always some room for improvement. Look at how BrewPastor is always tinkering to make his already awesome brewery better. Next on my list is a pump, and maybe a water filter setup. With the pump, I may go to a HERMS setup, but I'm not in a huge rush on that.

I have answered a lot of questions from several other brewers and physically helped at least one other brewer build his. Did you have something else in mind about teaching others? I'm not an expert builder like some guys on here. I just hacked it together really. That was my first time welding and I used a bunch of scrap steel.

Got any suggestions for improvement or questions about it?

I had trouble hitting my targets for a long time, but I eventually narrowed it down.

This might sound a little odd to people accustomed to working with one measurement system or another, but I use one litre of water per pound, (not that there is a lot of different) then adjust only the strike temperature, never the amount of water.

My mash tun is no more than a plastic grape juice bucket with a spigot and a false bottom. With some towels over the lid, it will hold temperature for more than an hour.

I preheat the tun with hot water from the tap to just warm it up. by looking at my records, I worked out that my temperature loss is 9c.

(I had assumed that it was only 2c, but that was because of previous experience with a considerably thicker plastic bucket??)

I continually boosted my strike temperature until I was hitting the target. So for example the last batch I brewed I wanted to start at 62c so I heated my strike water to 71c

A bit stone aged, but it worked.

Saul,your encouragement to use a consistent amount of strike water per pound of grain is indeed sage advice. I should probably stop messing around with varying thicknesses of mash for awhile.


By the way, is it possible to have a mash that is too thick? I tried using less than a quart per pound of water and assumed that since the the grain was all under the water, that it was fine. Is there a reason you have to water down the mash any further than that?

By the way, is it possible to have a mash that is too thick? I tried using less than a quart per pound of water and assumed that since the the grain was all under the water, that it was fine. Is there a reason you have to water down the mash any further than that?

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A couple reasons -that I know of- I find that for a single infusion just enough water to fill the space between grains is fine. Any less and the grain bed wont retain heat as there is actualy a dropping water table forming. You might be able to see water at the top of the mash but air pockets will be forming deeper down.

The mash should also be thin enough to stir. (and take this with a grain of salt as I don't use a heated mash tun) One spot in the grain bed will be hotter than another, as the heat is convecting over time.

For example I've measured 61c at the top and 59c at the bottom. Stirring equalises the opportunity for enzymes to come in contact with starch at there preferred temperature. Stirling also cools the mash though, but it's better IMO to sacrifice a little heat in one spot to get another spot at least into range.

If your pulling a step the mash should be a little thinner in order to conduct the increase of heat through the grain.

If your pulling a decoction, same issue, but for a different reason. I draw grain out from the bottom, taking as little water as possible. If you take to much water the grain bed will drop below it's currant temperature, so if you have already calculated your boiling fraction you will fall short of your target. Also when you add back, you need it to be moist enough to get the non denatured enzymes from the unboiled grain, into the boiled grain, and get the heat from the boiled grain into the unboiled grain. (with a good stirring)

I simply add half a litre to a litre of water to the decoction it's self rather than use water from the mash tun.

This is all highly suspect advice though as I'm pulling decoctions to simulate a 2 step infusion. Weather or not this is a good idea, I'm unsure of, but the temperature changes have been dependable of late.

Also in a thinner mash the enzymes convert slower but more fully to provide a more attenuable wort.

Lil' Sparky said:

You can't blame me for bragging a little can you? Are you talking about how some people have recipes in their drop-down under their name? I've looked, but never saw how to add recipes. How do you get them in there?

BTW - I didn't see any for you, either.



Of course it could be better. There's always some room for improvement. Look at how BrewPastor is always tinkering to make his already awesome brewery better. Next on my list is a pump, and maybe a water filter setup. With the pump, I may go to a HERMS setup, but I'm not in a huge rush on that.

I have answered a lot of questions from several other brewers and physically helped at least one other brewer build his. Did you have something else in mind about teaching others? I'm not an expert builder like some guys on here. I just hacked it together really. That was my first time welding and I used a bunch of scrap steel.

Got any suggestions for improvement or questions about it?

Click to expand...

No suggestions for improvement. I'm a newb! I just like your setup and am looking for a better setup. I'm doing batch sparges in a bucket setup. I got a way low volume my last AG (only my second).

I know, I still need to post my Hefe and Fat Tire clone recipe.

Just looking for more advice and tips that is all.

Good brewing friend!

-- Trev

Ah, I figured out how to add recipes. You have to add them to the recipe db and they automatically show up - cool. I've added one. I'll add some more when I get the time.