Pre-heating a mash tun..

Do you pre-heat your mash tun before adding grain and strike water? If so, what kind of MLT do you have, and how do you pre-heat it?

I have a 48qt Igloo Cube, and I pre-heat it by adding the strike water at around 180F (if it's cold in the garage). I'll let it sit in the tun for about 10 mins, and it usually settles around 169F to dough in for 154F mash.

I just brewed a 1 gallon batch in a 2 gallon cooler mash tun that I put together recently. I preheated it with 160F water for about 15 minutes. I think preheating is probably more important on small batches like this since there is less water/thermal mass to heat up the cooler/valve/stainless braid.

Dump in hot water let it sit a few minuets. Dump it out, proceed as usual.

PoppinCaps said:

I have a 48qt Igloo Cube, and I pre-heat it by adding the strike water at around 180F (if it's cold in the garage). I'll let it sit in the tun for about 10 mins, and it usually settles around 169F to dough in for 154F mash.

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I like the sounds of this.. I plan on making a 48qt Cube tun as well!

I never understood the point of using separate water to preheat. I just heat the strike water up like 10-15 deg more and let it sit until it cools down to actual strike temp.

29thfloor said:

I never understood the point of using separate water to preheat. I just heat the strike water up like 10-15 deg more and let it sit until it cools down to actual strike temp.

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Yeah, I was hoping to avoid using seperate water, too. I just wasn't sure how much the temp would drop after putting it in a room temp cooler.

29thfloor said:

I never understood the point of using separate water to preheat. I just heat the strike water up like 10-15 deg more and let it sit until it cools down to actual strike temp.

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I feel heating the water 10-15 degrees more is too much is like a shot it the dark.

My cooler only loses 1-2 degrees in an hour so I don't want to wait until it hits the proper temperature.

I preheat with hot water, dump it out and heat the strike water to the calculated temperature. I have missed at the maximum by 4 degrees high, once.

It looks like I need to experiment with some hot water to find the "sweet mark" .. I'll try 10 degrees higher first and see how it does. I don't want to wait forever either.

I'm thinking I could enter the temp of the plastic into a calculator just like you would the temp of grain to see what the strike water would be.

If you look into the Igloo Cube, here's the data that I can repeat almost to the degree by now (if I don't change anything drastically):

Mash tun temp: 60F
Grain temp: 60F
Mash water: 4 gal
Grain amount: 10-11lb
Strike water: 180F
Dough-in temp: 169F
Mash Temp: 154F

PoppinCaps said:

If you look into the Igloo Cube, here's the data that I can repeat almost to the degree by now (if I don't change anything drastically):

Mash tun temp: 60F
Grain temp: 60F
Mash water: 4 gal
Grain amount: 10-11lb
Strike water: 180F
Dough-in temp: 169F
Mash Temp: 154F

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This works for me! Thanks!

kh54s10 said:

I feel heating the water 10-15 degrees more is too much is like a shot it the dark.

My cooler only loses 1-2 degrees in an hour so I don't want to wait until it hits the proper temperature.

I preheat with hot water, dump it out and heat the strike water to the calculated temperature. I have missed at the maximum by 4 degrees high, once.

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It probably is a shot in the dark but it's worked ok for me so far. I'm sure sometime it won't work out and I'll try the separate water method. I guess if you reuse the preheat water as your sparge water it's not a big deal.

29thfloor said:

I never understood the point of using separate water to preheat. I just heat the strike water up like 10-15 deg more and let it sit until it cools down to actual strike temp.

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This what I do. Shot in the dark or not it works and is simple.

I heat and recirculate through the HLT and MT with gas and element, while I am grinding grain, with my RIMS and PID. Preheating. Then recirculate throughout the mash with the same.

I have a 10 gallon round Home Depot water cooler. I use boiling water to heat it up for about 10 minutes, then just dump it back into the pot it came from. Though, I've only finished a total of three AG batches. I had a stuck sparge during my third batch this weekend. I was adding mash water at about 165 and everything seemed to be going well because the at about 70 minutes, I'd only lost about 4 degrees. When I took the lid off to sparge, the temperature dropped much quicker and at flow stop the mash lost another 5-6 degrees within minutes. I can't imagine that my preheating is wrong, but my house was at 64F, maybe that was it. I just kept increasing the temperature of each quart of sparge water and it finally started again. I can't imagine that preheating helps much beyond the first few minutes, but I am thinking that keeping the damned lid on helps a bit!

Thanks,
Isaac

I also use an igloo cube and I love it. I usually boil a gallon of water throw it in the tun and put the lid on. Shake it up and let it set. I usually have 2 burners going so I can heat my strike water at the same time as the tun heating water. I dump the heating water, add my grain and then dough in a gallon of water at a time. I think it was Palmer that was talking about you do not want to add grain to your strike water as you are likely to shock the enzymes with the heat. If you add water to your grains the temp of the water is being dissipated faster.

Beersmith has a field for MLT and grain temp.
It uses those to help compute the strike temp, and for me they have been dead on.

It's pretty important for me, as my MLT is a sanke keg, which can soak up a lot of the heat from the strike when it's cold.

5 gallon round igloo. Throw some hot water in, toss in a heat stick, bring it up exactly to the temp my software tells me where it needs to be for my room temperature and mash temperature. Easy peasy. Love my heat stick.

I used to but not anymore, saw no gain other than running "rinse water" through system. I used to add the water to the grain in the cooler MLT, these days I'm adding the water and doughing in with the grain... this way I know that the water is exactly at strike temp and can adjust prior to adding grain (if for instance the MLT absorbed too much heat -hasn't happened yet though). Try it, if you don't see a benefit in your system, save the effort for something that affects the beer!

Cheers!

Nohup said:

Beersmith has a field for MLT and grain temp.
It uses those to help compute the strike temp, and for me they have been dead on..

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^This. I am using beersmith for the first time and am tickled pink that it can compensate for not only different temperatures, but different materials and their conductivity.

I fill about 2 gallons of my hottest tap water - about 135 degrees. Then I add boiling water from my tea kettle until I hit my mash temp and seal it up. When I'm ready I dump that water and add my strike water. Sounds silly since the water is already in there but it preheats well and then holds a steady temp. When I'd tried preheating with the strike water I was always 2-4 degrees off. Works for many others though but my method isn't any trouble for me and it's working well.

Rev.

Same here as bmud and Nohup, I'm a Beersmith user and I simply configured an equipment profile and use the "Adjust Temp For Equipment" option.

I run with a 48qt rectangle Igloo and a S/S toilet braid manifold. When I think of it (and I don't usually) I try to remember to edit my mash profile for that specific recipe with today's actual outdoor temperature, to improve my accuracy.

On my brew yesterday, I missed my mash temp by only 2*F due mostly to the cold weather outside. It takes me *just* long enough to stir the grain together while I'm mashing in, that the last couple of quarts of strike water in the kettle cool off more than desired by the time I dump them in.

I have an electric HLT that I'll use once I get my indoor brewing station setup, then missing my mash will be a thing of the past, thanks to the digital temperature controls.

I posted a similar question a few weeks ago. Basically what I was finding is that most brewing software does not accurately calculate strike temperature due to mash tun temp and heat absorption. If I had followed the software I would have missed my mash temp big time. I was given the advice to simply add the water at 180 degrees and let it slowly cool to the desired strike temp. This worked like a charm and I will continue to use this method. I could not believe how much heat my cooler absorbed within just a few short minutes.

brew2enjoy said:

I posted a similar question a few weeks ago. Basically what I was finding is that most brewing software does not accurately calculate strike temperature due to mash tun temp and heat absorption. If I had followed the software I would have missed my mash temp big time. I was given the advice to simply add the water at 180 degrees and let it slowly cool to the desired strike temp. This worked like a charm and I will continue to use this method. I could not believe how much heat my cooler absorbed within just a few short minutes.

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I read a post that may have been from that thread saying to preheat w 180 deg water, stir a bit to get it to dough in temp, dough in a little high, then stir the mash to drop to mash temp. I've done two batches this way and have increased my efficiency by 10%. My first few batches were about 65%, this method put me up to 75. I think my cooler loses more heat than it should. It may have a spot that's missing insulation. But still that works well for me.

This is all a bunch of great food for thought! I'm currently doing AG with BIAB, but I plan on moving to a mash tun soon, and I want to be well educated before giving it a try. I have a SS sanke keg that I could turn into a MLT. I like the sounds of the Igloo cube, though. I'm not sure which one I will use yet.. I'm guessing if I make one out of the keg it can double as a kettle.. Choices, choices!

Nohup said:

Beersmith has a field for MLT and grain temp.
It uses those to help compute the strike temp, and for me they have been dead on.

It's pretty important for me, as my MLT is a sanke keg, which can soak up a lot of the heat from the strike when it's cold.

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Same here. I preheat my tun (10 gallon rubbermaid) and grains by simply bringing them into the house the night before I brew. I can then use 70 degrees for my beersmith calculations. I still heat my strike water a few degrees warmer than what beersmith calls for. Much easier to stir out a few degrees of heat than try and add boiling water to bring the temp up.

Yeah, Beersmith has always been about 4 degrees off for me given all of the specs I can input. So much relies on your exact equipment, and software gives you a pretty good place to start. Brew often and write everything down.

I took the closest pre-configured option within BeerSmith, and then spent some time customizing it to match my actual set of equipment.

29thfloor said:

It probably is a shot in the dark but it's worked ok for me so far. I'm sure sometime it won't work out and I'll try the separate water method. I guess if you reuse the preheat water as your sparge water it's not a big deal.

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Remember the engineers credo: If it's stupid but it works, it isn't stupid.

I preheat my cooler mashtun by going 8-10 degrees past my strike temp. If after 15 minutes I am too high I simply open and stir. It does not take long to get it to drop the few degrees I may be off. Simple and efficient for me.

Stauffbier said:

This is all a bunch of great food for thought! I'm currently doing AG with BIAB, but I plan on moving to a mash tun soon, and I want to be well educated before giving it a try. I have a SS sanke keg that I could turn into a MLT. I like the sounds of the Igloo cube, though. I'm not sure which one I will use yet.. I'm guessing if I make one out of the keg it can double as a kettle.. Choices, choices!

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Well you can fit a 10 gallon batch of grain in an igloo cube no prob, and then boil it in that sanke. Sounds like a plan to me. Now I'm jealous.

mobilecabinworks said:

Well you can fit a 10 gallon batch of grain in an igloo cube no prob, and then boil it in that sanke. Sounds like a plan to me. Now I'm jealous.

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I started my keggle build yesterday. Here's what it looks like. I just need to get valves and polish it up...
[/IMG]

Now I'm also going to shop around for an igloo cube..

I have a Coleman Xtreme 52 qt MLT. I bring about a gallon of water to a boil on the stove then throw in it the MLT while the strike water is coming to temp. Drain the water right before I put my strike water in. I then use Beersmith to tell me my strike temps, and it hits my mash temp dead on every time! Easy day!

I use a converted igloo water cooler and just fill it up with 150 degree tap water while I'm heating my strike water. Works for me.

I came here because i"m having major issues with my mash temps. Not my strike temps, mind you. [As others here do, I heat my mash water 10-12 degrees beyond my target strike temp and let the cooler preheat about 10 minutes. Then I wait and/or stir until the water reaches strike temp, and I dough in.]

I use a 52 qt rectangular Coleman XTREME, and I'm losing 6-7 degrees over a 60 minute mash! WHY?!!?

Er... I mean, why? Please?

Judochop said:

I came here because i"m having major issues with my mash temps. Not my strike temps, mind you. [As others here do, I heat my mash water 10-12 degrees beyond my target strike temp and let the cooler preheat about 10 minutes. Then I wait and/or stir until the water reaches strike temp, and I dough in.]

I use a 52 qt rectangular Coleman XTREME, and I'm losing 6-7 degrees over a 60 minute mash! WHY?!!?

Er... I mean, why? Please?

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I'd try preheating for longer. Fill the cooler with tap water as hot as you can get it and let it sit for 1/2 hour or so. If you're losing that much heat I'd also wrap it in a sleeping bag or two.

I do. I have a cooler. I usually just turn on the hot water tap and fill it with a couple gallons of hot tap water, then seal it up and let it sit til I'm about ready to mash in.

lizardeye said:

I'd try preheating for longer. Fill the cooler with tap water as hot as you can get it and let it sit for 1/2 hour or so. If you're losing that much heat I'd also wrap it in a sleeping bag or two.

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I thought I was getting the cream of the crop with this coleman xtreme. I didn't think it'd take that long.

Calling all Xtreme users, for how long do you preheat?

One thing i noticed with my cooler, the part of the lid with the handle indentation didnt seal too well so i put a large heavy object the length of my cooler on top of the lid to help seal. I also throw a sleep bag doubled up over the cooler. It now holds temps great.

richbrew99 said:

One thing i noticed with my cooler, the part of the lid with the handle indentation didnt seal too well so i put a large heavy object the length of my cooler on top of the lid to help seal. I also throw a sleep bag doubled up over the cooler. It now holds temps great.

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I feel pretty good about my seal. It takes a good hearty push just to close.

How long do you preheat?

I will try some external insulation next time, but I feel like 6-7 degrees over 60 minutes is a pretty big loss. Hard to imagine a sleeping bag will make the difference.