Soon to be an AG brewer - question about mash tun

[OKCAg2002]

Do you guys "pre heat" your mash tun with boiling water before the mash in? Or simply use a room temp cooler? I've seen it done both ways. Is there a significant heat loss with the hot liquor if you don't?

Thanks guys! I'm sure I'll have a ton of questions. I hope to join the ranks next week after the holiday.

 

[GenIke]

I usually dont preheat mine since my brewing software adjusts for the temp of the mash tun. I just end up adding slightly warmer water at mash in and everything equalizes near my planed mash temp.

 

[Culbetron]

Ditto

 

[brew_ny]

I preheat mine it sits in a garage that is about 40 degrees with my grain

so a couple of gallons of boiling water to heat it up and it is good to go

S_M

 

[OKCAg2002]

I saw in BeerSmith you can check the box to account for the tun temp in the strike water. Is it pretty accurate?

 

[Setesh]

I never do either, I just use what BeerSmith tells me to and it always works out good.

 

[GenIke]

I saw in BeerSmith you can check the box to account for the tun temp in the strike water. Is it pretty accurate?

It's been accurate enough for me. My tun it stored in my wisconsin garage, so I usually bring it inside to warm up a bit and enter a mash tun temp of 68 or so. I have never tried using the adjust for temp with anything that was really cold.

 

[LandoLincoln]

Do you guys "pre heat" your mash tun with boiling water before the mash in? Or simply use a room temp cooler? I've seen it done both ways. Is there a significant heat loss with the hot liquor if you don't?

Thanks guys! I'm sure I'll have a ton of questions. I hope to join the ranks next week after the holiday.

We learned from our own equipment experiences that if we didn't pre-heat the mash tun, we lost an extra 2° F. We decided that just heating the liquor in the HLT two more degrees was easier than pre-heating the mash tun.

 

[brewkinger]

Pre heating is definitely the more thermodynamically correct way to do it.
If you (or BeerSmith) is calculating that X pounds of grain added to Y gallons of water at a specific temperature will equal out to a specific mash temperature then pre heating the mash tun will work out best for you.
FYI: I would not advise adding boiling water (or hotter than 180 degrees for that matter) into a plastic cooler. It will warp the plastic inside and more than likely screw the cooler up.

 

[MindenMan]

I still don't have a real mash/lauter tun. I currently use my 22 qt SS pot, as my mash tun, and a Zapap to lauter/sparge with. I hit my numbers dead on, so I can't justify buying another piece of gear.

 

[EmDubeu]

I usually dont preheat mine since my brewing software adjusts for the temp of the mash tun. I just end up adding slightly warmer water at mash in and everything equalizes near my planed mash temp.

Ditto

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[EmDubeu]

Why do you need to pre heat the mash tun? I heat my strike water in the mash tun, then when the water hits about 10 degrees above my target mash temp I dough in. Am I doing something wrong?

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[insanim8er]

I put my water in the tun at a slightly higher temp. Let it sit for a minute then add my grain... I generally come in a degree or two high, so once I'm done mashing the dough balls, I'm at temp.

 

[grathan]

I saw in BeerSmith you can check the box to account for the tun temp in the strike water. Is it pretty accurate?

I find it accurate to within 1 degree F even when I guess grain and tun temps.

 

[JonM]

I run some hot tap water from the laundry sink into the tun, mostly because I store gear in the the basement and it is really cold down there - like i have a lager fermenting in the ambient air type cold. Seems to work just fine.

 

[K5MOW]

My mash tun sits in the house at 70 degrees so I do not.

Roger

 

[GilSwillBasementBrews]

Why do you need to pre heat the mash tun? I heat my strike water in the mash tun, then when the water hits about 10 degrees above my target mash temp I dough in. Am I doing something wrong?

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Pre heating of the mash tun is just for those using coolers or some other vessel that is not direct fired.

 

[rycollier]

I usually preheat my cooler but if I happen to forget I know that I need 4-5 more deg for the mash water depending on the cooler's ambient temp. The most important thing is to know the difference so if you forget you don't end up trying to fix your mash temp with more boiling water. Having to thin your mash with boiling water usually makes lighter beer and if you still end up with low mash temp you get even lighter and possibly over attenuated beer.

 

[Yooper]

I saw in BeerSmith you can check the box to account for the tun temp in the strike water. Is it pretty accurate?

Yes, but it doesn't hold the temperature as well if you don't preheat the cooler MLT. I will lose about 6 degrees in an hour with a non-preheated cooler vs one that is preheated. In a preheated cooler, I lose about 1 degree over the course of an hour.

Why do you need to pre heat the mash tun? I heat my strike water in the mash tun, then when the water hits about 10 degrees above my target mash temp I dough in. Am I doing something wrong?

This IS preheating. You're adding hotter water to the MLT, and letting the cooler absorb the excess heat. Then mashing in when the water cools to strike temperature.


It really depends on where you store your MLT, but as an experiment try adding 1 gallon of hot (NOT BOILING!) water to it. Make it 180 degrees at the highest, to avoid warping and cracking. Stir up the water, and take temperature readings. It will drop 10 degrees or more, really fast. Then, it will hold the temperature after that. That's what you want when you mash as well.

I add 180 degree water to the MLT, and give it about 15 minutes to cool to strike temperatures. By then, the MLT is nicely preheated and then when I mash in, it holds the heat quite well.

Also, the bigger the mash is, the more stable the temperature, especially in a big cooler. A 7 pound grainbill will lose temperature more quickly than a 20 pound grainbill in the same sized cooler. Preheating really helps with the smaller grainbills.

 

[insanim8er]

Yes, but it doesn't hold the temperature as well if you don't preheat the cooler MLT. I will lose about 6 degrees in an hour with a non-preheated cooler vs one that is preheated. In a preheated cooler, I lose about 1 degree over the course of an hour.

I use a 10 gallon round. And this is pretty much my experience too. My temps weren't as accurate with out pre heating. Now I lose no more than 1 degree, so that's why I preheat.

In addition to a much more stable mash, I also find it easier to hit temp since it's easier to lower the water temp than it is to get it back up.

Preheating and lowering the temp from the cooler makes it so I don't have to worry about different ambient temps (I brew outside), different grain temps, heat loss from the hose during transfer, or prolonged stirring times to mix the mash... Etc.

 

[Jamie_K]

I agree. We get more consistant results by preheating our Coleman Extreme mash tun.

 

[Ortega917]

Usually in the winter time ill pre heat. But in the summer time I dont its been working out so far.

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[jakeasaur]

I put my water in the tun at a slightly higher temp. Let it sit for a minute then add my grain... I generally come in a degree or two high, so once I'm done mashing the dough balls, I'm at temp.

This is what I do also

 

[elkshadow]

I guess I'm with Yooper that putting water in that is hotter is pre-heating even though everybody is saying, "I don't pre-heat I just put hotter water in and let it cool to dough-in temp."

Probably semantics at this point.

I lose 3 degrees when I pour hot water into my room temp tun. Then I lose another ten when I add the grain. So I just make my water 13 degrees hotter than I intend to mash. I get how using water that is 3 degrees higher so it stabilizes is pre-heating the tun although I never thought of it that way or called it that.

TL;DR It will take you a couple times to figure out how to get the correct strike temp.

 

[Culbetron]

Pre heating is definitely the more thermodynamically correct way to do it.

If the laws of thermodynamics just started getting proscriptive instead of simply descriptive they are going to be getting really annoying really quickly.

 

[SliverXZennon]

Just did all grain Saturday night in the garage, 38 degrees outside and we heated the strike to 164, closed the lid on MLT and then add grain after about 10 minutes. Perfect 152 degrees dough in and didn't lose one degree in 60 minutes. I wouldn't get too caught up in this temp issue. Do it how you can to get and hold your temp and set/forget.