Cooler MLT heat absorption questions.

[Ridemywideglide]

I'm testing my 70qt MLT today so I can get an idea of how much heat it's going to steal starting from room temperature. Is there a set time I should wait? I've set the timer at 10min, poured in 8 gallons of 170* water, stirred and checked the temp. Digital read 168.5*..
Should I be checking every 10min for a half hour? or is 10min enough time to get the cooler heat soaked?

Also, where do I put this information in beersmith? I see a mash tun specific heat option, showing .3 cal/gram-deg C.. ???? More greek, I thought I ordered the english version..

Thanks

 

[FlyGuy]

I would guess that 10 min should be enough time for the temps to equilibrate. 20 mins would pretty much guarantee it, I suspect (but I don't have an MLT that big, so I am just estimating).

Regarding Beersmith, don't change the specific heat value for your mash tun. Keep it set to the default for a plastic tun at 0.300 irrelevant metric units. Instead, just make sure you enter in the mass/weight of the tun. That will get you close. To dial it in perfectly, you will need to tweak it a little with every batch until you are hitting your target temps bang on.

Best of luck!

 

[Ridemywideglide]

Ok thanks for the reply. I weighed my setup and it's 15lbs, but that didn't change the numbers in beersmith.

I think it will go ok but it's my first AG so I'm worried. BS says 163* with MLT and grain losses to get to 150* figuring ambient of both 70*. My MLT was 74 interior temp in the garage today, so I would assume the grain would be close to the same in the garage on brewday.

Also, batch sparge options are set at:

Batch sparge using batches that fill "50%" of mash tun volume.
Sparge using equal size batches
Drain mash tun before starting to batch sparge.

I know I'm not using 50% of my volume for my sparge... BS shows total sparge @ 3.27. Of which I should be using half for each of 2 sparges correct?


Forgot to mention, the MLT was down to 165.5* in 10min, and after an hour it was down to 160*.
I have a problem with the front wall being bowed out slightly allowing heat to escape and the lid to not seal properly. I've got a ratchet strap on it tonight bowing it in severly to see if it will reshape. I think I lost alot of heat because of this, but the first 10min reading should be pretty close if I can get it all sealed up tight.

 

[jds]

WideGlide:

One thing that I've found helps is preheating the tun. Tell Beersmith you don;t care what it thinks by unselecting the "adjust temp for equipment" check box. Now, Beersmith will calculate your strike water temperatures based only on the amount and temperature of your grain*.

Heat your strike water to 10 or so degrees over what Beersmith tells you, then charge your mash tun and let it sit for five to ten minutes, then check the temperature. If it's what you want, dough-in the grains. If it's still too high, stir for a few minutes with the lid off or adjust with SMALL amounts of cool water.

By doing this, you get the mash tun nicely heated up, you can still tweak the water temperature after charging the tun with water, and I find it's pretty easy to hit my temperatures this way.

*Grain temperature DOES matter. Take the grain's temperature just before you dough-in, and make sure you're still aiming for the correct strike water temperature.

 

[Evets]

Also, you could cut a piece of foam insulation to fit inside your mlt and sit right on top of the mash. This eliminates the head-space and keeps the heat in the mash.