### Author Topic: Prepping a cooler  (Read 6700 times)

#### gmac

• Brewmaster General
• Posts: 2165
• London, Ontario
##### Re: Prepping a cooler
« Reply #15 on: April 07, 2011, 12:20:09 pm »
Thanks all.  I'm betting the problem is my procedure.  I'm adding the cellar temp grain to the "warmed" cooler and then the water.
Next time I'll put in all the water at 180 or 185 and then let it sit and cool down to strike temp and then add the grain.  I didn't think that there'd be a big difference because I'm stirring well and not getting dough balls but clearly I am wrong.

I'll also put a towel under it on the cement floor.

#### euge

• I must live here
• Posts: 8017
• Ego ceruisam ad bibere cervisiam
##### Re: Prepping a cooler
« Reply #16 on: April 07, 2011, 12:20:40 pm »
Quote
Calculating Your Thermal Mass with ProMash
contributed by the_stain

Q: What is the Thermal Mass of my mash tun, and how can I calculate it?
A: Thermal mass is the amount of heat your mash tun will absorb when you add the water. This can affect your calculations a bit when attempting to calculate your strike temperatures.

The default or "average" thermal mass of 0.30 will get you pretty close most of the time, but you can measure it yourself with the following procedure:

1. Go into ProMash and go into the Strike Temp calculator.
2. For Mash Tun Thermal Mass, Enter 0.
3. For Total Grain enter 0.00001 pounds. (It won't let you go any smaller - entering 0 will give you a division error.) This should make your water:grain ratio 120000:1.
4. For Total Water, enter 16.00 quarts.
5. For Desired Strike Temp, enter 170. (You can use any temperature but this will more accurately reflect actual mash temperatures.)
6. For Grain Temp, enter the current room temperature.
7. Heat 16 quarts (4 gallons) of water to 170 degrees and pour it quickly into the mash tun. Close the lid and seal it up, and let it sit for about 5 minutes.
8. Measure the temperature of the water in the mash tun.
9. Enter the temperature of the water in the mash tun in the "Desired Strike Temp" field in ProMash.
10. Now look at the "Initial Strike Water Temp Should Be" window. You will note that, with Thermal Mass set to 0, this number will be the same as the "Desired Strike Temp" field.
11. Now, in small (say 0.1 or smaller) increments, increase the Thermal Mass field until the "Initial Strike Water" field reads 170 (or whatever temperature you started with, if you didn't use 170 for some reason.).
12. Ta-da! Whatever the Thermal Mass field says is your mash tun's thermal mass!

This'll getcha closer to your strike and you won't have to preheat the tun. Theoretically. The temp of the tun matters as well. If you had it in the garage in cold weather or in the house where it's warm there will be a difference when you pour the water in.

Cover your tun with a sleeping bag or comforter. I've always had a mash temp drop. My efforts/hopes are to keep it stable for the first 30 minutes. Then not worry so much...
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#### tonyp

• Brewmaster
• Posts: 656
• If it ain't broke you aren't trying hard enough...
##### Re: Prepping a cooler
« Reply #17 on: April 07, 2011, 01:38:33 pm »
I have a good friend who's a homebrewer and a plastics guy by trade.  He assures me that all the coolers he knows of are HDPE.

great news, thanks guys, looks like i'l be going all-grain soon!
Live from the Jersey Shore!

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"I'll try being nicer if you'll try being smarter."

#### Will's Swill

• Brewer
• Posts: 359
• Secretly likes wine...
##### Re: Prepping a cooler
« Reply #18 on: April 09, 2011, 10:31:04 am »
Are y'all talking about temp drop from strike water to end of mash?  As opposed to stabilized temp with water and grist to end of mash?  I admit that I lose 10 - 20 degrees from HLT to stabilized temp, but I lose only about 1 - 2 degrees even over 90 minutes in my Rubbermaid cooler once I've thoroughly doughed-in and closed her up.  And I mash outside even when it's snowing and I routinely leave my cooler on the ground.  And I don't preheat at all.  I also monitor the temp continuously with an oven thermometer with the cord coming out from underneath the lid.

Just curious, because y'all seem to have a lot of heat loss.
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#### tubercle

• Senior Brewmaster
• Posts: 1639
• Sweet Caroline
##### Re: Prepping a cooler
« Reply #19 on: April 09, 2011, 02:39:45 pm »
Thanks all.  I'm betting the problem is my procedure.  I'm adding the cellar temp grain to the "warmed" cooler and then the water.
Next time I'll put in all the water at 180 or 185 and then let it sit and cool down to strike temp and then add the grain.  I didn't think that there'd be a big difference because I'm stirring well and not getting dough balls but clearly I am wrong.

I'll also put a towel under it on the cement floor.

That what i do and hit within 2 or 3 degrees every time. It take a while to learn your system. I can bet on having my water about 14f above mash temps. This pre-heats everything and you can get the temps down fairly quick with some stirring before adding grain.
Sweet Caroline where the Sun rises over the deep blue sea and sets somewhere beyond Tennessee

#### gmac

• Brewmaster General
• Posts: 2165
• London, Ontario
##### Re: Prepping a cooler
« Reply #20 on: April 14, 2011, 07:53:58 pm »
Just to bring some closer to my post, this time I added 20 quarts of 185 degree water to my cooler/mash tun.  Left it for 10 minutes and it was down to 171.  Added my grain (note to self - stir while adding next time...Holy grain balls!).
Had to add 2 quarts of cold water to bring it down to 156.  Also elevated the cooler off the floor.
After 1 hour, the mash was reading 154 so it only went down 2 degrees at most.  Clearly my problem was my procedure. Thanks everyone for the suggestions.

#### Hokerer

• I spend way too much time on the AHA forum
• Posts: 2654
• Manassas, VA
##### Re: Prepping a cooler
« Reply #21 on: April 14, 2011, 07:56:28 pm »
Glad to hear you figured it out.  Thanks for following up.

And yeah, pretty important to stir while adding grain to water
Joe