Pre-Heating Mash Tun?

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RoKozak

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During my first AG brew this past weekend, I hit my target temp of 154 degrees during the initial part of my mash. Over the 60 minutes, it dropped from 154 to 149.

To pre-heat, I put in a couple of gallons of 180 degree water into my MLT with the lid on for about 5-10 minutes. I dumped the water out when it was time to add the strike water.

To get to 154, I heated my strike water to 173 degrees, added the strike water then the grains. It held at 154 for 20 minutes and then dropped over the 60 min time to 149. The recipe called for 13.75 qts for the 11 lbs of grain.

My question: Where did I go wrong to keep the temp consistent throughout the mash?
(My MLT is a 10 gallon rubbermaid cooler.)
 
During my first AG brew this past weekend, I hit my target temp of 154 degrees during the initial part of my mash. Over the 60 minutes, it dropped from 154 to 149.

To pre-heat, I put in a couple of gallons of 180 degree water into my MLT with the lid on for about 5-10 minutes. I dumped the water out when it was time to add the strike water.

To get to 154, I heated my strike water to 173 degrees, added the strike water then the grains. It held at 154 for 20 minutes and then dropped over the 60 min time to 149. The recipe called for 13.75 qts for the 11 lbs of grain.

My question: Where did I go wrong to keep the temp consistent throughout the mash?
(My MLT is a 10 gallon rubbermaid cooler.)

Your process sounds good, you are likely just losing heat from the lid. You can drill a few holes on the top of the lid and fill it with some foaming GreatStuff or afix a hunk of styrofoam under the lid to better insulate it.
 
I use the same cooler and what I do is I will heat my strike water about 7 to 8* above my strike temp. That way I preheat the cooler without wasting any water. It usually takes about 10 to 15 minutes for the water in the cooler to cool to strike temp, and over my 60 minute mashes I only loose 1 degree.. Maybe try a wet towel on-top or something..
 
+1 what tally said. I have the same cooler and heat my strike water higher to compensate for a room temp mash tun. I only lost a degree over an hour this last Sunday. My only advice is to not open the lid once you start mashing to take another temp reading. Let it go for an hour and then see what the temp is. I bet you won't lose as much as your first mash. I am only on my fourth all grain brew and I am finding that it is big time trial and error. The good news is it will still make beer. That's why this hobby is so fascinating to me. You mashed lower than you intended, so will get a beer that is lighter in body than you might have expected. Brew the same recipe with a 5 degree higher mash temp and you will get a different beer altogether. (I have so much to learn, I love it!)
 
Rerun said:
+1 what tally said. I have the same cooler and heat my strike water higher to compensate for a room temp mash tun. I only lost a degree over an hour this last Sunday. My only advice is to not open the lid once you start mashing to take another temp reading. Let it go for an hour and then see what the temp is. I bet you won't lose as much as your first mash. I am only on my fourth all grain brew and I am finding that it is big time trial and error. The good news is it will still make beer. That's why this hobby is so fascinating to me. You mashed lower than you intended, so will get a beer that is lighter in body than you might have expected. Brew the same recipe with a 5 degree higher mash temp and you will get a different beer altogether. (I have so much to learn, I love it!)

I heated my strike water up to 173 degrees and nailed the 154 -- it held for 20 minutes before dropping a degree.

Now I have a digital thermometer with wire probe. I keep it in throughout the mash with the lid turned most of the way (but not all the way to mess the cord). That's how I monitor the temp throughout the hour. I so this because I saw an AG video where the guy did not lose any heat.
 
tally350z said:
I use the same cooler and what I do is I will heat my strike water about 7 to 8* above my strike temp. That way I preheat the cooler without wasting any water. It usually takes about 10 to 15 minutes for the water in the cooler to cool to strike temp, and over my 60 minute mashes I only loose 1 degree.. Maybe try a wet towel on-top or something..

Tally, my strike water was 173 and I nailed the 154 for 20 minutes. I added the grain as soon as I was done putting the strike water in. I expanded a little more in the comment above.
 
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