Mash tun temperature stabilizer

[Jlahey]

I am having a hard time maintaining consistent temperatures in my mash tun during the mash rest. I have a bayou classic 8 gallon mash tun with a ball valve and screen and a false bottom. Depending on the grain bill I heat up the strike water to roughly 160 to 167, add grain, mix, and let sit until temps start to drop. I'll then throw a little heat on it to bump up the temp while mixing thoroughly. The problem is that when I take readings, the temps vary quite a bit, 7 degrees at the most.
So my idea to maintain a more consistent temperature is to have a separate pot with 4 gallons of water on the stove with it set at the desired mash temp. Then place a submersible water pump in there and have it pumping water to my wort chiller, which would be placed directly in the mash. The water would then recirculate back into the pot holding water. I posted a picture to get a better picture.
I have tried searching for something like this but haven't found any information about it. So my question is does anyone see any potential problems with this idea, and does anyone know of a reasonably priced submersible pump, able to withstand heat, to circulate the water. Thanks in advance

 

[Onkel_Udo]

I'll then throw a little heat on it to bump up the temp while mixing thoroughly. The problem is that when I take readings, the temps vary quite a bit, 7 degrees at the most.

Have you considered adding insulation to the pot? Two layer of a bubble wrap make a huge difference.

Alternatively, if you pot fits in you oven, ther is about no better temperature controller. Heat is up to about 5 degrees over you mash temp. slap in the pot, turn it off or turn it back down to your mash temp.

 

[douglasbarbin]

Having a slightly thinner mash might help, too.

 

[rlmiller10]

I am having a hard time maintaining consistent temperatures in my mash tun during the mash rest. I have a bayou classic 8 gallon mash tun with a ball valve and screen and a false bottom. Depending on the grain bill I heat up the strike water to roughly 160 to 167, add grain, mix, and let sit until temps start to drop. I'll then throw a little heat on it to bump up the temp while mixing thoroughly. The problem is that when I take readings, the temps vary quite a bit, 7 degrees at the most.
So my idea to maintain a more consistent temperature is to have a separate pot with 4 gallons of water on the stove with it set at the desired mash temp. Then place a submersible water pump in there and have it pumping water to my wort chiller, which would be placed directly in the mash. The water would then recirculate back into the pot holding water. I posted a picture to get a better picture.
I have tried searching for something like this but haven't found any information about it. So my question is does anyone see any potential problems with this idea, and does anyone know of a reasonably priced submersible pump, able to withstand heat, to circulate the water. Thanks in advance

No clue about a pump that will take the heat. But do you insulate your kettle? Or it might be cheaper (and I am a cheap bastard) to just make a cooler mash tun.

It is going to be hard to get an even temp, even with your cooler/heater idea, in a non-insulated vessel. The grain is actually pretty good at insulating so where ever you apply the heat, be it the bottom with a burner or the middle with a cooler/heater you will still get a fairly steep temperature gradient across the mash. It might even be worse with the cooler/heater as you will not be able to stir very well.

Your best bet is to insulate so the temperature can stabilize across the grain bed and be held there.

 

[Jlahey]

I haven't gone crazy with insulation. Just wrapping the pot with a large blanket. And the lowest setting on my oven is 200 and it's too small for my mash tun

 

[Conan]

Your idea is basically a RIMS but with the 'immersion' part in the tun, not circulating the mash through a coil immersed in hot water. Wrapping the tun with a high temp blanket should help significantly. As for pumps to go with your original thought you could use a traditional March or Chugged pump. Not cheap, but they are proven to work. Also not submersible but you can just run as hose into the hot liquor tank. Kyle

 

[Natdavis777]

a few wraps of some reflectix will do you wonders... And you can make it to where it just slips on and off the pot with ease. I have a 4 layer wrap with a lid made from it as well, and lost 0.5F over a 75 min mash on my last brewday in my 40F garage.

 

[pantherburn]

Where's a good source(i.e. cheap) for reflectix?

 

[blizz81]

Your idea is basically a RIMS but with the 'immersion' part in the tun, not circulating the mash through a coil immersed in hot water. Wrapping the tun with a high temp blanket should help significantly. As for pumps to go with your original thought you could use a traditional March or Chugged pump. Not cheap, but they are proven to work. Also not submersible but you can just run as hose into the hot liquor tank. Kyle

Coil in hot water would be HERMS...but HERMS might be a better idea, especially if done like this:

https://www.homebrewtalk.com/f257/50-dedicated-herms-468563/

 

[Conan]

Coil in hot water would be HERMS...but HERMS might be a better idea, especially if done like this:

https://www.homebrewtalk.com/f257/50-dedicated-herms-468563/

Thanks...I wasn't remembering which was which, and thought I was backwards, but made an RIMS acronym up to fit my needs in my head. Kyle

 

[tdbc2011]

I am having a hard time maintaining consistent temperatures in my mash tun during the mash rest. I have a bayou classic 8 gallon mash tun with a ball valve and screen and a false bottom. Depending on the grain bill I heat up the strike water to roughly 160 to 167, add grain, mix, and let sit until temps start to drop. I'll then throw a little heat on it to bump up the temp while mixing thoroughly. The problem is that when I take readings, the temps vary quite a bit, 7 degrees at the most.
So my idea to maintain a more consistent temperature is to have a separate pot with 4 gallons of water on the stove with it set at the desired mash temp. Then place a submersible water pump in there and have it pumping water to my wort chiller, which would be placed directly in the mash. The water would then recirculate back into the pot holding water. I posted a picture to get a better picture.
I have tried searching for something like this but haven't found any information about it. So my question is does anyone see any potential problems with this idea, and does anyone know of a reasonably priced submersible pump, able to withstand heat, to circulate the water. Thanks in advance

This is what I do and I use the water in my HLT. I have a 120 v element from homebrewstuff.com and a controller. It works great, in warm weather the HLT is set at 2 degrees above MT target temp and in colder weather about 4 degrees above. The good thing about it is that I can adjust the HLT temp slowly as I need an adjustment.

It works so well that I no longer insulate the MT. I do recirculate the MT the entire time and stir twice during the mash. My efficiency is normally around 85%

https://www.homebrewtalk.com/f257/coiled-temperature-controlled-mash-tun-475400/

 

[madscientist451]

I had a similar problem. I got tired of the temperature swings and got a round cooler, added a valve, put a BIAB in and was ready to mash. If the temp. drops, I just use a step mash calculator to determine how much hot water to add to bring it up. I keep some hot water handy on the stove when mashing. My beer got a lot better when I added the cooler.

 

[brewkinger]

a few wraps of some reflectix will do you wonders... And you can make it to where it just slips on and off the pot with ease. I have a 4 layer wrap with a lid made from it as well, and lost 0.5F over a 75 min mash on my last brewday in my 40F garage.

I'm gonna say this is your best option. Wrap the kettle in reflectix, cut a circular piece to fit inside on top of the mash and wrap in a blanket.
Your way sounds cool, but this way is cheaper and way more efficient.