FensterBos

Recipes 

I built a mash tun out of a 52 quart rectangular cooler. For many, many batches I was getting HORRIBLE temperature control and it was really hurting my efficiency. I have a lot of headspace when I do average gravity beers and I lose a lot of heat because of it.
What are some options or methods you have used to control temperatures with coolers that have a lot of headspace? Thanks!

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Waaaay behind on brewing, but doing some planning.

michaeltrego

Recipes 

Are you preheating your tun before mashing in? If not, put several gallons of the hottest tap water in there while you are heating your strike water. Is your cooler lid insulated? If not, you can drill small holes and fill it with Great Stuff foam. I have a 50 quart square cooler, and I don't worry about the headspace, but by using those two techniques my mash stays within one degree for the whole mash.

audger

Recipes 

probably not worth it for such small scale, but worth a mention... when you have a large open tank of hot water, you can reduce your evaporation rate and heat loss considerably by adding some plastic insulation balls to it. they form a blanket over the top of the liquid.

like:
http://www.eccllc.us/applications_advantages.php

FensterBos

Recipes 

As you can see I haven't checked this in a while.
I've tried preheating the tun the last time I mashed; I heated up my strike water about 20 degrees hotter than what I would normally and added to the cooler. Once the temperature reduced to my target temperature then I added the grain to reach my target mash temperature. I still saw significant loss in temperature, though.
The lid is pretty hollow so I'll try using your foam insulation idea next.

__________________
Waaaay behind on brewing, but doing some planning.

TyTanium

Recipes 

Cover & wrap with a blanket. And I always bring my tun inside where there's no wind.
I lose maybe a degree or two over an hour.

ekjohns

Recipes 

I have tried the great stuff on 2 separate lids and every time the foam just collapses and I don't get that nice thick foam in there. I am not sure if I am adding to much but I can never get it to work. Any advice on my 3rd attempt? What I have been doing so far is using some insulation board cut to rest on top of the liquid which gives me zero head space. The only problem with this is it has to be wrapped in saran wrap to keep it from directly contacting the mash.

TyTanium

Recipes 

Greatstuff needs air/moisture to activate & expand...if you're pushing into a small, relatively sealed space, it's not much different than staying in the can. Some guys have cut the top off their lid, filled with foam, cut it down, then put the lid back on.

But again, I just use a blanket. Don't overthink it or create more work for yourself, IMO.

royale

Recipes 

ekjohns,

When you rest your pad on top of the mash, did you manage to cut your heat loss? I have a 5 gallon rubbermaid cooler tun and I am losing heat like crazy, 7-8 degrees in an hour. I even double wrapped the outside of the tun using Reflectix from HD but It's not helping much. The lid of the cooler got really hot and I know that they are hollow so it is the only culprit I can think of.

kh54s10

Recipes 

I saw a thread where someone took sheets of Styrofoam and cut to the shape of the tun and covered them with tape or something then just filled the headspace with these. They float on the top of the mash.

kh54s10

Recipes 

For filling the lid of the tun with Great Stuff, you could drill some holes then squirt in a little foam as far out to the ends as possible, let that set, then add more and let it set. Go in small additions until the lid is filled.