Mash tun size?

I'm in the processes of building a mash tun and I'm trying to decide on what size cooler to purchase. In most cases bigger is better but I assume that the least amount of head space in the cooler the better for insulating the mash. However, this limits me on the amount of grains I can use for my 5.25 gallon batches. What are your thoughts on a 36 quart cooler? Does this provide enough flexibility or should I consider a bigger cooler?

I would go with a 10 gallon cooler (40 quart, round) or as large as you can afford. I have a 70 quart that I'm going to try converting into a MLT, again... That way I can mash my big brew grain bills without worry... Or go to 10 gallon batches without getting anything else...

I went with a 10 gallon just in case I want to make larger batches or bigger beers. I didn't notice any loss of temp when I did a 5 gallon batch, however I did pre-heat my mash tun beforehand so I'm sure that had an impact.

Depending on where you are, and the temperature of where you're mashing, pre-heating the tun makes a lot of sense... Maybe not in places where it's in the 70's this time of year, but up north it does (wind chill is putting it into the negative numbers through tomorrow up here)...

It was pretty cold that day. Sure, I was brewing indoors but it's still fairly cool. Didn't lose a single degree.

MeatyPortion said:

It was pretty cold that day. Sure, I was brewing indoors but it's still fairly cool. Didn't lose a single degree.

Click to expand...

THAT is the most important part... Do whatever you need to lose the least amount of heat in the MLT... That's what's drawing me back towards using a cooler... At least during the winter... Plus, having 70 quarts of capacity to mash in (minus what the screen will take up)... Will make brewing MOAB a bit easier, I'm sure...

BendBrewer said:

https://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/

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Thanks for the link. If I'm reading it right a 36 quart mash tun has a maximum capacity of:

5.25 gallon 1.106 gravity
10.50 gallon 1.050 gravity

So, if I stick to 5.25 gallon batches it looks like I can rule out strong ales, bock lagers, and imperial stouts.

I think you'd be better off planning on making bigger brews, and not having 70% efficiency (until you have the system dialed in)... Plan on 60%-70% initially (hoping for better) for the biggest brew you can imagine ever making...

For me, that means converting my 70 quart cooler into a mash tun makes sense (my BIAB efficiency is 78-82%, will need to dial it in again for cooler MLT use)... I'd rather plan to have MORE capacity than I think I'll use, than just enough to eek by... I'd also rather be ready for making 10 gallon, big brews, without purchasing additional hardware... I also like to use more than 1.25qt/# when I mash... I seem to get better extraction that way... Basically, I mash with as much water that I can, with the grain bill, and then sparge with what's left... With the 32 quart pot, that's done pretty well (been a little tight in the sparge pot, but that's about to change)...

Either way, unless it's a large price difference between cooler sizes, get the biggest one you can afford. I don't think you'll ever regret going that route... I've yet to hear anyone say that they wish their MLT/converted cooler was SMALLER... Besides, unless you drill the cooler (most large ones come with a drain spout) you can always convert it back into a cooler and use it.