What size mash tun?

[chefrand15]

I have a 5 gallon glass carboy and a 5 gallon stainless brew pot. What size mash tun is needed for a full carboy ferment? How big will it have to be to hold the necessary grains and water to mash?

 

[Brulosopher]

Huh? I'm a tad confused, but regardless, a 5 gallon mash tun would work... 10 or more is better, imo

 

[gilby_7]

I use a 10 gal. igloo drink cooler and it usually only gets filled to about halfway with my mash for a 5 gallon batch. I think you can brew a large variety of beers using a 5 gal. mash tun but you might have trouble brewing bigger beers with larger grain bills, but don't quote me on that. Home Depot is the cheapest when it comes to the igloo coolers I found. I spent the extra money to get the 10 gal. so I know I'll always have enough room no matter what I'm brewing.

 

[bleme]

Check out Revvy's post (#4) in this thread:

https://www.homebrewtalk.com/f39/5gal-mash-tun-316845/

 

[billf2112]

I have a five gallon tun, works great, but I do smaller batches. It holds up to ten pounds of grain with little head space. Zero head space alliws vetter heat retention.

 

[user 98891]

I have a 10 gallon. I think it's the perfect size. I can make 5 gallon batches, and even HG 5 gallon batches without any worry of filling it up. It's not that much bigger or more expensive than 5 gallon coolers. I just brewed a 5 gallon batch of 1.089 IIPA and I still had 3 inches of space in the top of the cooler.

 

[brycelarson]

You can sneak by with a 5 gallon until you want to do a big beer. On stouts and other large grain bill beers I'm often pushing my 10 gallon close to the max. If it's totally full I lose close to no temp over an hour - if I do a smaller beer and only have it half full I still only lose 1-2 degrees over 60 minutes.

To allow yourself room to do big beers I suggest getting a 10 gallon cooler.

 

[ajwillys]

If you really have a 5 gallon pot and expect to do full boils, you will probably be maxed out at about 3.5 gallon batches, 4 if you want to watch it REALLY close. At that batch size, you should be fine with a 5 gallon mash tun going with a pretty big beer. As others have mentioned, trying to do a 5 gallon batch with a 5 gallon tun is fine until you hit the really big brews.

Your biggest concern though in my mind should not be the mash tun but the pot and carboy. Generally you want at least a 7 gallon pot for a full boil on a 5-5.5 gallon batch. You'll also want at least a 6 gallon carboy for primary fermentation or you'll be blowing off a good portion of beer for every brew. At your current sizes, I don't see how you could possibly expect more than a 4 gallon batch, which is fine, but very "non-standard".

 

[duboman]

a 5 gallon tun will accommodate approximately 11 lbs of grain which will allow you beers around 1.050 or so. Since there is not a big difference between the cost of a 5 and going up to a 10 gallon, go 10 and then you can go big!