Question on mash tun cooler size

[Mark_]

Hey folks,

First, let me be clear: I have not yet started brewing. I am currently doing the research. I have been working with wine for a bit however and have most everything I need as far as equipment.

One thing I want to look into is building a mash tun cooler but I have no idea how big of one I will need to start. I am looking at brewing 3-5 gallon batches to start with as I already have 5 carboys of varying sizes. I was thinking a 5 gallon cooler would be good enough to start with and it looks like I will be using anywhere from 7-10 pounds of grains for an AG brew. I have no idea how much space 7-10 pounds of grain will need to steep and sparge well.

Any thoughts?

Thanks in advance!

-Mark

 

[rklinck]

A 5 gallon cooler is big enough to make most 5 gallon brews. You will run into trouble making beers with OGs above 1.070 or so.

 

[pfgonzo]

Bobby did a great info graphic here which might also help: https://www.homebrewtalk.com/f11/how-big-your-mash-tun-needs-123585/

 

[boxster20]

The "Can I Mash It?" calculator in the link below will help you evaluate how much grain and water a mash tun can hold.

http://www.rackers.org/calcs.shtml

A 5 gallon cooler should be good for you in most cases and if you are brewing a beer that needs more grain than your tun can hold, there is no shame in adding DME during the boil to increase the gravity.

If you think there is a chance you might increase your batch size in the future though, think about creating a tun that will be able to handle the increased batch sizes so you don't end up buying another cooler.

 

[LovesIPA]

The bigger the better. I would get a 10 gallon cooler for doing 5 gallon batches. If there is even a chance that you will do 10 gallon batches in the future, then get a bigger one. There is much less upfront cost in going larger than there is in replacing down the road.

 

[stpug]

The bigger the better. I would get a 10 gallon cooler for doing 5 gallon batches. If there is even a chance that you will do 10 gallon batches in the future, then get a bigger one. There is much less upfront cost in going larger than there is in replacing down the road.

I don't totally agree with this. More specifically, doing a low gravity 5g beer in a 15g cooler will leave you with huge temperature drops during the mash. Generally speaking, the less headspace there is above the mash the less temperature drop over the mash time. Naturally there are many other contributing factors to temp drops (and many ways of controlling mash temps) but headspace should be considered, or rather, avoiding too much headspace and/or insulating the headspace for smaller beers.

If you plan on sticking with 5g batches and don't plan on going over 6-7% beers then a 5g water cooler might just fit the bill. If you plan on occasional big beers and don't want to achieve the last bits of gravity by using malt extract then a 10g cooler might be a better choice. I have both a 5g and 10g water cooler, and granted the 10g cooler is not ready for production, but I've have not needed nor missed it up to this point. However, I plan on a partigyle IRS/porter in a month or so which WILL require a larger vessel than my 5g cooler so I can keep it all grain.

HTH!

 

[Clonefan94]

I have an Igloo 48 quart marine cooler. Granted, I usually get about 2 gallon/hour boil off rate, so my sparge water volume is probably a little bit more than most. But on my last beer, with a 1.062 gravity, by the time I got all my sparge water in there, I thought to myself, "Wow, is this could get messy if I stir like normal." Basically, what I'm saying is that I think 10 gallons would be my minimum for 5 gallon batches. I think I'd rather deal with a little extra head space than try and deal with a completely full mash tun and be trying to get all the doughballs out.

If space is an issue, I could see going smaller, but price wise, you are only talking a couple of bucks more for double the size of cooler, in most cases.

 

[pfgonzo]

CF, what are you using as your boil kettle and burner if you're getting 2ga per hour in boil off on a 5ga batch? That seems crazy!

 

[Clonefan94]

CF, what are you using as your boil kettle and burner if you're getting 2ga per hour in boil off on a 5ga batch? That seems crazy!

Yeah, tell me about it. I use a polar ware 40 quart pot - short, squatty and wide. And a Bayou classic Banjo Burner (the one that has the same style burner that you find on Blichmann). Once everything is up and going the burner I turn down to almost nothing and still get a decent rolling boil.

I think it all comes down to how wide the pot is and the surface area of the boil. If it's not that, I have no idea, but I'm pretty anal about my volumes and measuring them. It's spot on, 2gallons/hr.

 

[Mark_]

Man, I love this community. This is exactly the information for which I was searching. I swear I searched for it first but you guys really nailed it. I started off fermenting wine with a 3 gallon carboy and thinking, "Damn, I'll never fill that thing."

I am now up to 3-5 gallon carboys aging as well as 2-3 gallon carboys and several single gallons.

Soooo, with that said I think the 10 gallon is a good starting point for me!

Thanks everyone. You will see me around!

-Mark

 

[GrogNerd]

I don't plan on doing 10 gallon batches anytime soon, nothing much over 1.090 but I still got a 70 quart cooler. don't know how much temp I would lose to headspace because I spread a layer of aluminum foil over the top of my mash and haven't lost any

 

[boxster20]

I've heard some people cutting Styrofoam insulation to fit in their cooler and sit on top of the mash to reduce headspace. Aluminum foil probably works as well.

 

[BigRedHopHead]

I don't plan on doing 10 gallon batches anytime soon, nothing much over 1.090 but I still got a 70 quart cooler. don't know how much temp I would lose to headspace because I spread a layer of aluminum foil over the top of my mash and haven't lost any

+1 to this! I have a 72qt square chest cooler as well. Foil on top of grain bed works great! I did a thread a couple of weeks ago on my new cooler. Check it out....

https://www.homebrewtalk.com/f11/new-cooler-mlt-igloo-super-tough-393843/

 

[GrogNerd]

+1 to this! I have a 72qt square chest cooler as well. Foil on top of grain bed works great! I did a thread a couple of weeks ago on my new cooler. Check it out....

https://www.homebrewtalk.com/f11/new-cooler-mlt-igloo-super-tough-393843/

I read that thread and was surprised you had issues with your 70qt extreme leaking. i haven't had any problems with mine.

pic of the manifold before i drilled holes and added my bulkhead attachment

 

[BigRedHopHead]

By mistake when the cooler was on the floor I stepped on the ball valve, bending the spigot opening. Since I did not reinforce the spigot hole the liner on the inside had the washer and oring pulled into the hole. I tried repairing and resetting everything but the liner was warped. In any case I highly suggest reinforcing the spigot hole with PVC as Bobby M recommends.