Mash Tun. Round or Rectangular Cooler

[Hebby5]

Thinking about going AG and will need to build a Mash Tun out of a cooler. I've seen videos and read testimonials about both round and rectangular coolers being used as MLTs. I'll be doing 5 gallon batches but realize that you need more volume than that.

Looks like you may have a little more "elbow room" with a 10 Rectangular Cooler over the round Rubbermaid 10G. Does one hold the temp better than the other? Any comments from the HBT peanut gallery?

I appreciate the help as always.

Chris

 

[DD2000GT]

Can't speak for how well the round is over the square - but I have the round 10 gallon igloo cooler (Home Depot Special) with the conversion plan I got right on this website. I loose less than 1 degree in an hour and get efficiencies around 75 - 80% consistantly.

 

[Hebby5]

I've seen instruction videos on cooler conversion on YouTube and step by step instruction (with pictures) on HBT. Awesome stuff. Just got to figure out which cooler to get. I think the round ones may store easier in my garage but the rectangular ones look easier to stir all grains.

 

[Bsquared]

are you going to Batch sparge? if the answer is yes, it does not matter the shape, just try to stay around the 10 gallon or 40qt size for 5gallon batches. if you go to big like 70qt with a 5 gallon batch, there is a lot of empty space and hitting your strike temp can be a little tricky especially on a cold day. At least thats my experience trying to mash in my 80qt cooler a 8lb grain bill...duh

If you plan on continuous of fly sparge you need to be more concerned about grain bed depth, and i think the consensus is the round cooler are better. Personaly I continuous sparge most my beers and I use a Square cube cooler. 40qt for 5gallon batches and 80qt for 10gallon batches. I'd just say avoid the rectangular cooler if you are going to continuous sparge, but I'm sure there are people who have been are successful with them too.

 

[Hebby5]

Looks like Sears has a good price ($20 each) for Coleman 48Qt coolers (rectangular). No time like the present to get started converting them.

Thanks!

Chris

 

[JoeyChopps]

Just my .02 I have read about guys with square coolers complain about the top leaking and lowering the temp over a period with the hd 10 gal drink cooler the lid screws on and probably seals better

 

[hypergolic]

I went with a 10 gallon round cooler and a false bottom, works great. I tried the stainless steel braid at first and I couldn't get it to work for the life of me. Other people say it works great, I am going to blame it on operator error.

 

[asterix404]

I actually just "upgraded" and went out and got the 10g home depot rubermaid cooler. It's exactly the same cooler as anywhere else but this is bright orange with home depot on the side. I switched from the rectangular Colman. The hardware is exactly the same. The home depot one is better, it keeps heat much better and is easier to manage. The top of the Colman is completely hollow so basically I really had to wrap is very very well. I love the home depot cooler conversion, hole thing was under 50$ and I lost less than a degree over several hours when I did actually wrap it which I am not 100% is needed but I do it out of habit anyway. It really keeps it's temperature very well. Also if you want to switch up to fly sparging, this is the only way to go.

 

[Tyru007]

can't speak for how well the round is over the square - but i have the round 10 gallon igloo cooler (home depot special) with the conversion plan i got right on this website. I loose less than 1 degree in an hour and get efficiencies around 75 - 80% consistantly.

+1

I lose 1-2 deg over 60 minute mash, 75% efficiency on most batches.

If you plan on batch sparging, get a bazooka screen.
If your going to fly sparge, get a false bottom.

 

[rjschroed]

I haven't ever tried a square cooler so I can only tell you my experience with my round 10 gallon cooler. It works great with the SS braid. . . as long your careful to make sure it stays on the bottom when you stir your grains. For that reason I'm seriously considering switching to a false bottom.

 

[jaycount]

I only have a rectangular but I can tell you the reason I went with it was because it was so much cheaper. I bought a 52qt igloo with a drain for $23, a 10 gallon round cooler was going to run me twice that. Just something to keep in mind.

 

[Rushis]

I second the batch sparge comment with the caveat that clever engineering can overcome any come drawbacks in a rectangular cooler. I have a 52 quart marine igloo cooler (costco special). It holds temp great and has the capacity to handle high gravity (>1.060) 5 gallon batches and moderate gravity (<1.050) 10 gal batches. Having recently put together a keggle, I am VERY pleased with the my choice to acquire the largest cooler MT in my budget at the time. Everyone wants to expand eventually

 

[Tyru007]

I haven't ever tried a square cooler so I can only tell you my experience with my round 10 gallon cooler. It works great with the SS braid. . . as long your careful to make sure it stays on the bottom when you stir your grains. For that reason I'm seriously considering switching to a false bottom.

It worked well but I could never get it to stay in the bottom.

 

[Felix534]

I currently use a round cooler with a braid. The one I have came from a water feed line for a toilet. (Brand new one, mind you... ) I put a brass cap in the braid and it keeps it at the bottom. Works well, all things considered! The mash temp barely drops over 60-90 min. Can't complain for the $50 or so I spent on it.

 

[TheMan]

I have used both. I prefer the round. You mentioned the rectangular being easier to stir, I think it's the opposite. A rectangular one sloshes around a lot when stiring and can spill over easier. The round one is taller and less prone to this.

That said, I batch sparge, and the results have been exactly the same. I get 81% efficiency with either tun using a braid. Both hold temp with only 1 degree loss. I would really just base it on which is easier for you to store and price. Neither is truly superior to the other, just preference.

 

[bniesen]

I batch sparge and don't see my self going to the fly sparge route so I use a 15 gal rectangle coleman extreme cooler with a copper manifold on the bottom. I re-use the original gasket with the weldless ball valve, no leaks whats so ever. I loose 1 deg over 60 minutes AND I have only done 5 gal batches so far. The lid is not hollow on mine. The trick is to preheat the cooler with hot tap water and don't go for a hollow lid.
I had used a 5 gal round (home depot) and was waiting for the local HD to carry the 10 gal. I had a hard time getting the ball valve to not leak and had to use silicone caulk to seal it, and I found that if you wrap the top with bath towels it will retain heat very well. It did hold the temp well but my rectangle cooler performs the same even without using the towels.
I went to the local HD recently and they had the 10 gal on sale for $30. I was a little upset but I like the one I have, plus it is handy to have it on wheels.

 

[DosGatosBrewing]

FWIW - I use the round 10G Rubbermaid cooler with a stainless strainer, and a ball valve. the screw on lid help keep temps within a couple of degrees for at least 75 mins. got it for $20 on craigslist. I've heard the square coolers' lids let heat escape. I'm sure either method is fine.

 

[TripHops]

I also use a round 10G Igloo cooler with 12" false bottom and ball valve. I find it very efficient and very easy to clean.

Trip

 

[EternalHoppiness]

Great advice above, but there is one more small thing in the round vs rectangular discussion that I wish I had thought of before making the decision: How easy is it to dump grain?

For those of us that can't just dump into a garden or compost pile, getting grain from the cooler to a trash bag can be inconvenient. A trash bag won't fit over the opening of my rectangular cooler, so I have to scoop grain out if I don't want to make a huge mess. However, I am guessing that with the round cooler one could just put the trash bag over the top and turn it upside down to dump. It's a small thing, but just one more consideration.

That said, I use the 36 qt coleman extreme with a braid and am pretty happy with it otherwise. The "trough" in the bottom for draining more liquid is great, and with preheating my drop over 60 minutes is less than a degree. This cooler is plenty big for "normal" 5 gallon batches (I've gone up to 15 lbs of grain so far), although it's really more like 32 qts of usable space rather than 36.

Either way, the cooler mash tun is a great invention!

 

[oregonparamedic]

I like to empty mine with a shop vac. Quick and easy and simple to dump after.

 

[Big-D]

I started out brewing on a 10g Gott type cooler mashtun. At the time, I was getting roughly 75 to 80 % efficiency. Problem is that you cant very easily split a batch with your buddies unless you are doing a pretty small beer. My friends and I like to brew beer at bout 7 to 8 ABV. I decided I would upgrade my system and purchased the 120qt Coleman Extreme5 cooler. I figured, bigger the better right??.. Wrong! I have never gotten such bad efficiency! For the record, I followed the design plans that Palmer has in his book... taking into consideration internal volume and how to create a good manifold for the grains to strain through. Over the last several batches I have been keeping pretty detailed records, and have come to the conclusion that because the large surface area of a rectangle cooler spreads out the grain bed too thin. This creates holes through the bed which the sparge water runs straight through and into your boil kettle, leaving you with a very bad efficiency. The last one I did (today) netted 50% efficiency.. the worst I have ever seen. Upon further investigation the grain in the mashtun was still sweet.. this after drawing off 13.5 g of wart. Obviously the conversion happened correctly in the mashtun.. but the sweet wart was not transferred to the boil kettle. For further information.. I continuous sparge over 30 to 45 minutes with a rainbar. I am throwing the cooler out, tomorrow. Never use this big of a cooler as a mashtun. depth of bed is king.

 

[wilserbrewer]

That cooler is likely a bad fit for fly sparging. Be a shame to toss It out. Try batch sparging, grain bed depth is not a factor.

You might end up preferring batch sparging and also getting good efficiency.

You could also try a no sparge batch with that huge cooler where all your water gets put in the mash, then you just run off and boil.

 

[Sbarnard80]

Be a shame to toss that cooler. Try batch sparging, grain bed depth is not a factor.

You might end up preferring batch sparging and also getting good efficiency.

You could also try a no sparge batch with that huge cooler where all your water gets put in the mash, then you just run off and boil.

+1. The sparge water is channeling straight to the manifold. It needs a way to rinse all the grain ie mix in. Batch and stir a bit. But even then it might be lower if the depth to surface ratio is too low.