Making an All-Grain Cooler... Big Box or Tall Round?

Well, I’ve finally decided to move into the all-grain brewing arena. In fact, I can’t believe I haven’t done that already. Knowing what I know now after 2 1/2 years of extract brewing, I should have went into all-grain after my second or third batch. Anyways, I’m going to build my own all-grain brewing mash tun. I want one that will permit me to brew 10, 15, and even 20 gallons (yeah, I drink a lot of home brew). I’ve read plenty about how to do this, and viewed a few videos on the process. It seems that the term “stuck sparge” is always mentioned when it comes to all-grain. My question is this… If I want to brew 10-gallon batches, do I need to buy an appropriate round cooler or can I go with the large rectangular coolers I see at Wal-Mart, Lowes, Home Depot, etc? The round coolers are perfect for 5-gallon batches, and I see them everywhere. But, I can’t find them in anything larger. Coleman makes a 100-quart (25-gallon, I believe) chest cooler that is perfect for what I want to do. Problem is, I’ll need a good solution for fighting off stuck sparges. Thanks.

I use a 72 qt Extreme from coleman for 5g batches and I don’t even fill it up halfway so you could easily do 10 gallon you’d be pushing it with 15 gallon brews. MullerBrau on these forums does like 25 gallon brews so he might be the guy to talk to.

I’m wondering if you would be better off having multiple mashtuns to accommodate smaller and larger batches maybe

[quote=“mattnaik”]I use a 72 qt Extreme from coleman for 5g batches and I don’t even fill it up halfway so you could easily do 10 gallon you’d be pushing it with 15 gallon brews. MullerBrau on these forums does like 25 gallon brews so he might be the guy to talk to.

I’m wondering if you would be better off having multiple mashtuns to accommodate smaller and larger batches maybe[/quote]
Multiple mash tuns… never thought of that. I’m going to give that some consideration. Thanks, Mattnaik.

I have used double buckets with a million holes drilled in the inside one, a round water cooler with one of those pizza pans with a million holes for a false bottom, a rectangular with a home made (double) bazooka screen and a 25 gallon stainless with a commercial made false bottom. The container has some to do with it but I have found the false bottom makes or breaks the run off.

Depending on what mash tun you decide you may need to do some experimenting with the false bottom. For batch sparging I think the rectangular would be the least expensive and workable. You can see a photo of my “bazooka” type here that I used in a rectangular viewtopic.php?f=5&t=122227&start=15

To do 20 gallons with a single MT it will have to be pretty big. A high gravity beer in my 25 gallon at 1.25 qts to lb of grain fills it almost to the top. To heat enough water for a plastic cooler or two you will need a large kettle or stagger the batch times. Make sense?

I am definitely a fan of the big rectangular cooler. I have a 60 qt. rubbermaid which is big enough for the biggest 5 gal batches and would do 10 gal if I had a big enough kettle. So far I have only filled it about half full.

This particular cooler has two annoying features: the split lid is a bit awkward when trying to dump it out especially since the lid only opens just past vertical, and the drain port is in the middle of the long side which makes it slightly less efficient at draining completely. If I did it again I would get the Coleman extreme.

I use a 10-gallon Igloo water cooler and it’s difficult to stir the sparge water into the grain. I assume a larger surface area/shallower grain bed would be easier to mix for batch sparging.

If you haven’t read it yet, go to dennybrew.com Denny Conn explains his very simple batch sparge system in excellent detail. He has a growing army of followers. The short length of stainless mesh he recommends doesn’t sound like it should work well, but his followers swear by it, and considering the low cost it would be wort trying.

rectangular. cheap n easy. just make sure it’s BLUE

I’ve got one of each. I tend to use the 10 gallon round more often for my “normal” gravity beers and use the (blue) rectangular one for the larger batches when I need to hold more grain.

They both work great.

Yep.

I have a 48 qt., a 70 qt., and a 152 qt. I use whichever one fits the circumstances. I have found that with a rectangular you get more volume for your money, and the larger opening makes them easier to use than a round cooler.

Go big if you can only buy one to start. I use a 30-gal rectangle as my main MT and can make everything from a 5-gal to a 1-bbl batch and when you get into that size they are very-insulated (like 5-day insulated) so you won’t lose heat on the smaller batches. Like Denny, I have multiple coolers for different sizes and yes, it’s easier to work with a 12-gal cooler if you’re doing a smaller batch, but for one-and-done, go big.

Though I would caution going too big could result in more dead space. Dead space volume remains constant regardless of the batch size. It all depends on the design of the mashtun of course but if you have a gallon of deadspace in your mashtun, that gallon when you’re brewing a 5 gallon brew vs a 20 gallon brew is significant and could impact your efficiency.

+1 to the BLUE rectangular 77 qt from Coleman. I’ve brewed anything from a 5 gallon batch of 1.040 beer to a 20 gallon batch of IPA. I also did 11 gallons of barley wine with it and maxed it out! Flexibility, and as mentioned by Denny, ease of use puts my money in the rectangular department. I owned a round igloo before the rectangular and didn’t like it that much.

[quote=“mattnaik”]Though I would caution going too big could result in more dead space.[/quote]A properly constructed MT with a pickup tube and stainless braid won’t have any deadspace to worry about.

Depends on the design of the cooler. I bought an Igloo “cube” cooler that had well over a gallon of deadspace due to the location of the outlet. I used it as an MT 2 or 3 times and then bailed on it.

The coleman Xtreme (I have the 72 quart) has a drain channel which really helps mimimize dead space.

[quote=“HD4Mark”]I have used double buckets with a million holes drilled in the inside one, a round water cooler with one of those pizza pans with a million holes for a false bottom, a rectangular with a home made (double) bazooka screen and a 25 gallon stainless with a commercial made false bottom. The container has some to do with it but I have found the false bottom makes or breaks the run off.

Depending on what mash tun you decide you may need to do some experimenting with the false bottom. For batch sparging I think the rectangular would be the least expensive and workable. You can see a photo of my “bazooka” type here that I used in a rectangular viewtopic.php?f=5&t=122227&start=15

To do 20 gallons with a single MT it will have to be pretty big. A high gravity beer in my 25 gallon at 1.25 qts to lb of grain fills it almost to the top. To heat enough water for a plastic cooler or two you will need a large kettle or stagger the batch times. Make sense?[/quote]
Yup. Makes perfect sense. I’m into brewing high gravity beers like Imperial IPA’s and Belgium strongs. Before I initiated this question, I didn’t even consider the amount of grain could fluctuate depending on the beer.

Why blue?

[quote=“tookalisten”]I’ve got one of each. I tend to use the 10 gallon round more often for my “normal” gravity beers and use the (blue) rectangular one for the larger batches when I need to hold more grain.

They both work great.[/quote]
Yeah, it seems that if I really want to do this right, and have options, I’ll need buy several sizes and build from there.

Why blue?[/quote]

Everyone knows blue coolers are better than red!

Why blue?[/quote]

Everyone knows blue coolers are better than red![/quote]
Yes blue coolers are known for their increased efficiency.

[quote=“Loopie Beer”]

Yes blue coolers are known for their increased efficiency.[/quote]

Exactly. You get 135% efficiency with blue coolers. That means that after about 10 brews, a bag of grain magically appears in your garage. :wink: