[S. cerevisiae]

I disagree with those who telling you go bigger.  I believe in picking the tool for the job.   A small batch does not have as much specific heat capacity as a larger batch, and a bigger than required cooler represents a larger thermal sink.  I have brewed 1.072 5.5-gallon batches with a 5-gallon beverage cooler.  If am brewing a beer bigger than 1.072, I am brewing a smaller batch because it is going to get bulk conditioned and bottled.  If you are certain that you will be brewing mostly 3-gallon batches, go with the 5-gallon cooler.  It's smaller, easier to store, and holds temperature better when brewing small batches.  Life is too short for compromise brewing.

[dzlater]

Thanks for the replies, I think I'm going with a 5 gallon cooler. If I want to make a big beer, I may have to scale back down to 2.5 or 3 gallon. But I think the 5 gallon cooler will be serviceable as I learn more.

I'd recommend a rectangular cooler since they're easier to use and less expensive.  A 48 qt. would be perfect for you.

 I switched from using a five gallon round to a large rectangular cooler.
The larger rectanglar cooler didn't drain near as well. It just seemed like over kill to me. Plus the smaller one is easier to tote to the compost pile.
I went back to the round one unless I'm doing a high gravity batch that won't fit in the 5 gallon.

[beersk]

When I brewed 4 gallon batches, I used a 5 gallon round cooler and it was perfect. I bumped my batch size up to 4.75 and am happier with my 36qt Coleman Xtreme cooler (this is a really good option for you). The 5 gallon cooler is definitely easier to clean if you're just cleaning in your kitchen sink.

[denny]

I disagree with those who telling you go bigger.  I believe in picking the tool for the job.   A small batch does not have as much specific heat capacity as a larger batch, and a bigger than required cooler represents a larger thermal sink.  I have brewed 1.072 5.5-gallon batches with a 5-gallon beverage cooler.  If am brewing a beer bigger than 1.072, I am brewing a smaller batch because it is going to get bulk conditioned and bottled.  If you are certain that you will be brewing mostly 3-gallon batches, go with the 5-gallon cooler.  It's smaller, easier to store, and holds temperature better when brewing small batches.  Life is too short for compromise brewing.

I have no problem using my 48 qt. cooler for small batches.

[denny]

I switched from using a five gallon round to a large rectangular cooler.
The larger rectanglar cooler didn't drain near as well. It just seemed like over kill to me. Plus the smaller one is easier to tote to the compost pile.
I went back to the round one unless I'm doing a high gravity batch that won't fit in the 5 gallon.

How large?  I respect your experience, but mine was different.

[HoosierBrew]

I have no problem using my 48 qt. cooler for small batches.

Same here, Denny.

[Joe Sr.]

I've got a five gallon round cooler.  I kinda wish I'd gone bigger and will wind up doing so at some point.

I can't speak to heat loss, since I haven't used a bigger cooler yet, but I really dont' relish having yet another cooler kicking around and taking up space.

Get the right cooler the first time.  Based on everything I've read, I'd go with Denny's recommendation here.

[JT]

I used a 10 gallon round before upgrading to a RIMS and I no longer use a cooler.  If I had it to do over again, I'd have gone 5 gallons for the cooler size. 

Sent from my SCH-I545 using Tapatalk

[curtism1234]

What about the filtering aspect of a round cooler vs rectangle?

A client of mine has brewed for decades and told me to go with the round because the grain bed will be taller and act as a better filter. Of course this guy is a very meticulous and to style kind of guy so he may be over-exagerating for most people's expectations.

[a10t2]

What about the filtering aspect of a round cooler vs rectangle?

I'm sure you you could get a grain bed shallow enough that it's physically impossible to avoid channeling, but that isn't a practical concern IME. Manifold design, flow rate, and vorlauf technique are all going to be bigger factors.

For example, I routinely mash an 8.5 lb grist in a 50 qt cooler and have no problem setting up for a good lauter.

[Slowbrew]

I have used 5 gallon and 10 gallon round coolers for 5 gallon batches.  They both worked without much issue.  The 5-er would get tight on space on some beers.  The 10 always had enough head space for anything I threw at it.  I had to preheat either one to make sure they held temp.

I now use a 50(ish) quart rectangular cooler and am very happy with.  Plenty of space, yet small enough for all my typical recipes.  I preheat this one too and see a bit more temp drop on longer mashes than either of the round coolers.

My reasons for changing coolers over the years have been:

I was broke and 5 gallon was cheaper than 10,
My inner Tim The Tool Man decided bigger was better so I bought the 10 gallon
Two 10g coolers cracked inside and could not be repaired so I listened to Denny (and the gang) and bought a Coleman Extreme rectangular. 

They all worked.  Having so much access for stirring in the Coleman is a big advantage too.  Barring anymore physical issues with coolers I would guess I've bought my last one.

If it helps anyone...

Paul

[denny]

What about the filtering aspect of a round cooler vs rectangle?

A client of mine has brewed for decades and told me to go with the round because the grain bed will be taller and act as a better filter. Of course this guy is a very meticulous and to style kind of guy so he may be over-exagerating for most people's expectations.

If you batch sparge, as I do, then grain bed depth doesn't matter.

[S. cerevisiae]

I started out using Rubbermaid/Gott 10-gallon beverage coolers.  I then switched to using Rubbermaid 7-gallon beverage coolers (Home Depot used to carry this size) before finally settling on Igloo 5-gallon industrial beverage coolers for my mash/lauter tun and hot liquor back.  Bigger is not always better, and a round cooler works for all lautering techniques due the pressure equalization that occurs in a cylinder (one of the reasons why pipes are round).  When brewing small batches, a 5-gallon beverage cooler sinks less heat at mash-in and maintains temperature better than a larger cooler.   A 5-gallon beverage cooler is even more efficient when brewing 5.5-gallon batches up to its capacity.

One last thing: if you continuous sparge like I do, grain bed thickness, tun geometry, and false bottom design all make a difference.  If you think that you will ever want to continuous sparge, think round, not square or rectangular.  The goal in continuous sparging is to have equal fluid flow down through the mash bed.  A cylinder works best for continuous sparging due to the fact that pressure is distributed equally around the perimeter.  With a square or rectangular shaped tun, pressure forces concentrate in the corners.

[Joe Sr.]

If you batch sparge, as I do, then grain bed depth doesn't matter.

if you continuous sparge like I do, grain bed thickness, tun geometry, and false bottom design all make a difference. 

The answer to the question, as in most cases, appears to be "it depends."

This is what's so great about brewing.

I'm also starting to think that Denny and Mark are like the Yin and Yang of the home brew world.  Batch sparge/stir plate or continuous sparge/shakey-shake, whichever you prefer.  Or mix 'em up.

[S. cerevisiae]

I guess that we are like the yin and yang of the homebrew world.  However, that does not stop us from having a civil conversation in person.  Maybe, it's because Denny is so darn likable in person.    It's difficult to find someone with a more "glass is half full" attitude than Denny. However, then again, Denny is retired while the rest of us are still doing the grind.