Switched to a round cooler mash tun-Good results

[Toecutter]

Since I started all grain brewing a few years ago, I have always used a 52 quart rectangular with good results , so I thought. My beers are pretty simple ales and Belgians with about 22 lbs of grain mash at 151-152 DG fly sparge, and I always hit at about 1.052 SG for a 10 gallon batch

I recently came upon some HD 10 gallon round orange coolers at a clearance outlet for $10 each. so I bought several, and converted one to a mash tun, using 1/2" soft copper tubing to fashion a circular manifold that fits snugly against the walls, and has slots on the bottom to pick up the wort.

Yesterday I brewed with it for the first time. I took a second cooler for sparge water, and elevated it, with a hose to the mash tun to gravity feed the sparge water. Worked like a charm.

What I was surprised to find is my starting SG went up to 1.062 which means my efficiency went up, using the same amount of grain. I always measure my SG right after the hot break, using my Hydrometer. No changes in any of my other processes.

Just surprised to find that the shape of the mash tun can make that much difference in efficiency.

 

[Stauffbier]

I've also suspected I might get better efficiency if I switched from my rectangular 52 qt. to a 10 gallon round. This thread has convinced me to give it a try..

 

[dhallowell]

Interesting that the shape seemed to matter. Too little data to know the cause, of course, but I'd note that the same volume in a cylinder vs. a cube has considerably less surface area - so your insulation efficiency has a better chance (all other things being equal).

 

[dmcman73]

The only thing I can think of is that in the larger rectangular cooler, the grains and sparge water are spread out and in one end of the cooler, there may be less water then the other end (do to the fact that there is a slope built into the cooler to allow water to drain out). With the round coolers, all the grain is pretty much "together" and is equally submerged in the sparge water.

Again, this could all be hot air but it's the only thing I can think of.