Recommendations for recir in cooler mash tun?

[Homercidal]

Hey all, I'm going to be finishing my EHERMS at some point this fall/winter (If other projects can back off of me for a moment!)

Before I get to finishing it, though, I thought about doing a trial recirc to see how it will pump from the cooler mash tun and back in.

I have a 10 gallon rectangular mash tun with a copper manifold, 1/2" output. I'll be using a March pump to push the wort back to the cooler.

I'm wondering if I should mash a bit thinner? Would I need a grant? What kind of system for putting the wort back on top of the grain bed?

 

[acidrain]

If you mash a bit thinner, you'll have more wort to recirc, and a higher level above the grain, which is a good thing for recirc, but it also means less sparge amount, which could hurt your efficiency.
The larger square MT sounds like it may work better for larger batches since you'll have the advantage of being able to mash with a little more head space over your grains.
The difference in a bigger beer where you'll end up with less wort than a lower gravity beer will be less head space over the grains, so if you do big beers, and want the wort level nice and high over the grains, then you may be doing a full volume mash, which would suck for efficiency, but it's only a few pennies in grain..
I like to recirc with about an inch over the grain, and although I lay my hose right on the grains, a lot of people use a colander or aluminum foil with holes punched in as a defuser.
I don't use a grant, but I've had stuck mash due to too aggressive of a recirc.
A grant is not a bad idea.
I mash in a keggle & HERMS, so take what I've offered for what it's worth.

 

[Homercidal]

I wouldn't think you'd lose a ton of efficiency with a smaller sparge volume. Some, sure, but the mash portion will also be diluted, meaning there is less sugar in teh grain for the sparge to rinse.

I did a 22 lb. mash yesterday for a Wee Heavy and it seemed as though there was plenty of room for a thin mash. I have to brew that same recipe again, only bigger, so that may be a decent test of the capacity. I will try recirculation and see what happens. Worst cast it doesn't work and I know better how to proceed.