120 Qt. cooler for mashing

I mashed my first batch in my new 120qt. mash tun and had problems getting a consistant temp. throughout the mash. I must have stirred the mash for 5 minutes but I kept reading a 4 degree difference from one end of the cooler to the other. I doubt that it was a due to a thick mash as I was no-sparging so I had roughly 2/3 of my total water volume in the tun to start. I ended up having to add boiling water because I missed my mash target temp. pretty badly and this helped to even out the temp. eventually. I’m just wondering if anyone else has the same problems when they use larger coolers to mash? My concern is that I’m going to have a heck of a time hitting my mash temp. if one side of the tun is at 146F and the other is at 150F early on in the mash.

Second, how bad of a hit to efficiency do you assume to take when you no sparge? I did a Baltic Porter which was supposed to end up in the 1.080 range at 60% eff. (good for me unfortunately) and I missed that by quite a bit. I don’t really all that much about great eff. but I want to hit my OG for proper pitching rates, especially, with a big lager like this.

Thanks.

Bigger coolers soak up more heat to reach equilibrium, so up your usual strike temp a little compensate. I use a stainless paddle to stir my 30-gal cooler, usually with 15 gallons of water and 40 or so lbs of grain and reach constant temp in a couple minutes.

Assuming full conversion in the mash, no-sparge efficiency is the volume of wort in the kettle divided by the volume of water used to mash. So, larger grain bills will cause a drop in efficiency because the grain is absorbing more wort and you can boost efficiency by making sure that you thoroughly drain the MT.

Don’t no if anyone is interested in this but I’ll post it anyway.

http://beerdujour.com/Howtobrewabigbeer.htm