Looking to upgrade my old Igloo round Mash tun. High Gravity beers are suffering. Was thinking maybe a pan and rims or herms? Any suggestions?
How about a bigger rectangular cooler? How big are the big beers? And by “suffering” do you mean quality or efficiency?
Lack of efficiency. The grain ends up over the 4"-8" bed that is recommended. I’ve heard square coolers have efficiency issues as well?
Depends on what you mean by efficiency issues…batch sparging in a rectangular cooler I can get up to 85% efficiency on a 1.100 beer. But that’s because I use a very large cooler for it. For beers in the 1.080-85 range I get around 80-83% in my 70 qt. rectangular.
And who says a 4-8" grain bed is recommended?
I’ve not heard the 4" to 8" recommendation before this. I did a 1.062 beer this past weekend and if I were to dump the entire kettle in the fermenter I would have gotten 81% BH efficiency with a 10" deep mash. I instead used a spigot and stopped short of draining the trub from the kettle and only got 65% BH efficiency.
I’ve used a 60 qt igloo cube for a few years and primarily for 5.5 gal batches. I just upgraded since I’ll be brewing for two from now on. My 100 qt igloo re tangy last extreme cooler will have its maiden voyage Saturday with an 11 gallon batch of a 1.105 Russian imperial stout. I’m going to be using 52 lbs of grain and mashing with 16 gal of water. It just makes sense to upgrade for $60 as opposed to several hundred without losing quality.
First time I heard about the 4-8" myth…
Naturally you will lose efficiency when you brew high gravity imperial strength beers. Most cases due to “under” sparging due to fixed kettle size vs grain/total liquor ratio. You may consider continue sparging and running off to a separate kettle, boil it down and add it back to the main kettle to compensate for the “loss” in efficiency or use more grains.
My mash efficiency starts to suffer if I brew beers above 1.070 because I have to stop running off at 29 litres (30L stock pot), leaving behind sugar in the grain bed.
The only reason I can think of the shape affecting efficiency is in the lautering and running off than the actual mash itself. I run off slowly because i’m basically drawing from one end of the cooler box with a bazooka. If I run off too fast, then the wort will just fine the way of the least resistance and there will be alot of sugars in the grain bed left un-rinsed. So consider the shape of the mashtun and the speed you are running off, the channelling of the wort, and if you are drawing from a specific point in the mashtun or from the centre… etc. No such problems if you batch sparge tho!