I will be attempting my first all grain batch soon. I’ve got a 48qt rectangular Rubbermaid cooler MLT that I made w/ a stainless steel braid. For a couple of reasons, I’m thinking of doing a 3 gallon batches. Would the 48qt cooler MLT that I have now too big for a 3 gallon batch? Thanks!
You’ll lose more heat than if it were a 5 gallon cooler, but I don’t think it will be a problem. Maybe just mash a little higher to account for some loss in heat.
Not too big, I wouldn’t think. You might get more cooling than with a larger mash. I’ve done small mashes in a large cooler but not for a while. Now I do BIAB for 3 gallon batches. It’s easier that using a MLT. Efficiency suffers. No big deal. I compensate by using slightly more grain.
+1 to both above. just last weekend I mashed 7 lb of grain in a 72 qt cooler and had 0 problems. I always heat my strike water to ~5 degrees hotter than beersmith recommends, pour it in and close the lid for a few minutes to ‘preheat’ the tun then stir in the grain.
Why does your efficiency suffer? If you mash at 2qt/lb, then add more water and drain, you should get 75%.
I may have to try this next time. I have a similar sized cooler that I’ve nailed the temps using Beersmith, but seems like more often than not my temps settle lower than expected. Last weekend, I preheated the cooler because it was about 40* in the garage. I followed the Beersmith amounts and temps for a triple decoction and was 5-10 degrees cool on all three steps… >:(
it won’t be a problem. you will find ways to compensate. i brew small batches and the next one will actually be a modified biab, actually mash in a bag. i have a 22 quart electric roaster oven that i intend to mash in. lift the grain bag out and rinse it over a grate, then crank up the heat to boil.
dave R. do you bottle or keg. i have been playing with different ways of kegging 1-3 gallon brews and haven’t found a perfect fit yet
I’ve brewed 3-gallon batches for many years. I’ve discovered that when mashing less than 6.1 lbs grain, the stainless hose doesn’t get covered by the grain so it sucks air and doesn’t run off very well. So for those batches I just use BIAB. For batches with more than 6.1 lbs grain, I can use my rectangular cooler as normal. In either case, I get almost identical efficiencies averaging in the mid-80s, so the mash method really has no effect.
Thanks everyone. I’ll definitely take your advice and increase my mash in temp by about 5 degrees or so and make sure that I preheat the cooler before starting the mash. I’ve got a T tree connecting both ends of my stainless braid, so hopefully that keeps it from floating up too much. BIAB is intruiging, but I do plan on doing 5+ gallon batches also, so I figured a couple of three gallon batches would be good practice to get my system down before moving onto bigger batches.
I use a 20 gallon cooler for my 3 gallon batches, so the geometry is different, but this shouldn’t be a problem if you use a dip tube so that the braid is entirely on the bottom of the cooler.
Nothing wrong with kegging 3 gallons in a 5 gallon keg. I do it all the time since I brew 3 gallon batches exclusively.
I thought it was an unwritten home brew rule that a keg MUST be filled. 
My rule is that a full keg must be emptied. In progressive installments of 12 to 16 ounces.
Sure, whatever fills your sail with wind, brutha.
Thanks for the input everyone, it really helped out. Completed my first all grain batch last weekend and it’s been fermenting well for the last week. Brewed up a Breckenridge Christmas Ale clone, so larger gain bill than a normal 3 gallon batch. Heated my strike water to 168 and poured it into the cooler and let it sit for about 5 minutes to heat up the cooler. Got to a mash temp of 154 after stirring in the grains and only lost 2-3 degrees during the hour mash. I also covered up the cooler with an old comforter to help keep the heat in. Did the vorlauf and drained into the brew pot. Batch sparged w/ 175 degree water, vorlauf, and completed runoff which got me to just under 4.5 gallons of wort. At 1.074, I just missed my OG of 1.078, but I can live with that.
If you have a consistent undershoot you can scale up the base malt by a quarter pound or so or add a little light DME.
its not so much that i wouldn’t put 3 gal in 5 gal keg. it is the room of a 5 gal keg if i am only brewing 1-2.5 gallon batches. i have nearly worked out a way of kegging in 1 gallon apple juice bottles and still like the tap systems i have seen people make for the 5l kegs. my new thought though is using the 2 gallon/8liter hdpe spray tanks for chemicals. still playing.
Just bottle it at that point dude. 3 gallon kegs are expensive, but I really want one. Could put it on the hump in my serving chest freezer.
I bought a Tap-A-Draft system and have not regretted it. Very simple, space-conscious kegging alternative. We have a humongous fridge, so that helps, but the PET bottles that come with it are very compact. From a 3-gallon batch, I filled one Tap-A-Draft and bottled the remainder for give-aways.
I also use a Tap-a-draft for small batches, the only problems being that they require natural carbonation, so you have to be careful not to move them or you will get yeasty beer, and the pressure varies depending on how much CO2 is left in the canister.
The Tap-a-draft would be improved if someone sold a carbonator cap for these larger bottles and an adapter for a paintball CO2 tank to connect to the tap head.