BeerBorg

Ok...let's say I want to do an all grain batch that is 2 gallons after the boil...

if I want to use a rectangular cooler as a mash tun, what size would be best? I think palmer said that if your grain bed is not deep enough that your efficiency will suffer.

Would a 5 gallon cylindrical cooler be better?

assume 5 lbs of grain for the mash.

if I was doing brew in a bag, would a 5 gallon pot be large enough for the mash ( about 3 gallons water + 5 lbs of grain? )

thanks for help in advance.

I think most people find the cylindrical coolers to be the best option, but a rectangular cooler would work just fine. If you already own an appropriate-sized rectangular cooler, then it would be cost effective to just convert that. But, if you have to purchase a cooler anyway, then I would recommend the cylindrical type. The best size really depends on what you plan to brew; low, medium, or high gravity brews.



Generally speaking, your kettle should be about twice the size of your batch size (final volume) for BIABs. I do use my 22-quart kettle for 3-gallon batches and my 44-quart kettle for 6-gallon batches. Again, it will depend on your recipe gravity.

I have a 5-gallon cylindrical cooler mash tun, and while I know I could use it for my 2.5 gallon AG batches, I prefer not to. That's just my personal choice, mostly because I don't want to have to clean it every week. So I do my fivers in it, and do BIAB for my smaller batches.

I have a five-gallon pot and a three-gallon pot, and while it seems to defy logic, I use the smaller pot for my mash and the larger one for the sparge. This is because I learned quickly that about half the mash water gets absorbed by the grain, whereas the sparge water doesn't. Thus, overflow is likely if I add that much wet grain volume to the smaller pot.

I have to question your numbers on your BIAB example, though. Three gallons of water to 5 pounds of grain seems a little high. Usually the ratio is 1.25 quarts per pound. At the most, 1.5 quarts. For five pounds of grain, the most you'd want to use for a mash is about 1.8 gallons. Make up the pre-boil volume difference in the sparge.

I have used up to 7 lbs of grain in my 5-gallon cooler mash tun with no problems. I actually think I can fit even a couple lbs more in there before my efficiency starts to suffer. I make 2.5 gallon batches with it at a ratio of 1.5-1.75 quarts per lb (unless it's a strong Belgian ale where I'll follow the default suggested ratio from BeerSmith at 1.25 qt/lb).

I regularly use 7 pounds+ grains in my 5 gallon tun. No biggie, and I usually get around 75%efficiency. I almost always use 1.25 quarts per pound. Nothing to it.

Edited to add:

Not that 7 pounds of grain is the upper limit, either. Sunday, I brewed a batch of Pearly Pils, which requires 11 pounds of grain. Not even close to reaching the top.

I did 12 lbs in my 5 gallon round yesterday. I cut the water to 1.125 quarts/lb and had about 4 inches of room to the top.