So is a 10 gal kettle not big enough for 5 gallon batches? I generally don't go above 1.049(with the exception of one 1.083 once a year). Have I actually screwed the pooch on grabbing a tall boy 10 gal pot?
I was hoping to go for the no sparge method stickied here. It listed a 10 gallon pot as big enough. Thats what I went for....
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The biggest beer Im going to be using is 16.5lb grain but average is under 10lbs. If that makes a difference
Ok, lets look at the numbers using this mash tun vol calculator.
http://www.haandbryg.dk/mashcalc.html#mash
16.5 lbs of grain mashed at 2 qt/lb (33 qt (8.25 gal strike water) results in a total mash volume of 9.6 quarts, check OK
Loss due due grain absorption will be approx .1 gal / lb grain or 1.6 gallons, so your wort volume after removing the bag will approx. be 8.25 gal minus 1.6 gal equals a preboil volume of 6.65, boil off a gallon and your finished wort volume will be 5.65, check OK
Tips....mashing in with a total volume of 9.6 gallons of mash in a 10 gallon kettle might be tricky and lead to spillage, so you could hold back a gallon and add that after the mash rest.
With a sparge step, you could mash 20 lbs without issue IMO..
I think you have made a fine choice with the 10 gallon considering your main objective of brewing moderate gravity brews, especially if stovetopping where a larger kettle will require more heat to boil, and have space constraints. Considering most of your batches will only be 10-12 lbs of grain, the 10 gallon is an appropriate size. I feel one is better served to have the right size kettle for 90% of their brews, and a little small for 10%, rather than too large for 90%, and just right for 10%.
The smaller 10 gal will also hold temp better having less head space and surface area than the larger kettle, the 10 gal may fit in your oven as well, which is a very easy and effective way to maintain steady mash temps. Might want to consider trying some fermcap S, or infant gas drops (simethicone) till you get the hang of bringing to a boil without a boil over.
Hope this helps.
wilser