4.5 Gallon pot - how big a boil can I go?

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mattd2

mattd2

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Ok so I am looking to get out of Cooper's kit and kilo no boil kits finally, they have been great to get me started and I have progress a little to modify some (i.e. Tucan method with no sugar) but I want to move further along with the whole process. Now comes my issue - Money (isn't this everybody's problem;))
I have found a pretty cheap pot from what is our walmart type of store, about US$20 for a 17.1 litre (~4.5 G) with metal lid. looking at doing BIAB with a bag sparge and aiming for 3 gallons into the fermenter. Boil will be done on my stove (if it can handle it!) so I estimate between 0.5-1 gallon boil off over an hour gives me a 3.5 - 4 G boil sizes. Now in your guys opinoins is allowing 0.5 G head space (term?) in a 4.5 G pot asking for trouble? I planned to stand over it for the whole hour boil, water spray bottle in hand to fight off any potential boil overs?
I know I could do extracts with top off water but with the price of extract over here my yearly brewing budget would be blown in 1 batch (ok not that bad but still pretty crazy).
I estimate I could make 3 gallons of all grain for the same price as 6 gallons of kit & kilo, I am fine with brewing more and have had SWMBO's sign off on that!
So really my overall question is can I do 3 gallon batches in a 4.5 gallon pot?
 
I think you can do 4 gallons if you're very diligent watching for boil-overs. However, that's 4 gallons total volume. If you fill the pot with 4 gallons of water, then add several pounds of LME, and then a pound of steeping grains, you're going to be in trouble.
 
Thanks, yeah I was refering to 4 gallons total boil volume after everything has been added. Going all grain with the BIAB method so no LME is needed (unless I mess something up royally!)
 
Get some fermcap-s anti foaming liquid. 3-4 drops/per gallon will prevent boil overs. I have one of those 5 gallon pots for stovetop brewing that only really holds between 4 and 4.5 gallons. I've managed to push it to about 4.25 gallons in the kettle on the stove, get a good boil going, and take a nap between hop additions.

I do more than half my annual brewing as 2.5-3 gallon stovetop allgrain test batches, and that pot works great. You need to figure out your boiloff rate for your stove. In an hour if you boil down 1 gallon, then you can do a 3 gallon batch.
 
Yeah, so I haven't done BIAB before, but just thinking about the logistics... For a 3 gallon batch, you're going to have something like 7 lb of grain (depending on the recipe, obviously). The "can I mash it" calculator here: http://www.rackers.org/calcs.shtml says that 7lb of grain with 2qt/lb gives you 4 gallons total volume. 7 lbs of grain is gonna absorb around a gallon of liquid, so you're gonna get around 2.5 gallons left in the kettle (7lb * 2 qt/lb = 14 qt / 4 = 3.5 gal - 1 gallon for absorbtion = 2.5 gallons). So if you then bag sparge with 1.5 gallons of water, you should hit your 4 gallon volume.

Seems do-able to me.
 
Thanks Revvy,
Yeah I have done some very rough maths to determine boil off now, basically the stove is on a 25 amp 230 v circuit so that gives it a maximum power of 5.75kW (tested by trun on all elements and the stove circuit braker doesn't trip). that is split between 2 big and 2 small elements so I assumed about 1.9kW for a big element. With the heat of vapourization being 2260 kJ/kg this gives a boil off of about 0.8 gallon an hour (assuming 100% efficient which it will not be)
 
jaobrien6 said:
Yeah, so I haven't done BIAB before, but just thinking about the logistics... For a 3 gallon batch, you're going to have something like 7 lb of grain (depending on the recipe, obviously). The "can I mash it" calculator here: http://www.rackers.org/calcs.shtml says that 7lb of grain with 2qt/lb gives you 4 gallons total volume. 7 lbs of grain is gonna absorb around a gallon of liquid, so you're gonna get around 2.5 gallons left in the kettle (7lb * 2 qt/lb = 14 qt / 4 = 3.5 gal - 1 gallon for absorbtion = 2.5 gallons). So if you then bag sparge with 1.5 gallons of water, you should hit your 4 gallon volume.

Seems do-able to me.
Click to expand...

Sweet so from the comments so far, I can mash it and I can boil it (depending on if my stove can handle it!)
AG here I come (after next pay day ofcoarse!)
Cheers :mug:
 
mattd2 said:
Sweet so from the comments so far, I can mash it and I can boil it (depending on if my stove can handle it!)
AG here I come (after next pay day ofcoarse!)
Cheers :mug:
Click to expand...

And FWIW, you might know this already, but I only picked 2 qt/lb because I was curious what the maximum water you could fit with 7 lbs of grain was. A traditional mash would be more like 1.25 to 1.5 qt/lb and then use more sparge water. I don't know about BIAB though.
 
jaobrien6 said:
And FWIW, you might know this already, but I only picked 2 qt/lb because I was curious what the maximum water you could fit with 7 lbs of grain was. A traditional mash would be more like 1.25 to 1.5 qt/lb and then use more sparge water. I don't know about BIAB though.
Click to expand...

Yeah I was wondering where that 2 qt/lb came from, I'm not 100% sure on the split for BIAB with a sparge as the OG method was just adding all the water at the start, bit of trial and error might be needed, or more reading!
 
Just to add a twist and tempt you, you can actually brew 5 gallons in a 4.5 gallon pot. Overshoot gravity w/ a large grain bill, adjust hops (add more to account for the sg of the wort) and a gallon of chilled water post boil to the fermenter. Magic huh.
 
wilserbrewer said:
Just to add a twist and tempt you, you can actually brew 5 gallons in a 4.5 gallon pot. Overshoot gravity w/ a large grain bill, adjust hops (add more to account for the sg of the wort) and a gallon of chilled water post boil to the fermenter. Magic huh.
Click to expand...

Would this yeild worse efficiency though (thinking in terms of what I have read about brewing big beers)?
 
Cool, might look into it. I'll try a 3 gallon first to work out a rough eff. then after a couple of small batches try a 5 gallon to see how much eff. is hurt. Thanks :mug:
 
So yesterday I picked up my 4.5G pot for, with the current NZ-US exchange rate, US$12 !!! It does seem like a $12 pot though, very thin walled but it'll do for a start.
Also picked up a voile curtain as it was 40% off = US$5 to make the grain bag out of. Might have stuffed that up a bit as I went for one with a approx 1 mm square hole size, which might be to big? nayone have thoughts on this? I will double it over and stitch it so that the grain will have to go through 2 "bags" to get out!
Also picked up 3 kg of UK pale malt, 1 lb of sticklbrack (sp?) hops and some US-05 yeast. I will do a simple smash beer to get my head around this BIAB without to many more things to remember (like which is the right hops to add now!)
So tonight I will be stitching the bag (nylon fishing line thread - good/bad idea?), checking the boil off on the stove and planing the recipe (I'm am thinking 2.5 - 3 G post boil with maybe 4.4 lbs malt and 2 oz total hops).
I'll try remember the camera so I can document the progress.
On a side note, me and SWMBO are now trying for our 3rd child and when she realised that all this work was for my progression into making beer from scratch she was a bit annoyed as she wouldn't get to try my first AG with everyone else, I made up for it by planning to keep 4 bottles of each brew from now until after the new baby arrives then we can go through in one night and try all my AG from start to finish. I said it would be an awesome thing for me as well because it means I will keep those 4 beers and in 10+ months be able to track through my progress with her!
 
mattd2 said:
So yesterday I picked up my 4.5G pot for, with the current NZ-US exchange rate, US$12 !!! It does seem like a $12 pot though, very thin walled but it'll do for a start.
Also picked up a voile curtain as it was 40% off = US$5 to make the grain bag out of. Might have stuffed that up a bit as I went for one with a approx 1 mm square hole size, which might be to big? nayone have thoughts on this? I will double it over and stitch it so that the grain will have to go through 2 "bags" to get out!
Also picked up 3 kg of UK pale malt, 1 lb of sticklbrack (sp?) hops and some US-05 yeast. I will do a simple smash beer to get my head around this BIAB without to many more things to remember (like which is the right hops to add now!)
So tonight I will be stitching the bag (nylon fishing line thread - good/bad idea?), checking the boil off on the stove and planing the recipe (I'm am thinking 2.5 - 3 G post boil with maybe 4.4 lbs malt and 2 oz total hops).
I'll try remember the camera so I can document the progress.
On a side note, me and SWMBO are now trying for our 3rd child and when she realised that all this work was for my progression into making beer from scratch she was a bit annoyed as she wouldn't get to try my first AG with everyone else, I made up for it by planning to keep 4 bottles of each brew from now until after the new baby arrives then we can go through in one night and try all my AG from start to finish. I said it would be an awesome thing for me as well because it means I will keep those 4 beers and in 10+ months be able to track through my progress with her!
Click to expand...

so how did this go? pics?
 

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