12.5 gallon kettle, max batch size?

Hey all, I picked up a 12.5 gallon steamer / burner combo to move into BIAB. My question is what is the largest recommended batch size you would try with this kettle? According to this calculator, a 10 gallon batch would have a pre boil wort volume of 12.15 gallons. Is that pushing it?

http://www.brew365.com/mash_sparge_water_calculator.php

To answer your question will need to know what your boil off rate is with the new pot. I would assume about 1 gallon an hour. in a 60 min boil having 11 gallons will get you the 10 gallons if you were losing 1 gallon an hour. This is just a guess since I dont know what temp you boil your water or how vigorous you boil.

Have you calculated how much water you will need to start with to include how much the grains will soak up? I get the sense that your egor to get 2 batches going. I was the same way a when I started. Volume over quality!

There is nothing wrong with 2 4 gallon batches, keep that in mind!

Thank you for the reply. I am going to try to determine my boil off rate ahead of time because I read that I should "season" my new aluminum kettle.

I am stepping up from extract brewing, so I don't know much about determining how much water I will need. I am reading and comparing recipes and reading as much as I can on it though.

Honestly my purpose isn't just about quantity, it's also about time constrictions. I only get to brew about once a month, so I'd like to make the most of it. And having twice as much beer in basically the same amount of time appeals to me.

Edit: I have also read a few threads where people are mashing in with like 8 gallons of water, and then topping off to achieve pre volume boil. The results are good for them. That's what I was planning to do if it will work. I'll do 9.5 gallons, I'm easy. I just want to know what everyone thinks is my max.

Topping off is used by many brewers here, myself being one. The only possible problem could be lack of hop utilization, some will say. I have never noticed any difference myself. It works better for me as my back isn't as strong as it once was. That allows me to move the partially filled fermenters to their chamber, and then top off, therefore saving my back.

MindenMan said:

Topping off is used by many brewers here, myself being one. The only possible problem could be lack of hop utilization, some will say. I have never noticed any difference myself. It works better for me as my back isn't as strong as it once was. That allows me to move the partially filled fermenters to their chamber, and then top off, therefore saving my back.

Click to expand...

I was actually talking about topping off before boiling, but I don't see why post boil top off wouldn't work. That's what's done with extract brewing with good results.

https://www.homebrewtalk.com/f244/biab-21-grain-bill-possible-10-gallon-batch-401574/

I have a few threads from when I did the step up from extract to BIAB to All grain this is one of them. You will find that its not that hard to really do and the time factor is really nice. If you add top off water maybe use some more base grain to hit your numbers. All in all enjoy and dont over think it. ^^^ is correct dont worry about hop utilization right now its not that big of a deal.

https://www.homebrewtalk.com/f244/rye-me-river-biab-442558/

heres the other thread.

Check out my BIAB calculator below in my sig. It's new but is pretty accurate and agrees with most calculators I've found.

Like they said I would assume ~1 gallon boil off rate/hour.

Consider sparging for 2-3 Gallons or so and you should be able to do a double batch with a little effort and maybe some fermcap.

pricelessbrewing said:

Check out my BIAB calculator below in my sig. It's new but is pretty accurate and agrees with most calculators I've found.

Like they said I would assume ~1 gallon boil off rate/hour.

Consider sparging for 2-3 Gallons or so and you should be able to do a double batch with a little effort and maybe some fermcap.

Click to expand...

I have a 5 gallon cooler, I was thinking of trying that as well. Complicates the BIAB process, but that's on me.

Your batch size will likely be limited by the target OG, and whether or not you do some kind of sparging. A 10 gal batch of somewhere near 1.060 OG should be manageable if you do a thick mash, sparge, and add make up water later in the boil or to the fermenter. Managing spills and boil overs will require constant vigilance.

For example (based on my experience), 24-25 lbs of grain should give you an OG of ~60 if you get 73-76% efficiency. Mashing 25 lbs @ 1.25 qts/lb (thick for BIAB) would require just under 8 gal of strike water, and the grain plus water would have a volume of about 11.5 gal. After you pull the bag, you would sparge (dunk or pore over bag) to a volume of ~11 gal. I have actually done 14 lbs of grain with 6 gal of strike water in an 8 gal BK sparged to 7-7.25 pre-boil volume. Like I said, you have to be very careful to avoid sloshing during mash in and boil overs.
Brew on
[Edit: changed "thin for BIAB" to "thick for BIAB"

doug293cz said:

Your batch size will likely be limited by the target OG, and whether or not you do some kind of sparging. A 10 gal batch of somewhere near 1.060 OG should be manageable if you do a thick mash, sparge, and add make up water later in the boil or to the fermenter. Managing spills and boil overs will require constant vigilance.

For example (based on my experience), 24-25 lbs of grain should give you an OG of ~60 if you get 73-76% efficiency. Mashing 25 lbs @ 1.25 qts/lb (thin for BIAB) would require just under 8 gal of strike water, and the grain plus water would have a volume of about 11.5 gal. After you pull the bag, you would sparge (dunk or pore over bag) to a volume of ~11 gal. I have actually done 14 lbs of grain with 6 gal of strike water in an 8 gal BK sparged to 7-7.25 pre-boil volume. Like I said, you have to be very careful to avoid sloshing during mash in and boil overs.

Brew on

Click to expand...

Thanks. I'm not stuck on 10 gallon. I guess I'll just try maxing out the kettle and see what happens.