Mashing 21 lbs of grain in a 15 gallon pot

[Beer-lord]

I'm going to do my first 10-11 gallon batch in my 15 gallon pot on Monday and all the calculators show I need about 14.5 gallons of water for a 10.5 gallon batch. With that much grain, it will surely overflow so I'm thinking I'll have to do with less water and some sparging. I'm concerned about efficiency though. These same calculators say I need a pot size of 15.5 gallons. But surely is I fill it with 14.5 gallons of water and then add almost 21 lbs of grain the water will rise more than 1 gallon, right?
Is there a tool somewhere that I can put in my pot dimensions and get a better idea?
Beersmith has not always been so accurate and I'm positive I have everything correct for my equipment. I'm thinking of just using 1 gallon less of mash water and sparging with 1 gallon and the efficiency shouldn't be too bad.

[BigPapaG]

Have you seen this one?

Simple BIAB Calculator

[John Sand]

I don't use BeerSmith or other software, though I do consult Brewer's Friend. I BIAB, and have success using 1.3 quarts per gallon, dunk sparging in a separate pot, and adding the sparged wort as I go. My efficiency has gone up to the point that my last batch was high (only 1 point) on gravity and volume. I just bottled 55 12oz. I'm happy.

[BigPapaG]

Hey, there's an app for that...

Biab App

[Beer-lord]

Have you seen this one?

Simple BIAB Calculator

Yes, I use it but prefer this one which I've pretty much tweaked to my liking. http://www.copycalc.com/bob/BIAB%20Fixed%20Boil%20Off

For this batch, Beersmith is actually very close to the calc I use and usually it's not.

[Beer-lord]

Hey, there's an app for that...

Biab App

LOL, I have that app and it pretty much sucks!

Take some of that back. This time the calc I use, Beersmith and the app are all close. Usually when I brew 6 gallons, there's a heap of difference between them.

[BigPapaG]

Hmmm... [scratches chin and squints menacingly]

Don't ask questions you already have answers to son...

[russki]

I routinely brew 11 gallon batches in my 62 qt eBIAB rig. It's a little tricky, but pretty straightforward. Here's how I do it:

I use 11 gallons of water for my initial mash-in; this leaves plenty of room for 20-some pounds of grain. While this is mashing, I heat up 4 gallons of water in a separate pot to about 165F. After the mash is done, I pull out the basket with the grain bag, slide a Weber grill grate under it, set the basket on top. I use a large coffee cup to "sparge" the grains until I get within about 1/2 gallon of my desired pre-boil volume, then I squeeze the bag to get that last 1/2 gallon. Works perfectly every time; the only difficult part is lifting 50 pounds of wet grain.

Good luck!

[Beer-lord]

Even with 14 lbs of grain on my regular batches the bag is very heavy. However, I've had great luck using a strainer and removing about half the grains out into 2 other bags/buckets and letting them drain as I squeeze. I reclaim a good deal of very sweet liquid and that's why I think my efficiency has always been good.
And, I've pretty much decided that's what I'm going to do.
Thanks for all the tips guys. You know I'll bore you with details when I'm done.

[BigPapaG]

That's a lot of grain man... I have never made a batch that large!

[philm00x]

You can always use a partial boil volume and then top the fermenter off with however much it takes to get to your target fermenting volume. Your preboil and postboil gravities will be higher than calculated, but when you top off with water, it should cancel out and hit your target OG.

[Beer-lord]

I've done 16.25 pounds for a 6 gallon and am glad I'm making a session brew this time or there's no way I could do it in a 15 gallon pot.
We just figured we'd spend a little more time to do 11 gallons and split it in two and then make some changes on the fermentation end to see how they are. I do know they'll be hoppy.
I have a grain bag that can supposedly handle more than 40 lbs though I'm not sure it would last more than a dozen brews that size.
http://www.homebrewtalk.com/f11/biab-po ... st-384445/

[Inkleg]

I'm not at my computer right now, but BeerSmith will tell you total volume needed. Lower right side on the recipe page is a list of things that YOU select to be there. With my equipment profile and grain bill in the recipe it tells me if it will fit or not. I've done 21+ pounds in my 15 gallon pot. My RIS was 22, I held back 2 gallons to sparge with. It was a thick mash with that much grain and efficiency suffered some, but I have beer.

[Inkleg]

What is the OG your are trying to achieve for this recipe?

[Beer-lord]

I have Beersmith info and it's gels with 2 other BIAB calculators. This is a small session beer, OG is expected to be 1.054. I think I am only about 1 or so off for 11 gallons ( I really want 11 due to the loss from so many hops being used). I see no problem with a thicker mash and will likely mash for an extra 15 minutes and do a mashout and a 2 gallon sparge.
Even got my new orange gloves to squeeze the crap out of the bag.