How to calculate water amounts for BIAB... Confused as hell

[r8rphan]

So, with my prior system, I used the "brew target" program to calculate recipes, and it was pretty straight forward... For the mash, I just entered the amount of water that the cooler would hold with the lid on in the equipment profile, and went from there.. I could play with the qt's per pound (with 1.25 qt. per pound being ideal) t make everything fit in my not that big mash tun...

But now, I have a vessel that has water space under the false bottom/grain bag, and I'm not sure if I need to consider that as part of the strike water or what.....

My new system holds about 4 gallons of water under the grains, with a max capacity of 14 gallons (leaving one inch to the rim of the keggle, which I'd rather not cut it that close), meaning there is up to 10g available for the area where the grains will be..

Am I supposed to enter the total amount of liquid the whole vessel will hold or just the amount from the false bottom up or what? And how do I figure out how much water to heat up before adding grains so that I don't have to worry about running our of room (overflow) when I add the grains, yet still have enough to do the mash?

Also, how many pounds per gallon do the grains take up in as far as volume goes, so that I know how much water the keggle can hold with the grains in there?

Here is a typical recipe and mash schedule with my old system, as well as a typical equipment profile for the same system...

 

[r8rphan]

I found this CALCULATOR

Third one down "Can I Mash This?", which I think is implying that the water below the grain (under the false bottom) is not counted as part of the 1 to 1.5 qt per pound mash in amount...

So that means I actually have a 10 Gallon Mash Tun, which is slightly smaller than my last one...

So for a 25 lb grain bill, at 1 qt per lb I will need 8.35 gallons of space for the mash itself, which means My keggle will be 12.25 Gallons full... That's doable...

At 1.25 qt per lb I will need 9.81 Gallons of mash space, which puts the total keggle volume at just under 14 Gallons..

That's tight... If I go with a larger grain bill than that, I will have to thicken the mash.. at 1 qt per lb, that maxes me out at just over 30 lbs.. I guess the solution when I get into that range, is to go for less beer to reduce the grain bill... (ie 9 G instead of 10-11 G, etc.)

Really, pretty much everything I would do should be able to be done at full volume and 1.25 qts per lb... providing I can get decent efficiency from my system


Now I just gotta figure out how to take this information and subtract the grain with absorption from it to determine actual strike volume...

 

[r8rphan]

I think I'm having a brain fart and over complicating this... or not...

Did the calculator tell me all I need to know?.. That it will hold my mash, and I just need to start with how much water it tells me plus the 4 gallons under the false bottom?...

Seems like that would just make it all overflow... Do the spaces between the grain, really take up all that water, So that it is pretty much the same whether the grain is in there or not?

 

[r8rphan]

DOH!

I just multiply the mash thickness times the grain in lbs and divide by 4!

So, with a 25lb grain bill, I would multiply 25 x 1.25 and divide the result by 4... Add that to my 4 gallons under the false bottom and viola! Right (I hope)?

So, 25 x 1.25 / 4 = 7.8125 Gallons + 4 gallons = 11.8 gallons...

So, I treat then heat 11.75 Gallons of water, add my grains, and the whole thing should bring the liquid level to just under 14 gallons?

Basically, adding the 25 lbs of grain will only cause about a 2 Gallon rise in level?

Does this seem right?

Am I on track now? If I do that will my keggle not overfill?

 

[r8rphan]

And, from what I am reading, the grain absorbs somewhere between .1 and .13 qts per pound, so when I remove the spent grains and let them drain into the keggle, I can expect there to be about .625 - .8 gallons less in the keggle than I started with?

So I start with 11.75 gallons of water, add grains, and end up with about 11 gallons of wort..

If this is an 11 gallon recipe, then I add 2 more gallons of water (possibly as a sparge of some kind), to get to my 13 gallon pre boil volume...

Check my gravity, adjust the recipe (boiling volume down, or adding water, or even changing batch size and hops amounts) if the efficiency was different than I was shooting for? (Actually, I guess I should check and adjust that before adding makeup/sparge water)...

Have I got all this right?

 

[r8rphan]

It's all starting to come back to me now!

Thanks for all your help!

:smack::beard::rockin::fro::cross:

 

[Bobby_M]

Absorption ratios vary quite a bit for static lauter tuns and BIAB. The .1 gallons per pound is a lauter tun rule of thumb. In BIAB, it's more like .06 or even .04 if you really squeeze the bag.

 

[shetc]

I've had very good results using the BIABacus at http://www.biabrewer.info/viewtopic.php?f=10&t=1869

 

[r8rphan]

I've had very good results using the BIABacus at http://www.biabrewer.info/viewtopic.php?f=10&t=1869

HA! What a great name for the calculator!

 

[r8rphan]

When are they expecting to release it?

 

[casualbrewer]

Precisely why I do full volume no sparge. Very easy to predict with most grain bills. Grain absorption for me is about .05 as. Squeeze heavily.

 

[nutty_gnome]

My absorption ratio is generally 0.6 - 0.75 depending on grain bill. I do a full volume mash and usually start with 7 - 8 gallons depending on how much grain I use.

 

[soccerdad]

have you tried this calc?

https://pricelessbrewing.github.io/BiabCalc/

 

[r8rphan]

Precisely why I do full volume no sparge. Very easy to predict with most grain bills. Grain absorption for me is about .05 as. Squeeze heavily.

What kind of efficiency are you guys getting with the no sparge method? Do you recirc, or just soak and stir? Are you treating your water?

 

[casualbrewer]

What kind of efficiency are you guys getting with the no sparge method? Do you recirc, or just soak and stir? Are you treating your water?

Right at 80% plus or minus a couple percent at times. I just mash in and stir often. And yes I treat my water... More so just for pH but I do add a little bit of minerals.

 

[r8rphan]

Right at 80% plus or minus a couple percent at times. I just mash in and stir often. And yes I treat my water... More so just for pH but I do add a little bit of minerals.

Awesome.. If I can hit 80% without sparging, I'll be stoked... That will make my kettle big enough for pretty much any beer I want to tackle...

 

[soccerdad]

If I were starting out with BIAB, and still dialing in my grain crush, I would start estimating 70 to 75% conversion. With the right crush and a good water volume calculation 75% will be a min and you are likely to experience 80% or better. As far as water calcs, I agree with casualbrewer, the primary objective is to get ph in line. There are two good calcs for this - one at brewersfriend and bru'nwater. There is also an ez water calc, but I have no experience with it so I can't say. There is a thread here at HBT on it.

 

[shetc]

I think the assumed efficiency of the BIABacus is 84% but I need to go back and check.

 

[Johow]

I use Brewers friend which has settings for BIAB. It'll give the total water needed based on my recipe and my brew equipment (completely editable) profile. That amount will not usually fit in my kettle with all the grain so I just subtract 2 to 2 1/2 gallons, do my mash and then use the rest of the water to do a pour over sparge. Brewers friend will also give your boil volume so I just sparge till I collect that volume and then boil. Ez-peazy and repeatable.

 

[1MadScientist]

The BIABacus tells you all your volumes with no calculations. Go sign up and grab a copy now.

The BIABacus is the only software that adjusts efficiency based on all other parameters.

 

[Mer-man]

Another vote here for Biabacus. There will never be a final version apparently, but I donated anyway because it's good.
The only things you need to adjust for are your grain absorption, kettle thickness, and grain extract potential. And maybe not that last one, but for me my local grains are not amazing.

 

[soccerdad]

I agree that BIABacuc is a superb calculator. I am a bit stupid with it as I do not run Excel and am only partly literate in spreadsheet. Hence my greater use of brewersfriend - works for dumbos like me. But if you have Excel and are spreadsheet savvy, BIABacus may be the best out there.

 

[h22lude]

The best thing to do is run a batch or two and take great notes on volume. This is the best way to set up your system.

You'll need boil off, grain absorption, loss to trub in fermentor and loss to kettle and chiller. Boil off is easy, boil for 30 minutes and multiple by 2. Grain absorption you will need to take your mash in volume remove the grain and take your pre boil volume. Loss to trub in fermentor is just that, what is left from bottling or kegging. Loss to kettle and chiller is what is left over in your kettle and chiller (if using CFC or plate chiller) after transferring to primary.

Once you have those, you can easily calculate your volumes working backwards. It is good to do this along with using a calculator to double check everything. Take bottle volume, add loss to trub in fermentor to get batch size. Take batch size plus loss to kettle and chiller to get post boil volume. Take that plus boil off to get pre boil volume. Take that plus grain absorption to get strike water.

For software, I really like BeerSmith. I have set my system up and can easily calculate volume and gravity. I can also enter in someone else's recipe and have it adjusted to my efficiency and batch size with the click of a button.

 

[petrolSpice]

I ended up making my own calculator in Excel that fits my specific process of BIAB. I've tried many calculators and wasn't completely satisfied with any of them.

The biggest gripe I had was including corrections. For example, if my mash efficiency was low I have an area to add DME. Too high and I can add water and it will recalculate everything for me. I can perform these corrections after mash, after boil, and after pouring into the fermenter to ensure I hit my targets.

I've done ~10 BIAB batches and am still changing and dialing in my process. The hardest part by far is volumes, and I'm often pretty far off from my estimates. Or my measuring techniques suck.

 

[h22lude]

I ended up making my own calculator in Excel that fits my specific process of BIAB. I've tried many calculators and wasn't completely satisfied with any of them.

The biggest gripe I had was including corrections. For example, if my mash efficiency was low I have an area to add DME. Too high and I can add water and it will recalculate everything for me. I can perform these corrections after mash, after boil, and after pouring into the fermenter to ensure I hit my targets.

I've done ~10 BIAB batches and am still changing and dialing in my process. The hardest part by far is volumes, and I'm often pretty far off from my estimates. Or my measuring techniques suck.

I love using Excel and creating my own stuff but you may want to check out Beersmith. This program does all that already. Convert other recipes to your system. Figure out how much dme or water you need for correction. Plus a lot more features.

 

[petrolSpice]

I love using Excel and creating my own stuff but you may want to check out Beersmith. This program does all that already. Convert other recipes to your system. Figure out how much dme or water you need for correction. Plus a lot more features.

I've only messed around the Beersmith a little bit, but corrections aren't as streamlined as I'd like. I also don't see an easy way to correct gravity by adding DME or other sugars. Mine will compute the corrections to get me back on target.

Beersmith is amazing, but 90% of it I don't have use for.

 

[h22lude]

I've only messed around the Beersmith a little bit, but corrections aren't as streamlined as I'd like. I also don't see an easy way to correct gravity by adding DME or other sugars. Mine will compute the corrections to get me back on target.

Beersmith is amazing, but 90% of it I don't have use for.

What type of corrections you looking for?

To adjust the gravity on the fly like you want, in BeerSmith you simply go to Tools and Adjust Gravity. You enter your gravity, volume and what you want the gravity to be. It tells you how much DME or water to add. Can't get much simpler than that.