BIAB Water Volume Calculator

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jbrookeiv

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Hey guys,

I put together a BIAB Water Volume Calculator to help on my brew days, and figured I'd share it with you. I always seemed to forget to do the calculation before heading to my buddy's to brew, so I finally got it posted on my blog. Enjoy!

http://classist.net/biab-calculator

Please consider donating using the embedded Donate button on the page if you find the tool useful.
 
Figured I'd bump this in case anyone missed it. I think it's a very useful tool for all of you BIAB brewers out there.
 
Hey man, just saw this will be putting it to use this weekend on my first all grain. I'm going to use a cooler for mashing. Quick question for strike temp, do you just go a couple deg higher than your mash temp since you are using such a high water to grain ratio?
 
ksparkes said:
Hey man, just saw this will be putting it to use this weekend on my first all grain. I'm going to use a cooler for mashing. Quick question for strike temp, do you just go a couple deg higher than your mash temp since you are using such a high water to grain ratio?

Yup, usually 3-4 degrees higher does the trick, but I can direct fire my mash since I mash in my kettle, so it's no big deal if I undershoot it.
 
I started out with a grain lb multiplier of .125 like you have in your calculator but it seemed to leave me with too much water. I have only done a few batches.

How many BIAB batches have you done? Has this constant held up pretty good for you? Is it linear or does it seem to absorb more as you get higher OG, requiring 15lb+?
 
Thanks jbrookeiv!! I have been thinking of doing some small all grain batches and this is just what I was looking for :rockin:
 
BIAB absorption varies greatly due to how people handle the bag at the end of the mash. Letting the bag drip out means less absorption, and squeezing the hell out of it even less. I seem to be able to get it down to about 0.05 gal/lb if I squeeze the hell out of the bag when I'm done.
 
BIAB absorption varies greatly due to how people handle the bag at the end of the mash. Letting the bag drip out means less absorption, and squeezing the hell out of it even less. I seem to be able to get it down to about 0.05 gal/lb if I squeeze the hell out of the bag when I'm done.

any problems with squeezing the hell out of the bag? .. I'd like to do that but I'm still scared to try it I guess ... I gave mine a very small squeez last time but I know I left some sugar in that bag ... thoughts?
 
If you use the calculator keep in mind two things:

1. Evaporation rates are extremely variable and are set-up and operator dependent.
2. The water absorption rate will also vary with the same factors mentioned.

So the volume numbers could be fairly off depending on both of these things.
 
If you use the calculator keep in mind two things:

1. Evaporation rates are extremely variable and are set-up and operator dependent.
2. The water absorption rate will also vary with the same factors mentioned.

So the volume numbers could be fairly off depending on both of these things.

Indeed. You can always change the numbers to fit your setup.
 
If you use the calculator keep in mind two things:

1. Evaporation rates are extremely variable and are set-up and operator dependent.
2. The water absorption rate will also vary with the same factors mentioned.

So the volume numbers could be fairly off depending on both of these things.

Two other considerations also...

1. Trub loss
2. Cooling/Equipment loss

The latter is huge for me (upwards of 1.25g) since I recirculate and use a CFC. I think I am going to make my own verison of this and factor those elements in.

Thanks for this!

John
 
Here is what I came up with:

BIABWaterVolumeCalculator.jpg


I have attached the XLSX if anyone wants to play with it. I had to name it as a PDF to be able to attach it here. Just download it and change the extension back to .XLSX.

BTW...not trying to steal anyone's thunder. I just saw some gaps that I know would impact my volumes.

FYI...each item on the left will produce a tool tip if you click on the cell:

tooltip.jpg


I am open to all/any feedback! :)

John

View attachment BIAB Water Volume Calculator - Copy.PDF
 
Hi johnodon,

That calculator is nice and could be handy to use. I have a question regarding your Grain Absorption value. I have read that the normal grain absorption value is 0.125 gal/lb.

In your example, is the 0.075 gal/lb number you use based on after squeezing the grain bag or before?

Thanks,
Trip
:mug:
 
Hi johnodon,

That calculator is nice and could be handy to use. I have a question regarding your Grain Absorption value. I have read that the normal grain absorption value is 0.125 gal/lb.

In your example, is the 0.075 gal/lb number you use based on after squeezing the grain bag or before?

Thanks,
Trip
:mug:

that should be based on squeezing.. if you squeeze REAL hard you can lower that to .050
 
thread resurrection. I have heard no problems with squeezing. I plan on squeezing tomorrow when I do my first all grain batch using BIAB
 
it would be close. the calculator here uses an absorption number that includes squeezing the grain bag. if you did a no sparge and either added a little extra or figure out a way to squeeze the grains to get the wort out then it should be fine.
 
I have a problem understanding how the strike volume can be a factor of the trub/equipment/cooling loss. Won't that impact the gravity? If I'm going to lose 2 gallons from leaving it in the pot or on the equipment don't I need to make up for it with water AND grain?
 
I have a problem understanding how the strike volume can be a factor of the trub/equipment/cooling loss. Won't that impact the gravity? If I'm going to lose 2 gallons from leaving it in the pot or on the equipment don't I need to make up for it with water AND grain?


regardless if you BIAB or do a traditional 3 vessel all grain brew you still have to account for losses in trub, equipment, cooling, boil off. With a traditional mash you don't add extra water and grain, you simply account for it by making sure you have enough in the boil kettle after sparging. with BIAB normally there is no sparge (although some do a dunk sparge). By taking into account all losses upfront you can end up with the desired batch size into the primary. the gravity from my experience doesn't take a hit at all. if you use brewing software like beersmith, when setting up your equipment you enter loss amounts. the software then takes that into consideration when making a recipe. Beersmith v2 even has BIAB settings that take all this into account as well. so far it's been pretty close to the amounts I arrive at using the manual methods.
 
With BIAB, the more water you have at strike the better your efficiency, so your goal is to get as mch water into your pot as possible, thus we work out what losses you will get and add them all up, plus your end of boil volume (or into fermenter volume if you use a kettle loss) and that is your strike.

Theoretically you can then determine a grain bill.

I get 83% Into Boil efficiency with a 1.050 beer using full volume no sparge biab

Increased evaporation will thus increase your efficiency. The efficiency loss is almost 100% due to grain absorption, so reducing this is key
 
regardless if you BIAB or do a traditional 3 vessel all grain brew you still have to account for losses in trub, equipment, cooling, boil off. With a traditional mash you don't add extra water and grain, you simply account for it by making sure you have enough in the boil kettle after sparging. with BIAB normally there is no sparge (although some do a dunk sparge). By taking into account all losses upfront you can end up with the desired batch size into the primary. the gravity from my experience doesn't take a hit at all. if you use brewing software like beersmith, when setting up your equipment you enter loss amounts. the software then takes that into consideration when making a recipe. Beersmith v2 even has BIAB settings that take all this into account as well. so far it's been pretty close to the amounts I arrive at using the manual methods.

But you can only control gravity with the efficiency of the mash and then the boil. If X amount of grain in Y amount of water yield Z gravity after the boil, adding more water up front will yield a lower gravity unless you increase the efficiency. This may be where you make it up, but it isn't guaranteed. The boil gravity is not impacted by after the boil loss. And maybe, the loss isn't nearly as great as the 2 gallon example. For my brews, if I lose a quart that's a lot. That's easily accounted for, except I'm doing extract to this point where you don't have a lot of trub.

You can take the loss into account, but to reach gravity AND quantity you'll need to adjust both water and grain. My guess is Beersmith does that, although I've never looked at it, or any other calculator other than this one.

The other factor though is that the beer will be pretty tasty anyway. I'm usually pretty content with however it turns out. And if you already have some homebrew on hand while you're doing this it won't matter to you.:drunk:
 
Awesome thread and I can't get the calculator to work I Ned help and want to brew today.

Ques. Water vol needed for final 3 gallon batch with grain bill of 9.75 pounds ?? No sparge method, I'm shooting for 70 percent eff. My rough guess would be 3.65 gallons so would be better to round up to 4 gallons.

Another question I'm planning to mix my mash in a cooler with a bag so what would the strike temp be 155??? So I will shoot ten degrees higher? Is this correct ?

Any help would be appreciated the grains are already crushed and waiting
 
do the math... desired batch + absorption + boil off + trub loss. if you use lbs * .072 you'll get an absorption of .702 gallons of water lost to absorption. not knowing your equipment and how much you boil off an hour its hard to be exact. but it you boil for an hour and lose 1.25 gallons and if you left .25 gallons behind in trub loss.. you'd need 5.202 gallons of water. if you squeeze the hell out of the bag you could get by with 5 gallons, if not then go with 5.25 gallons.
 
as far as the strike temp. what is your desired mash temp? are you preheating the cooler? what is your grain temp?

Strike temp 155. The rubbbermaid cooler would be room temp so from what I've been reading my total water would be 166 then stir in grains. Leave it mashing for an hour string every fifteen minutes.

Grain temp would be I guessing 60 to 65 degrees. The grains were only milled once at LHBS.

And thank you for your response I was tying to figure the absorption rate and my math was grains 9.75 x 1.5 quarts and that seem low with boil off and absorption.
 
well... 10 degrees above IF you were doing BIAB in your kettle. you want the water temp in your cooler to be about 10 above your desired strike temp when adding those 60-65 degree grains. since the cooler isn't preheated you're going to lose temp to the thermal mass of the cooler coming up to temp.

if you have a large enough kettle, I would suggest skipping the cooler. just wrap the kettle in a couple old blankets or a sleeping bag and forget it for 60-90 minutes. if you insist on using a cooler, convert it to a mash tun and do a traditional mash.
 
well... 10 degrees above IF you were doing BIAB in your kettle. you want the water temp in your cooler to be about 10 above your desired strike temp when adding those 60-65 degree grains. since the cooler isn't preheated you're going to lose temp to the thermal mass of the cooler coming up to temp.

if you have a large enough kettle, I would suggest skipping the cooler. just wrap the kettle in a couple old blankets or a sleeping bag and forget it for 60-90 minutes. if you insist on using a cooler, convert it to a mash tun and do a traditional mash.

Thats the goal but don't have the parts for the mash tun and it's little cold to leave in kettle
 
Thats the goal but don't have the parts for the mash tun and it's little cold to leave in kettle


lol... cold.. you're in Cali.. Its really not too cold. I've done BIAB in 23F temps. the thermal mass of the water and grains will hold heat and if wrapped in a couple layers of blankets it'll stay warm.. a majority of the conversion will take place in the first 30 minutes.. a temp drop of a couple degrees over a 60-90 minute mash won't make a difference in the final product. this isn't rocket science.. remember people were making beer long before thermometers were invented. I promise that in the end you'll still end up with beer.
 
Just did a BIAB the weekend before last and it was approximately 30F in the garage. I brought the 6 gallons up to temp, wrapped the kettle snugly in its blanket and went inside for 45 minutes. All total it lost 1.5 degrees which isn't too bad.. This is of course with no wind blowing across the pot to cool things down.
 
Ok this what I did .

Mashed in with 165 strike unhear cooler adds grain closed it up.
Checked temp at 15 mins and stirred temp read 150.
Checked temp at 45 mins and stirred still 150.
At 60 min stirred and squeezed.
Pulled hydro and est 140 f corrected reading 1.051.
So now starting to boil and guess my eff ???
 
looks like you're on your way to making beer! I have 25 minutes left in my 90 minute mash..since mine is a stout and wanting a full body my target was 156.... knowing my setup, I started at 158 and after 65 minutes it's holding at 156 if it drops to 154 in the next 25 minutes it's not going to hurt a thing.

your beer since it was mashed at 150 the entire time, will be on the thin side body wise. what style are you making?
 
California common / anchor steam using white labs 810 lagar.

Everybody do helpful here on hbt. Just when I think I know what I'm doing I get a lesson. Haha
 
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