BIAB Water Volume Calculator

[jbrookeiv]

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.

 

[jbrookeiv]

Also, just tested it on my iPhone, and it works like a charm. SCORE!

 

[jbrookeiv]

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.

 

[ksparkes]

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?

 

[theschick]

Thanks!

 

[jbrookeiv]

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.

 

[kable]

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+?

 

[fishnfever]

Thanks jbrookeiv!! I have been thinking of doing some small all grain batches and this is just what I was looking for :rockin:

 

[Atvar]

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.

 

[cadarnell]

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?

 

[Mysticmead]

no problem at all squeezing the bag for every precious drop of wort

 

[ayoungrad]

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.

 

[jbrookeiv]

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.

 

[johnodon]

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

 

[johnodon]

Here is what I came up with:

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:

I am open to all/any feedback!

John

View attachment BIAB Water Volume Calculator - Copy.PDF

 

[TripHops]

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

 

[Mysticmead]

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

that should be based on squeezing.. if you squeeze REAL hard you can lower that to .050

 

[johnodon]

What Mystic said.

 

[NWMOBrewer]

thread resurrection. I have heard no problems with squeezing. I plan on squeezing tomorrow when I do my first all grain batch using BIAB

 

[UnaBonger]

Would this calculator work with no sparge brewing? I think the concept is similar to BIAB...

 

[Mysticmead]

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.

 

[Satisfaction]

Excellent thread thanks for sharing all.

Putting this information into my brew day arsenal..

 

[zacster]

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?

 

[Mysticmead]

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.

 

[stux]

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

 

[zacster]

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.

 

[artyusmc]

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

 

[Mysticmead]

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.

 

[Mysticmead]

as far as the strike temp. what is your desired mash temp? are you preheating the cooler? what is your grain temp?

 

[artyusmc]

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.