Simple BIAB Calculator

[KIAKillerXJ]

I've used this calc like 5 times now, and the strike temps always come out perfect, and have hit my OGs as well.

The first 4 times though I've ended up with to much volume, about 1 gallon too much each time. Yesterday I subtracted 1 gallon from the measurement, and came out perfectly for a 5.5 ending volume into the fermenter.

 

[mrgstiffler]

I've used this calc like 5 times now, and the strike temps always come out perfect, and have hit my OGs as well.

The first 4 times though I've ended up with to much volume, about 1 gallon too much each time. Yesterday I subtracted 1 gallon from the measurement, and came out perfectly for a 5.5 ending volume into the fermenter.

Yeah, I've had that same problem too. I think you get less absorption with BIAB. Probably because when you lift the bag, the grains get compacted. You'll lose even less if you squeeze the bag.

 

[Veedo]

This looks awesome. Going to do my first biab soon and will be trying this out. Thanks for putting the time into this. Should i subtract a gallon for absorbtion, or kust run with what it spits out?

 

[mrgstiffler]

This looks awesome. Going to do my first biab soon and will be trying this out. Thanks for putting the time into this. Should i subtract a gallon for absorbtion, or kust run with what it spits out?

For my pot that has a 15.825" diameter, I've found that subtracting 1/2" from the calculated strike water is pretty much right on. But I don't squeeze the crap out of my bag like some people. I squeeze it until I hit my target.

 

[mrgstiffler]

UPDATE: I've updated the calculator by adding some styling and tips. It should be very accurate now. BIAB definitely leads to higher collection than traditional techniques. I believe this is because there is more pressure on the grains when you lift the bag. Also, it seems that people tend to squeeze the crap out of their bags. I'm going to add the mashout option next.

 

[mrgstiffler]

OK, mashout option has been added. I don't do mashouts so I haven't actually tested it, but it's about what other calculators come up with.

 

[Rifester]

Nice work Greg! :rockin:

 

[mrgstiffler]

Thanks!

 

[Beer-lord]

I've used it twice and it's pretty much dead on for me.
Thanks for posting the calc.

 

[mrgstiffler]

I've used it twice and it's pretty much dead on for me.
Thanks for posting the calc.

Sweet! Glad you found it useful!

 

[MarkD]

This is great, and the problems I've had have been due to my noob mistakes, not the calculator. (I had the diameter of my pot slightly wrong the first time, next I was wrong on my boil-off rate and I spilled some wort once.) I use a stainless steel ruler to measure volumes and last time I was within a quart of hitting my target volume into the fermenter. It was snowing out, and I probably missed the boil off rate due to a cold propane tank.

This has everything I need, and nothing I don't. I would consider going back to extract kits without it. Thanks again.

 

[mrgstiffler]

This is great, and the problems I've had have been due to my noob mistakes, not the calculator. (I had the diameter of my pot slightly wrong the first time, next I was wrong on my boil-off rate and I spilled some wort once.) I use a stainless steel ruler to measure volumes and last time I was within a quart of hitting my target volume into the fermenter. It was snowing out, and I probably missed the boil off rate due to a cold propane tank.

This has everything I need, and nothing I don't. I would consider going back to extract kits without it. Thanks again.

Were you a quart high or a quart low?

 

[Bigscience]

Nice! Do you mind sharing the constants you're using for grain and hop absorption? Also, another nice tweak may be to have one for pellet and one for whole hops as I believe they are different (although I only use whole). Solid work work though.

 

[mrgstiffler]

Nice! Do you mind sharing the constants you're using for grain and hop absorption? Also, another nice tweak may be to have one for pellet and one for whole hops as I believe they are different (although I only use whole). Solid work work though.

Sorry it took so long. I read your post and then forgot to reply.

Grain absorption: .125 gallon/lb
Hop absorption: .0365 gallon/lb

The grain absorption is tricky for BIAB. Lifting up the bag puts more pressure on the grains so less wort is retained. People also squeeze to different levels. .125 gallon/lb should be about right if you lift the bag and hold it there until the drainage slows to a drizzle.

 

[mrgstiffler]

UPDATE: Metric units are now supported. Should help all of our international BIAB friends.

 

[daksin]

UPDATE: Your avatar is still from a really terrible webcomic drawn by a really talented artist! What are you doing to improve this feature?

 

[mrgstiffler]

UPDATE: Your avatar is still from a really terrible webcomic drawn by a really talented artist! What are you doing to improve this feature?

lol, Least I Could Do has surprised Calvin and Hobbes as my favorite comic of all time. Lar deSouza is a fantastic artist. Ryan Sohmer may come off as a bit of a sexist but I think that's more just pandering to his audience. I identify with Rayne because he does what he wants but always stands up for his friends and what's ultimately right. Plus, it's funny as hell.

 

[ArcLight]

Nice calculator - thank you.

A suggested enhancement -
display how much volume the grain displaces.
So 16 lbs may displace 4 quarts, meaning instead of X inches, you will end up with Y inches.

This rather nice calculator shows it. (I didn't write it)
http://www.buildabeer.org/beerquickcalc.php


I will have to experiment more with the wort retention by the grain. Is it as high as 0.125?
I thought it was more like 0.1.
Its not easy to squeeze big bags, but smaller bags can be SCOOBED
For them I wonder if the wort retention is more like 0.075
(Squeeze the Crap Out Of the Bag)

 

[mrgstiffler]

I can absolutely do that. Would definitely be useful.

Grain absorption for BIAB is difficult because everyone has their own methods. Some people squeeze that crap out of their bags, others hang them and just let them drain. The calculator uses .125 and to hit the preboil volume I usually have to squeeze a decent amount.

 

[normnmiles]

Is there still an offline option? Will the link you posted in reply #5 download the most current version? Thanks for making such a useful tool.

 

[mrgstiffler]

Is there still an offline option? Will the link you posted in reply #5 download the most current version? Thanks for making such a useful tool.

That will still work yes, but it doesn't include the addition of metric units. I'll zip up the new version when I get the chance. The link will be the same.

 

[SkipWankman]

Quick question, what is the grain temperature? Are we talking just like ambient temperature? Or if somebody stores the grains in the refrigerator or something? Sorry if this is a dumb question.

 

[mrgstiffler]

Quick question, what is the grain temperature? Are we talking just like ambient temperature? Or if somebody stores the grains in the refrigerator or something? Sorry if this is a dumb question.

Yes, it is the temperature of the grains, which is usually ambient. This is important for calculating strike temp.

 

[SkipWankman]

Yes, it is the temperature of the grains, which is usually ambient. This is important for calculating strike temp.

Thank you. That is what I figured, I just wanted to be sure. Thanks!

 

[mrgstiffler]

Thank you. That is what I figured, I just wanted to be sure. Thanks!

No problem. Let me know how it goes for you.

 

[SkipWankman]

Will do. Not sure when I am going to brew but it will be soon. I have to see how those measurements (in inches) are going to work. In my pot I have an indented ring near the bottom where a grate sits on, I think it is for steaming tamales, so the measurements are going to be a little off. At least I have the gallon measurements.

 

[kzimmer0817]

I tried this calculator. It is certainly easier to use. The numbers came out a little different than those from using the calculator from the Biabrewer website that someone else had mentioned.

I tried to go to the link with the downloadable zip file and I get that "404 Not Found" error. Has this been moved?

Thanks,
Keith

 

[mrgstiffler]

Yeah, the numbers will be slightly different but pretty close. Make sure you read the bullet points about strike water temp and volume.

I'll check into the zip not being available.

 

[kzimmer0817]

I just clicked on it again this morning and got the "404 Not Found" error. It's this link in posting #5 of this thread.

http://www.gregstiffler.com/biabcalc/biabcalc.zip

I even added "simple" to 2 logical places in the link and still got the error. It's odd that no one else is reporting a problem.

Thanks,
Keith

 

[mrgstiffler]

I just clicked on it again this morning and got the "404 Not Found" error. It's this link in posting #5 of this thread.

http://www.gregstiffler.com/biabcalc/biabcalc.zip

I even added "simple" to 2 logical places in the link and still got the error. It's odd that no one else is reporting a problem.

Thanks,
Keith

Here you go. Looks like it didn't make the transfer when I moved to the new domain.

http://simplebiabcalculator.com/biabcalc.zip