Grain bill and water calculations

[Barbell]

Guys, I am a little bit stuck on some math here

I need to end up with 50L of wort before boiling with 1.06 gravity. My efficiency is 75%.

How do I calculate how much grains and water do I need?


Thanks

 

[max384]

You calculate your grain bill first either using a recipe or designing your own with appropriate software. Then you calculate your water. I use this online calculator:

http://www.brew365.com/mash_sparge_water_calculator.php

 

[indymedic]

Do you have a recipe?

 

[McKnuckle]

You need to use a calculator.

I used my calculator, and plugged in 100% American 2-row as a grain bill (37 ppg). At 75% mash efficiency, I end up with:

14.8 gallons of total water
26.5 lbs grain
13.21 gallons ready to boil (50L)
I'm using 0.06 gal/lbs grain absorption rate

Your recipe will change this, but it's in the ballpark.

 

[Barbell]

Don't have the recipe. This is my 12th batch and I want to make something on my own (and know the math behind it).

I wiggled my way around by using brewers friend calcucators.

 

[Barbell]

You need to use a calculator.

I used my calculator, and plugged in 100% American 2-row as a grain bill (37 ppg). At 75% mash efficiency, I end up with:

14.8 gallons of total water
26.5 lbs grain
13.21 gallons ready to boil (50L)
I'm using 0.06 gal/lbs grain absorption rate

Your recipe will change this, but it's in the ballpark.

Awesome, exactly what I got!

 

[dstockwell]

Guys, I am a little bit stuck on some math here

I need to end up with 50L of wort before boiling with 1.06 gravity. My efficiency is 75%.

How do I calculate how much grains and water do I need?


Thanks

So without knowing a little more info we can try and figure. Guessing the batch size is 37L

Absorption Loss:
(lbs of Grain) x 0.20) = Absorption loss in gallons converted = 22.7L

So somewhere in the neighborhood of 72L with 30lbs of grain.

Just a guess..

 

[chickypad]

Absorption Loss:
(lbs of Grain) x 0.20) = Absorption loss in gallons converted = 22.7L

Where are you getting the absorption loss of .2 gal per lb? For a regular tun it's more like .12 per lb and with BIAB most get .06-.09 depending on how hard they squeeze. OP, are you BIAB'ing?

 

[Barbell]

No BIABing here boss

 

[dstockwell]

Where are you getting the absorption loss of .2 gal per lb?

I just searched the forum here to try and answer the question, so I wasn't sure.

https://www.homebrewtalk.com/showthread.php?t=52012

 

[chickypad]

No BIABing here boss

If that's the case you had better change the .06 gal per lb water absorption estimate. The much more common number for a regular tun is about 1/2 qt per lb = 1/8 gal or .12-.125 gal per lb. I've brewed on multiple different systems both batch and fly sparging and that's what I get, it's also the default in Beersmith and Brewer's friend. Apparently a few guys in that other thread linked use 0.2 but that sounds uncommon to me. I'd start with .125 and then measure your own system on the first run. If you fly sparge you can always heat up extra water if you have enough space so you don't run short.