Need a quick answer/peace of mind

I am going to brew in the morning doing BIAB. I have watched endless videos, read almost the entire sticky on BIAB and I just need some quick guidance before I continue. Here is my plan (inspired by brewing TV: Jake's got a brand new bag):

3 gal batch
7.5 gal aluminum turkey fryer
12.75 lbs grain
60 min at 152
10 min at 168
pull bag out and let it drain for awhile (no rinsing, sparging, etc)
continue with 60 min reg boil

HOW MUCH WATER WOULD I NEED????

I have the recipe on Beersmith, but it acts as if it is an all grain deal and they say 6.21 gal. I was thinking 3 gal final volume + 1.53 gal grain absorption + .50 gal boil off + .22 gal misc (grub, cooling, etc) for an estimate of 5.25 gal. That is a whole gallon difference.

Just a little advice for this newb here would be great.

Thanks in advance..

Well you will need something around 4 gallons of wort to boil for one hour down to 3 gallons. You could calculate how much water to use in the beginning and how much the grain will absorb..but I say it would be easier to just use a simple qts/lb ratio. (Typically 1.25-2 qts H2O / lb of grain). After you pull out the grains and drain them, either top off to 4 gallons, or put a strainer over the brew kettle, your grain bag on the strainer, and pour your top off water through the grains to give them a little rinse til you get to 4 gallons.

Edit: The nice thing about doing it this way is that is easy to use c1v1=c2v2 to help you judge how much volume you need to hit your target gravity, if you are concerned about it. If you add all of your water first and you find out that you used too much, then you pretty much are going to have to boil for a longer time, or you will end up with a weaker beer.

try this calculator by hbt member Mrgstiffler: https://www.homebrewtalk.com/f36/simple-biab-calculator-265138/

6,21 gallons sounds about right for my equipment. Did you enter your equipment into BrewSmith?
Also, there is 4 different BIAB settings in the mash drop down menu. Which one did you use?

acidrain said:

6,21 gallons sounds about right for my equipment. Did you enter your equipment into BrewSmith?
Also, there is 4 different BIAB settings in the mash drop down menu. Which one did you use?

Click to expand...

You need 6.21 gallons of wort for 3 gallons of final volume? What do you need for a 5 gallon batch?

6.2 gallons sounds too high. I think your original calculation is right. That is, if your boil off rate is what you actually have.

Thank you for all the advice. After a night of sleep I realized a couple errors in my entry into beer smith. After taking the tips from you fellow home brewers my new calculated volume of water is 4.81 gallons. I feel much better about this and now I can RDWHAHB

CHEERS!