Formula to calulate original gravity

[Mateo]

I found a formula that allow you to plug in your lbs of grain, volume of water and it would tell you the final gravity.

Here is my dilemma. I have an 8 gallon kettle and would like to do 10 gallon batches.

Here is my idea. I will pre-boil some water 48 hours in advance and chill this water in the keezer/fermentation chamber. The water will be divided into the fermentation tanks. On brew day I have the capacity to mash more than I can boil at the target preboil gravity, however, I can handle so doing a slightly higher gravity with the addition of more grain might just get my to where I want to be for my OG at 10 gallons.

I had all of these formulas in an excel and ready to be put into a VB program but I deleted them when I was making my hydrometer correction program.

Can anyone help me find these.

I am going to get a system capable of boiling more than 8 gallons, but I have an move coming up next year and don't want to have anything extra to move.

 

[Blackgaurd_Brewing]

Get a keggle, they arent much to move empty!

If you cant afford to purchase one of the brew software systems then brewmasters warehouse "brewbuilder" can figure og's based on grain bill, system effienncy and final volume. However, your going to effectively be brewing a big beer and diluting it, so your efficiency is going to be low, and your hop utilization will also be a bit lower.

 

[Mateo]

I write software, so I have no need to buy. Additionally I have yet to see one that does what I want. Too much of things I won't use and too cumbersome. So I am writing my own little program.

I will get a keggle, but I already have an 8 gallon system and do not want to spend any money before the move.

I expect the efficiency to be low but I am hitting 80% consistently and am having to reduce my grain bill to accommodate. That's what got me thinking. I shoot for the high 1.050 range (1.056) and I get 1.070. So I was thinking if its 1.070 a couple more pounds of grain might get me to where I can double my batch size.

I end up with 6 gallons of wort and 5 go into the fermentor. I only need 4 more gallons.

 

[Mateo]

I figured it out:

I1=lbs of grain * points (37 points for Belgian Pilsner Malt)

=I1*0.00075/5+1

or I1*(BrewHouseEff*0.00001)/BatchSize+1

Not sure about the points for Pilsner Malt just read that somewhere.

m.