Calculate Pre-boil based on boil rate and OG?

[SethOscar]

So I neglected to stir my wort during my first brew on a new HERMS setup, and the result was my OG was higher than pre-boil. Is there a way to calculate the pre-boil gravity based on my boil rate and OG? Just trying to calculate a ballpark efficiency for my first batch... or do I now have to wait until the next run?

Thanks!

Boil rate = 1.5g / hr
OG = 1.056 corrected

 

[Hammy71]

You would be well served to purchase some software like BeerSmith2. This calculator will do all the things you are asking. I'm sure there is a formula for what you are seeking....but I'm way too lazy for that stuff....LOL

http://beersmith.com/

There's a free trial period to boot

 

[ba-brewer]

pre-boil gravity = (post boil volume)/(pre-boil volume)*(post boil gravity)

assuming 7gal start and 5.5gal finish
take the value right of the decimal point time 1000
pre-boil gravity = 5.5/7*56
pre-boil gravity = 44

divide by 1000 and add 1 to 1.044

 

[SethOscar]

You would be well served to purchase some software like BeerSmith2. This calculator will do all the things you are asking. I'm sure there is a formula for what you are seeking....but I'm way too lazy for that stuff....LOL

http://beersmith.com/

There's a free trial period to boot

I have BeerAlchemy2 and BeerTools Pro - I just neglected to take an accurate measurement, and couldn't find a suitable calculator in either program to make this calculation.

pre-boil gravity = (post boil volume)/(pre-boil volume)*(post boil gravity)

assuming 7gal start and 5.5gal finish
take the value right of the decimal point time 1000
pre-boil gravity = 5.5/7*56
pre-boil gravity = 44

divide by 1000 and add 1 to 1.044

Thank you for this - exactly what I was missing