How to hit OG

[kabl3]

I recently bought a 100q cooler, to brew 10 gal beers.
I guess that I also just started checking gravity.
My question is, do you buy enough grains for 12 gal, to account for boil off,or just10 gal, boil then add water to bring it back up?

 

[Yooper]

I recently bought a 100q cooler, to brew 10 gal beers.
I guess that I also just started checking gravity.
My question is, do you buy enough grains for 12 gal, to account for boil off,or just10 gal, boil then add water to bring it back up?

You'll want to make your recipe so that you can make a 10 gallon batch. So, if you find a 5 gallon recipe you like, just double that to get your recipe.

 

[kabl3]

That's what I do, but my OG is always off

 

[billl]

Recipes are built around a particular efficiency - typically 75%. If your efficiency is not 75%, you won't hit your OG unless you scale up/down the recipe based on your actual system.