Is there a good web app, or perhaps a ball park conversion formula for lbs. of grain to OG assuming 70% efficiency?
I'd like to be able to look at a grain bill and modify it slightly if I want it to be slightly stronger or weaker, but do it in a mathematical way.
Additionally, I would like to be able to measure my OG and see how it compares to what it should be. A recipe giving you what they got is all well and good, but I would like to be able to check my own version of a recipe against a specific value especially if I tweak the grain bill a little bit.
Thanks in advance.