Just did my second all-grain batch on Friday. It went well, although I'm still learning my system. But due to getting started later than expected, it got pretty cold as we were wrapping up. It wasn't until the next morning that I realized I forgot to take an original gravity reading in our rush to get inside. I know that BeerAlchemy has a calculator that takes a hydrometer sample and a refractometer reading at the end and can tell you the estimated original gravity. I was wondering I anyone has had experience with this or has an idea of how accurate it is. Not that's it's a huge deal that I know what it started out at, but I just like to put it in my notes. But hey, either way I'll have beer. Thanks in advance.