ABV-OG calculation without OG

[Jacob]

Don't know how about you but sometimes I forget to check OG after brewing. Also that method may be handy in checking OG of the beer brewed by a friend or even beer from a shop

To check it you'll need 3 things:
1. Refractometer
2. Hydrometer
3. ProMash

Check SG using refractometer & hydrometer and use those numbers in ProMash - Refractometer - % Alcohol, OG and Residual Extract option.