The grav reading will tell you NOW where on the journey from Original gravity to terminal gravity, your beer really is. You have the OG, if you didn't take one initially, your recipe still should tell you what the grav is for that recipe, in extract it is foolproof, if it's ag, you should have an approximation on your recipe, which will be close enough for government work...Or you can enter the recipe into any beer calculator even the free ones found online.
Your recipe should also tell you what the FG should be..And your current gravity reading will tell you what you beer is doing NOW. If it's barely been fermenting, or if it's close to being done, or if it IS done...
