Originally Posted by mikesalvo
how will the hydrometer readings tell me when fermentation is done.
Depending on the starting readings (or a guess, if you didn't take any) and the final readings, you can know when it's done. For example, if you take a reading now and it's 1.020, it's not done. But if the reading is .990, it's done. Without a hydrometer, you can sort of guess when it's done. When it's been clear for a month, and not dropping any more sediment, you can say it's probably done.
If it's not clear, and it's still dropping sediment, it's definitely not done.