Originally Posted by funkydrummer88
If I get a hyrdometer, I should test it for 2 consecutive days to see when it's the same reading, correct? This means that I must open my batch of beer. Then I must dip the hydrometer into the beer, or use the measuring flask correct? I will sanitize, but wouldn't this hurt the beer itself as far as oxidation, and bacteria?
The effect of opening your fermentor is pretty minimal if you sanitize all your equipment really well. Just make sure you don't shake the carboy/bucket up at all when you're taking a reading and you won't really have to worry about oxidation.
I usually take gravity reading for three consecutive days after 3-4 weeks has past. Leaving you're beer in the fermentor for that long won't affect the taste. If you get the same reading on those consecutive days you're probably good to bottle.