Originally Posted by Jonnymack123
I have a lot of questions because I not only worry about every little detail pertaining to everything, but I'm also new to homebrewing (i.e. I haven't attempted it yet, but I'm getting ready to). How do you test the gravity of a beer in the primary fermentation vessel without introducing oxygen to the system? Or do you just pop of the air lock/cork, test it, and then allow the yeast to "push" the oxygen back out? Do you guys just test it after the primary fermentation appears complete or do you test it earlier on and more often? Is it okay to dump the tested beer back into the fermentation vessel assuming that the devices used to test the gravity were sanitized? Also, the gravity of the beer should be near its final gravity when you move it to secondary fermentation correct? I hope all of these questions make sense... THANKS!
No need to worry about opening up your fermenter to take readings. I know that the air-tight lid w/ gasket and that crazy little airlock device give the impression that the goal is to keep your wort away from ALL exposure to air from the moment you push down on the lid until everything is "done" happening and it's bottling day. But it's misleading. Exposing the wort to the air to take readings is not only ok, but good practice. Just be careful... you'll be tempted to lean over and take a hearty whiff and maybe your wife/GF will want to as well... make sure you don't drop sweater lint from your head or something in the bucket and make sure your wife doesn't let her hair fall down into it. Don't laugh, it's easily done! My preferred reading method for my fermenter bucket is a simple turkey baster to withdraw a sample and my hydrometer in tube. Basically here's what I do:
Make up some sanitizer in a pot - I use a 2 min soak one. I fill my baster with it and let it sink down so the outside contacts the solution too. I also fill my hydrometer tube(not because I will return the wort, but because I'm about to drink from this tube) While it's sitting, I go to my bucket and carefully loosen the lid all around. I always wipe down the lid top first, JUST in case
. I move the bucket to an open area - ie, I ferment in a closet with a shelf above the bucket... I move it out into the open JUST in case something falls like dust or lint. Then I go get my baster. I carefully take the sample from around the middle depth of the wort, put the lid back on, and bring the sample to the kitchen to put it into my tube. I stick my hydrometer in, spin it a bit to make sure it isn't clinging, and read it. I write down the gravity. I then Take out the hydrometer and stick in my thermometer. I wait for it to settle for a min or so and take the temp and write that down too. Then, providing the sample is being taken after a few days or more of fermentation, I drink the sample wort. I then adjust my gravity reading to the temperature with the formula/calculator and Clean up and I'm done!
Don't rely on the airlock to tell you when your fermentation is done. As others have said, so many variables will affect this and a still airlock is an indication of a still airlock and nothing more! When you THINK the fermentation is done, take a gravity reading and wait a couple days. Take another right before bottling to make sure it hasn't changed, then you know it's bottle time!