How do i know when my my wine is degased?
That's a great question, which is a little different than how to degas. There's a couple 'tests' that are usually discussed:
1. Poof test. Fill your hydrometer tube half full and plug it with your palm. Shake it and when you release your palm if you hear a forceful poof, you've got gas. This doesn't really work for me as I can get a poof just using warm water.
2. Prickly tongue. Take a sip and see if you can feel that diet soda fizzing on your tongue feel. If so, you've got gas. My tongue is too burnt out from daily diet cokes for this to be sensitive enough for me.
3. Stir test. Put a serving of wine in a wine glass. Take a sip. Is there any 'bite' to it? Now stir it with a fork for a minute. Take another sip. Does it taste the same or better than your first sip? If it's the same then you're probably degassed already. If the stirred sip tastes better it's probably because you drove the CO2 out with the stirring and you need to degas more. This is the most effective test for me.
There may be other tests but those are the most common that I've tried and heard about. Best of luck. Degassing is a PITA and a source of several holy war threads here over the years. For me, one major key is having your wine at 75 degrees before and during degassing. That's the biggest factor that I've found. If you get to a point where you can age, especially in a barrel, then it will likely finish degassing on it's own. If not, then for me the only effective degassing technique I've found is stirring with a wine whip followed by a Harbor Freight vacuum degassing which is discussed in a couple threads.
Good luck.