Thanks for the question Vinz and for the opportunity to research this. After testing on a number of bottles of wine with differnt levels of wine drunk I can tell you that the balance remains. In fact when the bottle is part empty the wine sloshing back and forth in the bottle makes the holder rock to and froe. You may need to position the neck differently in the hole in the holder depending on how much is drunk. I am looking forward to researching this further and will report back when I recover!
