Ever heard someone say, “Oh, that last glass of wine from the bottle is weaker”? That’s a myth. The alcohol is evenly distributed—unless you’ve left it open for a month, it’s not going to magically separate. That’s not how chemistry works. The only thing that changes is your perception after a few glasses. You know what I mean.
So if you’re worried about getting less buzzed from an open bottle, don’t be. The alcohol is loyal. It’s your taste buds that might be fickle.