All my bottles come from recycling. Either from our own store bought source or from the recycling station. Aside from a label, how can I identify a bottle suitable for a batch of sparkling wine?
I have a few that are, by weight, heavy relative to typical bottles. Is there a difference with the tops? I assume there needs to be a neck suitable for the cage.
As Redboat says, a key distinguishing feature is the very top of the neck has a lip that is meant for a cap (like a beer bottle). Just below this is a thick ridge or bulge, that the cage can gain purchase against.