

The cap and the bottle in soft drinks are made of PET. Most deposit schemes will accept plastic (PET), or aluminium and a machine will separate and sort the material into the appropriate bin. Cans get melted down, plastic is stripped, washed, turned into pellets and fed back into hoppers that make new bottles. Because it’s all the same plastic material it can be ground up into pellets and fed back into a machine to make new bottles. The biggest issue is probably that caps are usually black, red, blue or whatever so I imagine somewhere in the process the chopped up plastic goes past cameras that sort fragments by colour.
Germany collects glass, plastic & aluminium. Glass and plastic can be single use or multiuse. It’s kind of interesting how most beer is sold multi-use (every brand is using the same size bottles) to reduce the amount of recycling necessary. Beer bottles can be washed and reused rather than broken into cullet and remelted. I don’t know what France does but I could see people losing their minds if wine bottles were standardised the way beer is. But really glass could be collected and recycled even if it isn’t reusable.