As a winemaker in a former life…
The black rubber will work ok, unless it’s long term storage (I
assume you’re making bottle stoppers), as will neoprene type O-ring
Metals to avoid (in order from AVOID to avoid) are iron, brass,
bronze, copper, silver, pewter. This is for non-immersed contact, for
immersed contact go with glass and plastics or noble metals (silver
is ok for short periods, as it reacts with the sulphites used in wine
Hope this helps you some.
Cheers, Thomas Janstrom.