re: A Chef's Perspective

Wine consumed by sommeliers?

Really not much, if any. The wines are obviously tasted prior to purchase. Then a quick sniff test when opening tableside is adequate to make sure the bottle isn't "off".
Sometimes guests offer mgmt or myself a glass or a taste of a special bottle.
However my staff nor myself don't drink during service. It's a bad precedent and contributes zero to the ability to perform our jobs.