Need info on wine tasting appointments

All the wine tasting I've done has always been at wineries that were open to the general public. What are the protocals for making appointments at those that are not? Are you obligated to purchase, or is it poor form not to? I tasted a Ramey Chard recently and liked it. I'm curious about thier other wines and would like to try some. I'm going to be in the area next weekend and was thinking about giving them a call.

What are the protocals for making appointments at those that are not? Are you obligated to purchase, or is it poor form not to?

Depends on the producer. I have no idea about Ramey, but in general some wineries are not open for appointments because they don't make much wine. So they may have a bit for you to taste just for general PR purposes but they will already have sold their entire production and would be doing you a favor by selling.

Other wineries are not open for appointments because they don't have the staff and in many cases they have excess production so it would be polite to buy something after they took special time out to serve you.