Agreed. I went to Burgundy this summer with some friends. One of the people spent the entire time in people’s cellars taking notes on his phone. Very little interaction with the producer or his surroundings. I thought he was working until after several stops he said that he was taking notes. My guess is that most of the producers had no idea what my friend was doing and thought he was totally uninterested. So, be careful with what you are doing and engage with the producer.
Lots of good advice given here!
We have found that most of our winemakers enjoy beer (shocking as that may seem) and are most appreciative of craft beers. Since you live in California and have access to some really good small production craft breweries, I might suggest that you bring some IPA’s.