At the Inertia Direct Symposium, there were lots of questions about winery blogging, and the panelists (Tom Wark, Julie Ann Kodmur, Deb Harkness and myself) all recommended being authentic. Here's an excellent post from Darren Rowse about how to make your blog more personal:
I’m not talking about starting a personal blog where you share lots of personal information - what I’m focusing on here is building a blog that connects with people in a more personal way around your niche topic.
Rowse suggests a number of approaches (most with link to a blog post he's done on that specific approach). If you're a winery blogger, or thinking about getting started, go read his post and follow the links. His Problogger site is oriented to people who want to make money from blogging, but it's still aimed at creating effective blogs (which is how you make money with blogs).
(Here's my original post on the Winery Blogging panel at the Inertia Direct Symposium.)