There are two advantages to exploring smaller wineries.
Firstly, large wineries cater to the masses. Their advantage comes in that they offer a consistent taste, rather like going to a chain restaurant in a foreign country. You know what you can get, and they are widely available.
Smaller wineries can cater to smaller taste groups, so they can experiment in ways that might not be appealing to a wide enough audience to justify production by a large-scale winery.
So, if you want to experiment with different tastes, a smaller winery might offer varieties you wouldn't see from a mainstream, larger winery.
The second reason, and the most important one in my opinion, is that wine comes with a story, and smaller wineries tend to have better stories.
I freely admit in my bias to this, but let me offer you a pair of examples. About an hour's drive away from me are some spectacular and world renowned wineries. They are huge wineries that occupy hundreds of acres of land and are major tourist attractions. Then, about 20 minutes north of me is a small winery on about 20 acres. It's a lucky day when I find a bottle of their wine in any store other than the one they run, and they hold yoga classes in the fields of grapes during the summer.
While I would happily drink a glass of wine from any of those three, can you guess which one I think has the better story?
The best part about wine is that the story and the taste are so intertwined. If you find a winery with a story you love, and a taste that you can appreciate, the wine become so much more than just a drink, it becomes a full experience.
Just be careful that you get the story and not they hype. If you want to know more about this, check out my article Buy the Wine, Not the Hype. Or, if you're already a fan of wine, learn more about the health benefits of white wine.