The farm animals. The cats, The picnic area. The red wines. The white wine (Madame Preston). The olive oil. The organic veggies. Most importantly, the bread -- there is no better in my experience, and (this is important to me) it is not going to raise your blood sugar by much -- about the same as our best local whole wheat bread, but it tastes like the high-end Acme-style bread you find in the best restaurants. They won't charge your for tastes if you are buying a bottle, and naturally you can only serve their wines for your picnic, so you will buy a bottle (Zin and their Italian varietal are my favorites. In the spring, you'll drive past a lovely seasonal creek on the way to the tasting room. And, unlike some of their neighbors, Preston combines good wine with a wholly authentic atmosphere.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.