Make your own way to Yountville to meet your guide, then get outfitted with your bike and helmet. After a safety briefing and orientation, set off with your guide to the first of the two wineries of the day.
At each winery, your guide introduces you to your tasting room host, who leads a guided tasting of the flight of wines. Learn about the wine-making philosophies and practices of each winery during your tasting, which generally lasts about an hour.
Expect to bike for about 3 to 5 miles (5 to 8km) to the first winery, a similar distance to the second winery, and another few miles to return at the end of your ride. Longer sections of the route include stops to soak in the scenery, take photos, and hear interesting facts about vineyards and local history from your guide.
At the end of five hours, return to your starting point in Yountville to conclude your tour in the early afternoon.