Fairfield, CA
The Jelly Belly Candy Factory in Fairfield, California offers a 40‑minute guided walk through its production line, located about an hour north of San Francisco. Visitors observe the manufacturing of more than 150 confectionery items, including taffy, chocolate, and gummy candies, and learn the detailed process that takes over a week to produce a single Jelly Belly bean. Tour dates and operating hours should be confirmed in advance.
http://jellybelly.com/Cultures/en-US/Fun/Tours/Fairfield+Visitor+Center.htm