You're guaranteed a sugar-high on the 45-minute tour through Jelly Belly's main factory in Fairfield, CA. Guides lead visitors over glass-enclosed catwalks that provide a bird's-eye view of how workers process, flavor, color, sort and package these jewel-like candies (not surprisingly, sugar is a key ingredient every step of the way). The tour also includes a detailed explanation of how Jelly Belly comes up with such authentic flavors (hint: some of the flavors are real). The factory is dormant on weekends, so be sure to go during the week. All tours include a free 2-oz. bag of jelly beans and conclude in the factory store (where it is nearly impossible not to buy more beans for the road).
Hershey's Chocolate World
Part theme park, part insider tour, Hershey's Chocolate World in Hershey, PA, is one of the best ways to see how Hershey's Kisses (and just about every other Hershey's brand) come to life. While there is no actual walkabout on the factory floor, visitors are invited to take a virtual tour that explains how Hershey's chocolate is made -- from bean to bar. The tour is so realistic that at one point, the smell of fresh chocolate wafts through the room. A new attraction for 2010 enables guests to create their own chocolate treats by topping (very real) traditional Hershey's bars with whatever they fancy. There's also a 3-D movie, and the opportunity to help package fresh-off-the-line Kisses.
Louisville Slugger Museum and Factory
From the moment you glimpse the Louisville Slugger Museum and Factory in Louisville, KY, you know what's made there: A giant sculpture of a bat rests against the building facade. The 25-minute tour leads visitors through the bat production line, giving them an inside-baseball perspective on how maple bats are carved from log-like hunks of wood. Guests can also explore the on-site museum, which tells the story of wooden bats from the late 1800s until today. All visitors (yes, even you, Mom and Dad) receive a miniature souvenir bat at the end of the tour. There is no bat production on Sundays, holidays or Saturdays between December and April, so be sure to avoid visiting then.
Ben & Jerry's Ice Cream
You'd be hard-pressed to find a sweet-tooth who doesn't like Ben & Jerry's ice cream; that's why the factory tour at the company's Waterbury, VT, headquarters is so much fun. The tour gives visitors an elevated view of the factory floor. All the while, guides explain how ice cream goes from milk and sugar into frozen goodness in a pint. Thirty-minute tours begin with a video that documents how Ben Cohen and Jerry Greenfield became friends in the 7th grade; they end with a taste-test of fresh-off-the-line samples. Another fun aspect of the experience is the "Flavor Graveyard" behind the plant -- a place where tombstones mark the untimely end to some of the company's ill-fated flavors.
American Whistle Corporation
Metal whistles are as American as baseball and apple pie, which means a factory tour at the American Whistle Corporation in Columbus, OH, is a noble exercise in patriotism. AWC is the only manufacturer of metal whistles in the US, and the 45-minute tour takes visitors behind the scenes to see precisely how these musical instruments are made (and how that tiny ball gets inside). Along the way, guides point out one-of-a-kind machinery crafted specifically for AWC, and they share interesting tidbits about whistles throughout time (the instruments date back hundreds of years). At the conclusion of the tour, guests whet their whistles with shiny new instruments they can keep.