I’ve done tours of Miller and Budweiser, both in Central, NY (when they operated breweries there). I was underage, but that didn’t matter then. Besides, I was with my parents, I was eight, and I wasn’t getting the free bottle of beer at the end of the tour.
Nestle Chocolate, in Fulton, NY. (also gone)
Went on a Pretzel tour somewhere in PA, but can’t recall which company. Again, years ago!
When I was scool-aged, we took school trips with tours to GE where they made small appliances and Carrier Air-Conditioning. We also took trips to several other manufacturing plants which are long gone.