On our way from New Hampshire to Vermont, we were close to Waterbury, where Ben and Jerry started their icecream adventure. At the factory (now owned by Unilever), we attended a short but nice tour (only 4 dollars/person) and we got a small sample a recently produced icecream. Jammie. Everything is well organized and afterwards you can buy as many icecream and souvenirs as you want ;-). You don't need more time than about 1 hour, because there is not more than described here. Nice stop though.