The following is a very brief list of the coffee plantations offering tours:
Greenwell Farms in Kealakekua - If you are looking for a great tour and coffee tasting, you can't do better than Greenwell, a must see while on the Kona coast!
Kona Joe Coffee LLC - 79-7346 Mamalahoa Hwy in Kealakekua Their award-winning coffee is certified by the Hawaii State Department of Agriculture, and all orders are shipped directly from the farm.
Mountain Thunder Coffee Plantation - 75-1027 Henry Street #354 in Kailua-Kona Provides outstanding coffee tours to the public.