Apparently many people cite a visit to a coffee farm as a highlight of their time in Colombia. I visited two between Manizales and Pereira, and here offer my comparison.
Hacienda Venecia
How to get there: Coming from the north on a Manizales-bound bus, ask the driver to let you off at San Peregrino bridge. (Maybe keep your eye on a map incase they forget.) Go into Las Palmas restaurant and ask them to call the Hacienda for you. Have a drink while they send a jeep up to get you. The same system works in reverse when you leave as it´s slightly too far to walk with luggage.
Pros: Stunning scenery, very organised place, three different accommodation options including a proper hostel with private rooms, spacious dorms and camping (22k), hammocks, hot water, a kitchen, breakfast included and a small shop for beer and other basics!
Very detailed, informative morning tour. Good, optional lunch after the tour. Birding guide and binoculars available from reception. Everybody very friendly.
Cons: None really.
Hacienda Guayabal
How to get there: Coming from the north on a Pereira-bound bus, ask the driver to let you off at Guayabal. (Maybe keep your eye on a map incase they forget.) From the main road it´s a short, uphill walk to the Hacienda (follow signs).
Pros: Stunning scenery, also very organised though a smaller operation, private rooms only, hot water, breakfast included, lunch/dinner 25k. Equally informative - though slighly different - tour (morning or afternoon). You get a certificate! Everybody very friendly.
Cons: No dorms or camping, so it works out a quite a bit more expensive than Venecia especially for solo travellers.