This might blow your mind.
Most roasters don't go into detail on fermentation because people either think it sounds gross or consider it too arcane.
Natural and honey process coffees rely a lot on fermentation. The Pilot Ethiopian coffee you posted a little while back went through the natural process. After that coffee was picked it was dried for several weeks on raised mats, during which ambient microbes went ham on the flesh of the fruit. Once those microbes had largely broken down the flesh and its water had evaporated, the farmer milled off the remaining dried husk to reveal the coffee beans, which were then bagged, shipped, roasted, and sold to you. Because Pilot roasted the coffee lightly, the compounds the microbes left behind heavily impacted its flavor.
Even washed processed coffee is fermented. It's an economical method of removing mucilage, the goo left behind after mechanically stripping most of the fruit off the bean. Mucilage is sugary and microbes love sugar, after a day or so of fermentation the mucilage can be washed off.
Even the coffee included in this kit that was mechanically demucilaged, to minimize fermentation as much as possible, fermented a little bit. Microbes did their level best in the time it took for the coffee to get from the tree to when the machine stripped off the flesh, which would have taken at minimum several hours for the first beans picked in a given load. More realistically it took sixteen to twenty four hours, the lot was probably picked and then demucilaged the next morning.
Microbes are relentless.