Stinkers: Stinker beans are generally caused as a result of over-fermentation, and due to improper cleaning of fermentation tanks and washing channels. Beans adhering to the pulper vats, if not cleaned meticulously, become stinkers. Stinker beans, when crushed or cut, emanate a very unpleasant odor. They taint the liquor, producing an unpleasant taste in the cup, and give a flavor described as 'over-fermented', 'unclean' or even 'foul'. One or two stinker beans can contaminate and spoil a whole batch of coffee. See also 'Discoloured', under 'Defects – Appearance / Coloration', above. - coffee-ota.org
There are times when coffee is fun and there are times when it is a lot of work. Cupping through slight roast variances from one single coffee roasted several times that when charted out look almost identical is definitely work.
I ran across this one thing that was just disgusting. A stinky bean (or two). Out of a dozen roasts and multiple bags, this showed up in two cups only.
Dry aroma, Skunk. Wet aroma like body odor. Taste was like 'someone brewed the coffee with toenail clippings.' Completely disgusting and foul. Out of six cups, two had this and I suspect it was because they were ground one after another.
I have never really cupped this before and yet this was so distinct in those two cups alone that it led me to realize why it is so essential to cup 3-6 cups of every coffee evaluated on a table.