Potato Flaw? – Potato Defect is a unique and rare type of defect found solely in Burundi and Rwandan coffees. It’s caused by an unexplained bacteria that gets into the coffee cherry pods and creates a toxin that gives the coffee a lousy flavor.
According to some studies, the Potato Defect originates when airborne germs enter a puncture or rip in the coffee berry’s outer layer. Failures like this might happen for a variety of reasons. Intestine ( Antestiopsis orbitalis ), a little blood-sucking bug that produces holes outside the coffee berry that germs can enter, is the most common cause.
Potato flaws aren’t dangerous to your health, but they give out a distinct aroma when you roast and grind the coffee, similar to the smell of a raw potato. Because the Potato Defect can only be recognized after the coffee has been burned, a coffee roaster will not notice this type of defect in a batch of coffee until it has been brewed.
The difficulty is that the Potato flaw does not emerge in quantity but rather on a few individual beans, making it impossible to identify and remove the defective beans, even though it impacts the flavor of the entire batch of coffee.