Ok, so it is not really potatoes in my coffee, it is however, Potato Taste Defect.
Potato Defect—also known as Potato Taste Defect, or PTD—occurs in coffees from Rwanda, Western Uganda, Burundi, and the Democratic Republic of Congo. It smells and tastes exactly like what the name implies: raw potatoes.
There are very low, if any, visual identifiers that correlate to PTD defective seeds (or coffee beans). In fact, most defective seeds look perfectly normal to the human eye and show no visible insect damage or UV fluorescence. Therefore, unlike other defects, there is no “preventative maintenance” in processing or sorting methodologies that the producer can do to ensure a highly reduced rate of PTD. There is, however, a smell associated with this defect, and it is very identifiable in freshly-ground roasted coffee. We have done research to better understand the defect occurrence rate in the coffees we buy and are sharing our recommended protocols to avoid tasting the defect when brewing.
In our research tracking PTD, the average occurrence rate of this defect is 1 in approximately 1550 grams in the coffees we buy. This means in every 3.3 pounds or so, the likelihood of hitting one PTD seed (coffee bean) is fairly high. It also means that the chances of experiencing potato defect in a 12 oz bag are low. Of course, there is a large element of randomness involved in this—that is just the nature of the beast. There is no known toxicity in the defect itself, and it is safe to consume, should you encounter it once brewed. However, since one defective bean can affect the taste of the resulting brew, we are sharing our recommended steps to take to avoid tasting potato.
Thank you to Counter Culture Coffee for sharing their research.