If you’ve tasted or purchased a Rwandan, Burundian or Congolese coffee, you’ve probably heard of potato defect. Potato defect is when roasted, ground and brewed coffee smells and tastes like raw potato. It might seem frightening and omnipresent, but the truth is that potato defect is much less ubiquitous than we in the coffee industry have come to anticipate.

Once you’ve purchased your green coffee, it’s time to scale up from the sample roaster and start roasting on a production scale. James McKenney, Specialty Sales Trader & Q Grader, has 6+ years of experience working at roasteries of all sizes, ranging from small startups to national roasters, and he’s here to share his experience of scaling up from sample to production roaster.

During the coffee roasting process, there’s a lot happening chemically inside each bean. The resulting flavor profile is the product of all those chemical reactions; but what’s actually happening? And how does it impact the flavors we taste?