When roasting coffee the accidental blends sometimes turn out to be the best ones. The only bad part is that they are difficult to repeat. My most current accidental blend success is a 50/50 blend of Sulawesi Toraja grade 1 and Yemen Mohka Kadir. To make it better I broke a "rule" by roasting them together. Took them about 10 seconds in to second crack for a nice dark roast. After 36 hours of aging, yum! Very sweet and syrupy. It would probably make a good espresso as well, but I'm too busy drinking it from my pour over and my press pot to try.