While writing about blending that sometimes happens at origin (at the mill or exporter) I got to use the phrase "bimodal distribution". Finding a raw coffee with a bimodal distribution on some physical attribute (color of the raw seed is easiest to spot) is a good indication that some kind of blending happened before the coffee reached the roaster.
When you run into a coffee like that, it can be interesting to sort a sample of that back out into its constituent parts and try roasting the separate components and comparing those with the combined coffee. You'll often find that the combined coffee is superior to either selection, and doing that exercise is a good way to start busting myths that some green coffee buyers believe about excessive sorting.
