Ratio of sand, silt and clay affects drainage Food production: Drying cocoa beans in the sun or over a wood fire, for example Topography: The elevation, slope, and orientation of a plant Neighboring plants: Adjacent crops that compete for water or nutrients Agricultural practices: Such as when and how vines are pruned and grapes are harvested Insects: mites and aphids that eat hop plants and others Microbes: The bacteria and yeast and other fungi on grapes To see if they could trace a coffee to its origin using the coffee’s blend of trace elements, Ehleringer and his team recently measured the concentrations of about 40 trace elements in more than four dozen samples of roasted arabica coffee beans from 21 countries.