Anaerobic natural processing may sound scientific, but it's actually a game of time for coffee farmers.
They put fresh coffee cherries into sealed stainless steel tanks, forcing the sugars in the pectin to decompose in "slow motion" in an oxygen-free and low-temperature (10-15 degrees Celsius) environment. This long three-day wait allows enough time for the sweetness to penetrate into the heart of the beans, which are then spread out on racks to sun-dry. Anaerobically natural processed beans often have an astonishingly rich sweetness and exceptionally harmonious and balanced flavor layers.