A winnower blows air through grain to strip out the chaff — one of humanity’s oldest processing machines, running from hand baskets tossed in the wind to modern aspiration cleaners. The principle never changed: a controlled airstream lifts light impurities while sound, dense kernels fall through. Chocolate makers use the same trick, winnowing roasted cocoa beans to separate shell and some germ. Good winnowing is quality control’s first step, pulling out dust, husks, light impurities, and insect-damaged grain before milling, and modern plants fold aspiration into cleaning lines alongside sieves and destoners for complete grain preparation.