Grain Cleaning Recovery & Clean Out-Turn

Cleaning recovery is the share of raw harvested grain that remains as clean, marketable grain after the chaff, dust, weed seeds, soil and broken or shrivelled grain are removed. Because cleaning takes out that foreign matter, the clean out-turn weighs less than what came off the field — and recovery is the percentage that survives the cleaning step.

Enter the raw grain weight and the foreign-matter fraction, and it returns the clean grain (out-turn), the waste removed, the recovery percentage and the raw figure for reference. So 1000 kg of raw grain with 8% foreign matter cleans down to about 920 kg of clean grain, 80 kg of waste, and a 92% recovery.

Foreign matter (or dockage) is everything that isn't sound, whole grain of the crop: chaff, straw and husk fragments, dust and soil, stones, weed and other-crop seeds, insect-damaged kernels, and broken or shrivelled grain. Buyers measure it because it adds weight without value and can carry moisture, pests and contaminants into storage.

Clean grain grades higher and meets market and milling specifications, so it fetches a better price and isn't docked or rejected. It also stores far more safely — chaff, dust and broken kernels hold moisture, attract insects and create hot spots, while weed seeds can germinate or contaminate seed lots. Cleaning is cheap insurance for both price and shelf life.

Recovery = (raw weight − foreign matter removed) ÷ raw weight × 100, where the foreign matter removed is the raw weight times the foreign-matter fraction. Equivalently, recovery ≈ 100% minus the foreign-matter percentage. The lower the dockage, the higher the recovery and the closer the clean out-turn is to the raw weight.

It varies widely with crop, harvest method and conditions — combine-harvested cereals might carry a few per cent, while hand-threshed or poorly cleaned lots can run much higher. Market standards often set a maximum (commonly in the low single digits) above which the grain is downgraded or docked, which is exactly why pre-sale cleaning pays.

Clean grain is the out-turn you can sell or store. Waste is the foreign matter removed during cleaning. Recovery % is the clean grain as a share of the raw weight — your cleaning efficiency. Raw echoes the starting weight so you can see how much the lot shrank and value the clean fraction correctly.

Cleaning mainly removes physical foreign matter, not bound moisture in the grain — that's the job of drying. But because chaff, green material and broken kernels often carry extra moisture, removing them does lower the average moisture and the spoilage risk of the lot. For storage, clean and dry to the safe-storage moisture for your crop.

They're solid planning figures based on the foreign-matter fraction you enter — sample and assess the lot carefully for the best estimate. Real cleaning also loses a little sound grain to the screenings and gains nothing back, so treat recovery as an upper guide and confirm with weighed clean and waste streams when you can.

Yes — it works for wheat, rice/paddy, maize, pulses, oilseeds and more; just enter the raw weight in any consistent unit (kg, quintal, tonne, bag) and the foreign-matter fraction. The proportion-based logic is the same across crops, so the clean out-turn and recovery scale from a sample to a full lot.