Post-Harvest Weight Loss: How Much Your Produce Sheds Per Day, by Category

Every trader knows produce "dries out". Far fewer have ever put a number on it — and the numbers are worth putting, because in a business of thin margins, weight is money. A crate you bought at 20 kg and sell across three days is not a 20 kg crate on day three. You paid for water that has since left the building.

Here is what dehydration actually looks like per category, why the spread between categories is the whole game, and how to measure yours instead of averaging everyone else's.

Daily weight loss by category

These are working reference rates for produce held under good storage conditions (right temperature, decent humidity). They are the defaults we ship in ShelfLifePro's dehydration model, and they square with the post-harvest handling literature — but the honest caveat comes first: your sheds, your airflow, your packing all shift these. Measure your own; use these to know what "normal" roughly looks like:

The spread is the story: herbs lose weight fifteen times faster than potatoes. Any flat "produce shrinkage" percentage applied across the shop is wrong for every single category — too alarmist for onions, dangerously relaxed for coriander.

And these are good-storage numbers. Put the same crate under a warm tin shed in May and the rates multiply — a useful rule of thumb is that loss roughly one-and-a-half-times for every meaningful step away from optimal temperature, and that's before wilting makes the stock visually unsellable at any weight.

What this does to your money

Take a 20 kg crate of spinach bought at ₹8/kg (₹160 a crate) and sold at ₹15/kg:

• Sold same day: ~20 kg sellable → ₹300 revenue.
• Sold on day 2: ~19.2 kg → ₹288. You silently donated ₹12 — 4% of revenue — to the atmosphere.
• Sold on day 3 (if it still looks sellable): ~18.5 kg → ₹277, and realistically a chunk is now wilt-trim on top.

Scale that across every crate of every fast-losing category, every day, and dehydration is frequently a bigger drain than outright dumping — because dumping you notice, and this you don't. India's overall post-harvest fruit-and-vegetable loss is commonly put at 30–40%; the dramatic photos are of rotting lots, but a fat slice of that number is exactly this: weight that left quietly, a percent or two at a time.

Measuring yours: the weigh-in habit

The reference table above is a starting point. The trade-changing move is replacing it with your numbers:

• Weigh consignments in. Expected kg (what you bought) vs actual kg on your scale, recorded per batch — receiving discrepancies and dehydration are different problems, and this separates them on day one.
• Re-weigh on a cadence for fast-losing categories. A daily spot-weigh of one crate per batch of greens is enough to draw the curve.
• Log loss percent per check, not just weight. 486.5 kg against an expected 488.0 is a 2.7% conversation; raw kilograms are just a number.
• Let the loss rate drive the clearance decision. When a batch's measured curve says it won't clear at current pace before it's unsellable, the discount ladder should start now, at hours-level granularity for greens — not after the evening walk-through.

The tie-in, earned

This is one of the two pillars we built the fresh-produce edition of ShelfLifePro around: weigh-ins per consignment with expected-vs-actual and loss percent per check, and an hour-level clearance ladder for the categories at the top of that table. The reference rates above ship as editable defaults — the product's job is to replace them with your measured reality, crate by crate, and to make sure the spinach that dies tonight is the spinach the market sees first.