DULDAM

A thin margin with a predictable leak

Contract catering runs on margins in the 3% range. In the first half of 2026 the three listed Korean caterers reported operating margins between 2.0% and 6.9%, which leaves less than KRW 200 on a KRW 5,000 lunch. That margin leaks from the same three places every day: food cooked but never served, food left on the serving line, and food left on the tray.

Most waste campaigns start at the tray-return counter. By then the food has already been bought, washed, cooked and served, so the money is gone. We measure the three points separately, because each one recovers a different kind of cost.

The number we took out

Cutting plate waste only saves the disposal fee: about KRW 70,000 a month at an 800-meal site. Making 40 fewer meals a day saves about KRW 2.2 million in ingredients. That is why 97% of the effect sits in production, and why the pilot puts its effort into measurement that a dietitian will trust enough to change the plan.

There was a tempting shortcut. Convert the drop in plate waste into portions and multiply by ingredient cost, and you get an impressive KRW 1.86 million a month. It is food the caterer has already paid for, so it never comes back. We left it out of every total, and the simulator flags it as a common error.

Two changes that cost nothing

Neither change needs new equipment. Rice moves later in the serving line, so diners see the whole meal before deciding how much staple food to take. And one sign changes: instead of "Please don't leave food", it says "You can always come back for more", which makes a smaller first serving feel safe.

Making yes easy

An earlier version of the offer charged a small fee per site. We dropped it. The pilot is now free, the caterer gives one site and about 26 minutes of staff time a day, and the success criteria are agreed before it starts: plate waste per person down at least 10%, lower production surplus, and no rise in stock-outs or complaints.

To make the first meeting concrete, I built the DULDAM website, with an AI diagnosis that turns one sentence about a cafeteria into simulator inputs, and a desktop simulator for Windows and Mac that splits disposal savings from ingredient savings.

Visit duldam.lovable.app(opens in a new tab)