Waste and Sustainability.
A kitchen that weighs its bins for a week usually finds that the biggest waste is not trim but what guests leave and what was cooked and never sold.
UNEP's Food Waste Index estimates that about 1.05 billion tonnes of food were wasted worldwide in 2022 — some 60 % in homes, 28 % in food service and 12 % in retail — on top of the losses between farm and shop. For a restaurant, waste falls into four streams: spoilage (stock that went off before use — poor rotation, over-ordering, bad storage, XIII.2), preparation waste (peel, bone, trim — partly unavoidable, partly usable, XXXI.4), overproduction (food cooked ahead and never sold) and plate waste (what guests leave). Each has its own causes and fixes, which is why the first step is to measure them separately.
A waste audit is simple: a bin or caddy for each stream, weighed and recorded every day for a week or two, with the reason for anything thrown away. The fixes follow. Spoilage: first in, first out (FIFO) rotation with dated labels, smaller and more frequent orders, a well-run fridge. Preparation: better yields, by-products into stocks, sauces and staff meals. Overproduction: forecasting from past covers, batch cooking through service rather than all at once, a flexible menu for leftovers (XXIII.7). Plate waste: portions matched to appetite, garnishes people eat, sides offered rather than imposed. What cannot be avoided goes to food banks where safe, then to animal feed or compost, then to energy — and only last to landfill. The workshop audits a week.
Below: a week's food waste for the covers you choose, from the plate waste, preparation trim and overproduction you set (teaching purchases of 0.45 kg of food per cover at an average 4 ¤ per kg), by stream, with its weight, share of purchases and cost.
- Name the four waste streams.
- Run a waste audit.
- Choose fixes for each stream.
- Use the food waste hierarchy.
Weigh it, then cut it
A kitchen of 1 000 covers a week with 60 g of plate waste, 10 % trim and 6 % overproduction throws away about 141 kg a week, some 29,328 ¤ a year at these illustrative prices. Halving the plate waste and cutting overproduction to 2 % brings it to about 93 kg — a saving of about 9,984 ¤ a year, before counting the by-products put to use and the labour of handling waste.
A one-week audit: set out separate, labelled caddies for spoilage, preparation, overproduction and plate waste; weigh each at the end of every shift and log it with the main items and reasons; total and cost them at the week's end; pick the largest stream and change one thing (portion size, a prep list from forecast covers, FIFO labels); repeat the audit a month later. Share the results with the team — waste falls fastest when cooks see the numbers.
Weigh everything your household throws away from the kitchen for a week, sorted into spoiled, trimmings, cooked-but-uneaten and plate leftovers. Which was biggest?
Terms
- Waste audit
- Weighing waste by stream to find its causes.
- FIFO
- First in, first out: use older stock first.
- Overproduction
- Food cooked and never sold.
- Food waste hierarchy
- Prevent, redistribute, feed animals, compost or energy, landfill last.
Sources
- UNEP, Food Waste Index Report 2024: about 1.05 billion tonnes of food wasted in 2022 — about 60 % in households, 28 % in food service and 12 % in retail — beside the roughly 13 % lost between harvest and retail (FAO); food loss and waste together account for about 8–10 % of global greenhouse-gas emissions.
- A teaching value chosen for the course: the right order of magnitude and shape, not a measurement of a particular food.