Invoice price isn't plate cost
Trim and cooking loss mean you buy more than you serve. A simple yield test shows what a portion really costs, and it often changes the price of every protein dish.
A supplier invoice tells you what you paid per kilo. It doesn't tell you what a portion on the plate costs. Between the two sit trimming, cooking loss and prep waste, and they can easily add a quarter to the real cost of a dish.
The brisket example
You buy beef brisket at €11.20 per kg. You trim it, smoke it and slice it. Out of every raw kilo, about 730 grams of cooked meat reaches the plate. That is a yield of 73%.
| 150 g cooked portion | Costed from invoice | Costed from yield |
|---|---|---|
| Price per kg used | €11.20 | €11.20 ÷ 0.73 = €15.34 |
| Cost of 150 g | €1.68 | €2.30 |
| Under-costed by | €0.62 a portion (27%) |
If the menu price was set from the invoice price, every brisket dish is earning less than you think. Sell 400 portions a month and that is nearly €250 that never shows up until the month closes.
You don't buy 150 grams of brisket. You buy 205 grams and serve 150.
How to run a yield test
- Weigh the product as it arrives from the supplier.
- Trim it the way your kitchen normally does, and weigh it again.
- Cook it to your standard and weigh what is ready to portion.
- Divide the final weight by the starting weight. That is the yield.
- Repeat it two or three times on different deliveries and use the average.
Do it first for your most expensive ingredients, usually meat and fish. A small difference in yield on a €20 per kg product matters far more than on onions.
Where else yield hides
- Vegetables and fruit. Peeling, coring and trimming. Avocado and pineapple lose a lot.
- Sub-recipes. A sauce made in a 5-litre batch loses some to the pan and the containers.
- Frying oil and portioning. Small losses that add up over hundreds of covers.
Once the yield is in the recipe, every new invoice price flows through correctly. FoodNormIQ calls this the normative cost: the cost of what you really need to buy to serve one portion. It recalculates it each time a supplier price changes.