The supplier invoice says CHF 28.00 per kilo of beef rump, 180 grams go on the plate, so the portion costs CHF 5.04. That is how the sum appears in a great many costings. It is wrong. Between the invoice and the plate part of the goods disappears, first during trimming and then again during cooking. This article works through the whole route. And it says where the percentages for it should come from, because in Switzerland you cannot simply copy them out of a table. How the food cost itself is calculated is in the article calculating the food cost percentage.
Why does the purchase price not match the food cost?
Because you buy gross weight and sell net weight. The supplier invoice carries a price for the goods as they are delivered. What lies on the plate is something else: trimmed, peeled, boned, cooked.
Two losses sit in between, and they happen one after the other.
- Trim loss happens during preparation. Sinew, fat, bone, peel, stalks, offcuts. It is visible, because it lands in the bin.
- Cooking loss happens during cooking. Water and fat come out and the piece gets lighter. It is invisible, because nothing is left that you could weigh. That is exactly why it gets forgotten more often.
The yield is the share of the goods you bought that actually reaches a plate. As long as that factor is missing, the food cost is too low, the food cost percentage looks better than it is, and the selling price was built on a figure that never existed.
What does not belong here: the goods a business loses in other ways. That is shrinkage, and it belongs somewhere else in the calculation.
How do you calculate the yield and the price of the usable quantity?
With two divisions.
Yield = net weight ÷ gross weight Price of the usable quantity = purchase price ÷ yield
Worked through on a beef rump at CHF 28.00 per kilo gross. Every percentage in the example is one we set ourselves, not a guide value.
Step 1: trim and weigh. A kilo gross gives 780 g after trimming.
Trim yield: 780 ÷ 1,000 = 0.78 = 78%
Step 2: cook and weigh again. The 780 g become 624 g of ready-to-eat meat.
Cooking yield: 624 ÷ 780 = 0.80 = 80%
Step 3: the overall yield. Of a kilo purchased, 624 g reach the plate.
Overall yield: 0.78 × 0.80 = 0.624 = 62.4%
Step 4: the price of the ready-to-eat quantity, and what the portion costs.
CHF 28.00 ÷ 0.624 = CHF 44.87 per kilo 180 g ready to eat: 0.180 × CHF 44.87 = CHF 8.08
You cost with the 44.87, not with the 28.00 from the invoice.
The 180 g are the quantity served, not the quantity that goes into the pan. If your recipes are kept in raw weights, the yield applies at a different point. It must appear exactly once; otherwise you count the loss twice.
Why are trim loss and cooking loss multiplied and not added?
Because the second loss does not act on the kilo you bought, it acts on what the first one left. The 20 percent cooking loss refers to the 780 g of trimmed meat, not to the kilo. So 0.78 × 0.80, and not 100 minus 22 minus 20.
The same beef rump, the same 180 g portion, one correct way of calculating it and three wrong ones:
| Calculation | Yield | Ready-to-eat price | Meat per portion |
|---|---|---|---|
| Yields chained (correct) | 62.4% | CHF 44.87/kg | CHF 8.08 |
| Loss percentages added (22% + 20%) | 58% | CHF 48.28/kg | CHF 8.69 |
| Trim loss only, cooking loss forgotten | 78% | CHF 35.90/kg | CHF 6.46 |
| Invoice price used directly | none | CHF 28.00/kg | CHF 5.04 |
Adding is off, but only slightly: 61 centimes too much per plate. That is an error in the safe direction, and day to day it barely shows.
The second error is the expensive one. Costing with the invoice price comes out CHF 3.04 short per plate. On an evening with 60 plates that is 3.04 × 60 = CHF 182.40, every service, and nobody sees it, because the costing looks clean taken on its own. Anyone who counts the trim loss and forgets the cooking loss comes out CHF 1.62 short per plate, and still thinks the figure is right.
What a corrected food cost does to the percentage can be checked directly with our free food cost calculator. How the figure turns into a selling price is in the article pricing a dish.
Where do you get your yield figures?
From your own kitchen. Not from a table.
There is no freely available, reliable Swiss yield statistic. The foreign yield tables you find online are made for other cuts, other trimming standards and other suppliers. They are not wrong, they simply do not apply to your business. The yield depends on the quality of the delivery, on the cut, on the season, on the equipment and on how carefully the trimming is done. Two kitchens working the same recipe arrive at different figures, and both are right.
So a yield test of your own replaces the table. It takes a few minutes per item:
- Weigh the delivery unit gross, exactly as it arrives.
- Trim the way you always do. Not more carefully because something is being measured, or you end up with a figure the service will never reach.
- Weigh the trimmed quantity. Yield = net ÷ gross.
- For the cooking loss, weigh a typical batch before and after cooking, with the same method and the same core temperature as in service.
- Measure three times on different days and take the mean. A single measurement is a random figure.
- Note the date, the supplier and the quality. The yield moves with season and origin, and without that note nobody knows in six months what the figure applied to.
Doing this for every ingredient does not pay. Carrots for instance, purchase price CHF 2.80 per kilo, trim yield 82 percent as an example figure:
Price of the trimmed quantity: 2.80 ÷ 0.82 = CHF 3.41 per kilo Portion 120 g trimmed: 0.120 × 3.41 = CHF 0.41 instead of 0.120 × 2.80 = CHF 0.34
Seven centimes per plate. It is exactly the same calculation as on the meat, with a fraction of the effect. Start where both come together, a high price per kilo and a high loss: meat, fish, shellfish, hard cheese. On cheap vegetables a rough figure will do for now.
Which details on the packaging already help?
On packaged goods part of the yield is already declared. The Mengenangabeverordnung (MeAV, SR 941.204), the Swiss ordinance on quantity declarations, prescribes which quantity has to be stated, and it covers exactly the cases where the gross weight misleads. There is no official English version of this ordinance: the German, French and Italian texts are the binding ones, and every passage quoted below is an unofficial translation given for information.
First, the net quantity governs. Art. 3 para. 1: “In trade, the quantity of measurable goods is to be determined by weight, volume, area, length or number of items. What governs is the net quantity of a good.” And the net quantity is the “quantity of a good without its wrapping and further packaging material” (Art. 2 let. g).
Second, and more interesting for costing: where solid goods sit in liquid, the drained weight has to be declared as well. Art. 16 para. 1: “Where a solid foodstuff is in a covering liquid, the prepackage must state the drained weight in addition to the total nominal quantity.” The drained weight is the “weight of a solid good after the covering liquid has been poured off” (Art. 2 let. h), and covering liquids are “in particular water, aqueous solutions of sugar or salt, vinegar and, in the case of fruit and vegetables, fruit and vegetable juices” (Art. 16 para. 2).
So a tin of chickpeas carries a yield that nobody has to weigh:
Example: nominal quantity 800 g, declared drained weight 480 g, price CHF 2.40 On the nominal quantity: 2.40 ÷ 0.800 = CHF 3.00 per kilo On the drained weight: 2.40 ÷ 0.480 = CHF 5.00 per kilo Yield: 480 ÷ 800 = 60%
The costing price is the second one. Both figures are already printed on the tin. Nobody has to weigh that 60 percent, only divide.
Third, deep-frozen goods. Art. 17: “When stating the nominal quantity of deep-frozen goods, ice that is not part of the goods may not be included.” So the declared quantity is already calculated without that ice. What actually comes out when the goods thaw is not covered by it. The business has to weigh that itself.
The declared figure is not a free estimate either. Art. 22 para. 1 let. a: “The actual drained weight must not on average be less than the stated drained weight.” What is bound is the average, not the individual tin. For costing that is enough, because you calculate over many tins and not over one.
The limits of the packaging are reached quickly all the same. The label says nothing about the trim loss, nothing about the cooking loss and nothing about the thaw loss. What can be read off is read off. Everything else gets weighed.
This section is general information and not legal advice. What is authoritative is the text of the Mengenangabeverordnung (MeAV, SR 941.204) and guidance from the competent authorities. The passages quoted above are translations for information and have no legal force; the German, French and Italian versions are binding.
What is shrinkage and why does it not belong in the yield?
Shrinkage is goods that cost money and were never sold as a portion: spoilage, overproduction, wrongly portioned plates, breakage, losses in storage. It does not belong in the yield, because it does not belong to the recipe.
The difference is repeatability. The yield is a factor of the product: same quality, same cut, same cooking method, same result. Shrinkage is a result of how the business runs. It moves from week to week, and whoever finds the cause brings it down.
Building it into the yield anyway, by setting the percentage a few points lower as a precaution, hides an operating problem inside a recipe figure. After that the two can no longer be told apart. The food cost is roughly right, but nobody can see whether that safety margin is still needed or whether the kitchen has been working cleanly for half a year and costing too high.
The place for shrinkage is the difference between the theoretical and the actual food cost of a period. Theoretical means portions sold times the costed food cost per portion. Actual means opening stock plus purchases minus closing stock. The gap between them is the shrinkage, and it is an operating figure, not a recipe figure. That is why “shrinkage recorded” appears in the article on a good food cost percentage as a condition for a percentage being comparable at all.
A third case belongs to neither yield nor shrinkage: the buffer on a catering job. It is a surplus planned deliberately so that nothing runs out at an event, and it is carried as its own line item in the job costing (catering costing).
How do you keep yield-adjusted prices current across many recipes?
By making the yield-adjusted price the stored ingredient price instead of the invoice price. Otherwise you apply the yield again in every recipe the ingredient appears in, and start over at the next price update.
The routine that works day to day:
- Measure the yield once, per ingredient and per method of preparation.
- Calculate the yield-adjusted price per kilo and store that as the ingredient price.
- In the recipes, record the quantity that is actually served.
- When the supplier changes a price, divide the new invoice price by the same yield and replace the stored price. The yield is measured again only when the supplier, the quality or the cut changes.
A stored price of CHF 44.87 next to a supplier invoice of CHF 28.00 looks like a typo. Recording the yield and the date it was measured saves that discussion, certainly by the time a new member of staff arrives.
For simply converting portion quantities our free recipe scaler is enough.
For the rest, that is exactly what we are building Trolevo for: recipes with nested sub-recipes whose food cost rolls up automatically into one amount per portion, along with the food cost at the price you have set. Change a stored ingredient price and every recipe and every sub-recipe the ingredient sits in works with the new figure, so you see which dishes are affected. There is no separate yield field today; the yield-adjusted price is carried as the ingredient price. This helps keep the costing current across many recipes. Measuring your own yields and the pricing decision stay with the business. Trolevo is in development – get early access.
Sources
- MeAV – Mengenangabeverordnung (Swiss ordinance on quantity declarations), SR 941.204, Art. 2, 3, 16, 17 and 22 (German original; there is no official English text, and the passages quoted in this article are translations for information only and have no legal force)
The figures in the examples are illustrative and not an industry statistic. The yield figures are example values we set ourselves and not guide values; every business measures its own. This article explains costing and is not legal advice.