Ever wondered why your food costs spiral out of control despite careful menu planning? Most chefs test new dishes but skip the crucial step of converting yield results into actual cost prices. This oversight can silently drain your profits on every plate served.
What is a yield test and why does it matter?
A yield test reveals exactly how much usable product remains after processing. You purchase 2 kg of whole fish, but filleting leaves you with just 1.1 kg of fillet. That 55% yield completely changes your real cost calculations.
💡 Example:
Testing a new fish for your menu:
- Whole dorade: 2.0 kg at €16/kg = €32.00
- After filleting: 1.1 kg fillet
- Waste: 0.9 kg (head, bones, skin)
Yield: 1.1 ÷ 2.0 = 55%
Skip the yield test? You'd price based on €16/kg and lose money. But with proper testing, you'll discover that fillet actually costs €29.09/kg (€16 ÷ 0.55).
Converting yield percentage into real cost pricing
Here's your formula for accurate post-yield pricing:
Actual cost price = Purchase price ÷ (Yield % ÷ 100)
💡 Example calculation:
Yield test results for chicken thigh:
- Purchase: €8.50/kg (whole thigh with bone)
- After deboning: 70% yield
Actual cost price: €8.50 ÷ 0.70 = €12.14/kg
⚠️ Note:
Always divide by yield - never multiply. Less product means higher cost per kilo.
Translating yield results to portion costs
Once you've completed your yield test, portion costing becomes straightforward:
- Set your portion size (like 180g fillet)
- Apply the real cost price per kilo
- Factor in remaining ingredients
- Calculate total food cost percentage
💡 Complete example:
New dish: grilled dorade (180g fillet)
- Dorade fillet: 180g × €29.09/kg = €5.24
- Vegetables and garnish: €2.10
- Oil, spices, butter: €0.85
Total ingredient costs: €8.19
At menu price €28.00 (€25.69 excl. VAT): food cost = 31.9%
Monitor yield variations across suppliers
From tracking this across dozens of restaurants, I've seen identical products deliver vastly different yields depending on supplier quality and seasonal factors.
- Test identical products from competing suppliers
- Document seasonal variations (fish fat content fluctuates monthly)
- Recalculate cost prices with supplier changes
- Archive test data for future menu revisions
Digital yield data management
Tools like KitchenNmbrs let you record yield test results per ingredient. The system automatically recalculates your true cost price and updates every recipe using that ingredient.
This eliminates manual recalculation headaches whenever your yield data shifts.
How do you process yield test results? (step by step)
Perform the yield test
Buy a representative amount of the product. Process it the way you normally would and weigh the usable end result. Calculate the yield percentage: usable weight divided by purchase weight.
Calculate the actual cost price
Divide your purchase price per kilo by the yield percentage. For example: €12/kg divided by 0.75 yield = €16/kg actual cost price. This is what your usable product actually costs.
Update your recipes and cost prices
Replace the old cost price with the new actual cost price in all your recipes. Recalculate the food cost of all dishes that use this ingredient. Check if your menu price still works with the new cost price.
✨ Pro tip
Test your yield calculations during both lunch prep and dinner rush over a 2-week period. Kitchen pressure and time constraints can reduce yields by 8-15%, affecting your true cost calculations.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
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Frequently asked questions
How often should I repeat a yield test?
Always test again with new suppliers. With existing suppliers, test at least 2x per year, because quality and size can vary by season.
What if my yield turns out lower than expected?
Then your actual cost price becomes higher and you may need to adjust your menu price or find a different supplier. A 10% lower yield means 11% higher costs.
Do I also need to yield test simple products?
Yes, for products with peels, pits, or cutting waste. Think of onions (8-12% waste), potatoes (15-20%), or fruit. For ready-made products, this isn't necessary.
What if different team members achieve different yields?
Train your team in consistent processing techniques. Use the average of multiple tests, or take the lowest yield as a starting point for safe cost price calculation.
📚 Sources consulted
- EU Verordening 852/2004 — Levensmiddelenhygiëne (2004) — Official source
- EU Verordening 853/2004 — Hygiënevoorschriften voor levensmiddelen van dierlijke oorsprong (2004) — Official source
- EU Verordening 1169/2011 — Voedselinformatie aan consumenten (2011) — Official source
- NVWA — Hygiënecode voor de horeca (2024) — Official source
- NVWA — Allergenen in voedsel (2024) — Official source
- Codex Alimentarius — International Food Standards (2024) — Official source
- FSA — Safer food, better business (HACCP) (2024) — Official source
- BVL — Lebensmittelhygiene (HACCP) (2024) — Official source
- Warenwetbesluit Bereiding en behandeling van levensmiddelen (2024) — Official source
- WHO — Foodborne diseases estimates (2024) — Official source
Food Standards Agency (FSA) — https://www.food.gov.uk
The HACCP standards shown in this application are for informational purposes only. KitchenNmbrs does not guarantee that displayed values are current or complete. Always consult the FSA or your local authority for the latest regulations.
Written by
Jeffrey Smit
Founder & CEO of KitchenNmbrs
Jeffrey Smit built KitchenNmbrs from 8 years of hands-on experience as kitchen manager at 1NUL8 Group in Rotterdam. His mission: give every restaurant owner control over food cost.
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