Long-term growing contracts promise predictable ingredient costs, yet most restaurants struggle with hidden expenses that quietly erode profits. Many operators focus solely on the contract price while overlooking storage fees, quality loss, and financing costs. This oversight creates a margin calculation that's completely divorced from reality.
What is a long-term growing contract?
Contract growing involves agreements with producers for delivery of seasonal ingredients like potatoes, vegetables, or fruit at predetermined prices. You'll typically pay upfront or through installments, securing guaranteed delivery at locked-in rates.
💡 Example:
You sign a contract for 5,000 kg of potatoes:
- Contract price: €0.85/kg
- Market price season: €1.20/kg
- Advance payment: 50% = €2,125
Savings: €0.35/kg = €1,750 advantage
Calculate your actual purchase price
Your true purchase price extends far beyond the contract amount. Here's what actually impacts your costs:
- Contract price per kg (base payment to grower)
- Financing costs (interest lost on advance payments)
- Storage costs (refrigeration, warehouse space)
- Quality loss (spoilage, deterioration, waste)
💡 Example calculation:
5,000 kg potatoes, 6-month contract:
- Contract price: €0.85/kg
- Financing costs: €2,125 × 5% × 0.5 year = €53
- Storage costs: €200/month × 6 = €1,200
- Quality loss: 8% = 400 kg
Total costs: €4,250 + €53 + €1,200 = €5,503
Actual price: €5,503 / 4,600 kg usable = €1.20/kg
Compare with market price for margin impact
Calculating your margin accurately requires comparing your actual purchase price against current market alternatives. The gap between these figures reveals your real advantage or disadvantage per ingredient. I've seen this mistake cost the average restaurant EUR 200-400 per month because they price menu items based on contract costs alone, not true expenses.
⚠️ Note:
Always calculate with your actual usage, not the contracted quantity. Quality loss and waste reduce your available inventory.
Adjust your food cost calculation
Your cost price calculations should reflect actual purchase prices, never just contract amounts. This approach provides an honest view of your per-dish profitability.
💡 Example food cost:
Fries portion of 300 grams:
- Potatoes: 0.3 kg × €1.20 = €0.36
- Other ingredients: €0.40
- Selling price: €4.50 incl. VAT = €4.13 excl. VAT
Food cost: (€0.76 / €4.13) × 100 = 18.4%
Monitor throughout the season
Track monthly performance of your contracts against fluctuating market prices. Market conditions shift constantly, so your financial advantage changes with them.
- Check market prices with your supplier
- Calculate your actual savings or extra costs monthly
- Adjust menu price if the disadvantage becomes too large
How do you calculate margin with contract growing? (step by step)
Calculate all actual costs
Add up: contract price + financing costs + storage + quality loss. Divide by actual available quantity to get your true purchase price per kg.
Compare with market price
Check what you would otherwise pay for the same product. The difference between your actual purchase price and market price is your advantage or disadvantage per kg.
Use in food cost calculation
Calculate your dish cost price with the actual purchase price, not the contract price. This shows you your true margin and lets you set prices correctly.
✨ Pro tip
Compare your all-in contract costs against market prices every 30 days during growing season. If your contract runs €0.15/kg above market for 8 consecutive weeks, immediately adjust menu pricing to protect margins.
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
Should I include financing costs in my purchase price?
Absolutely. Advance payments mean you're either losing potential interest income or paying loan interest. These represent real costs that directly increase your effective purchase price.
What if the market price drops below my contract price?
You'll face a temporary disadvantage on that ingredient. Either compensate by slightly increasing prices on other dishes or accept lower margins on items containing that ingredient until market conditions shift.
How do I estimate quality loss with contract growing?
Request historical data from your grower as a starting point. Typical loss ranges: 5-10% for potatoes, 10-15% for leafy greens, 3-8% for root vegetables. Track your actual losses after initial deliveries to refine estimates.
Can I combine contract growing with spot purchases?
Many restaurants use 60-70% contract purchases for price stability and 30-40% spot buying to capitalize on market lows. Calculate each stream separately for accurate margin tracking.
When is contract growing financially worthwhile?
Contract growing pays off when your total actual purchase price consistently stays below average market rates. Review this monthly, not just at contract signing.
How do I handle seasonal price swings in my calculations?
Build a 12-month rolling average of market prices for comparison. This smooths out seasonal spikes and gives you a realistic baseline for evaluating contract performance.
📚 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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