Seasonal products like asparagus, strawberries or game often have short shelf lives and high purchase prices. Wasting these products can quickly eat into your profit. Here's exactly how to calculate what waste costs you and minimize it.
Why seasonal products pose extra risk
Seasonal ingredients are often 2-3x more expensive than their regular alternatives. White asparagus costs €12-18 per kilo, while green asparagus costs €4-6 year-round. With fresh products like strawberries or mushrooms you've got only 2-3 days before they become unsellable.
⚠️ Note:
With seasonal products your waste percentage is often higher than with standard ingredients. Plan for 15-25% instead of the usual 5-10%.
The waste cost formula
For each seasonal ingredient you calculate:
Waste costs = Purchase value × Waste percentage × Number of cycles per season
The number of cycles matters because with short shelf lives you need to order more frequently. If you get fresh products 3x per week instead of 1x, you've got 3x more waste risk.
💡 Example:
You buy 2x per week 5 kg white asparagus for €15/kg during 8 weeks of asparagus season:
- Total purchase: 5 kg × €15 × 2x per week × 8 weeks = €1,200
- Waste: 20% (short shelf life)
- Waste costs: €1,200 × 0.20 = €240
You lose €240 on asparagus you throw away - that's 16 kg of product!
Different types of waste
With seasonal products you've got three sources of waste that need separate calculations:
1. Date-related waste
Products that expire before you use them. This is the biggest cost item with seasonal products.
2. Quality loss
Products that are still within the date but don't look good anymore. Think of limp asparagus or soft strawberries.
3. Overproduction
You've prepared too much for the expected number of guests. With expensive seasonal products this costs extra.
💡 Example calculation per type:
Restaurant with strawberry dishes in June (4 weeks):
- Date waste: €180 (15% of €1,200 purchase)
- Quality loss: €60 (5% of purchase)
- Overproduction: €120 (10% of purchase)
Total waste costs: €360 in 4 weeks
Calculate impact on your food cost
You need to include waste costs in your cost price calculation. Otherwise you'll price too low and lose money on every dish. Most kitchen managers discover this too late - after a full season of losses.
Actual cost price = Ingredient purchase price × (1 + Waste percentage)
💡 Example cost price adjustment:
Strawberry dessert with 150g strawberries per portion:
- Purchase price strawberries: €8/kg
- Waste: 20%
- Actual cost price: €8 × 1.20 = €9.60/kg
- Per portion: 0.15 kg × €9.60 = €1.44 instead of €1.20
Difference: €0.24 per portion - at 100 portions per week = €24 extra costs
Create seasonal planning
Make a plan for each seasonal product with expected volumes and waste percentages. Use data from last year as a basis, but adjust for this year.
- Week 1-2: Order cautiously (no routine yet)
- Week 3-6: Optimal period (ideal ratio of demand/supply)
- Week 7-8: Wind-down phase (less demand, higher waste)
⚠️ Note:
In the final weeks of a season, plan for 30-40% waste. Guests are tired of the product and quality declines.
Daily control routine
With seasonal products you check every day:
- What's left from yesterday?
- Which products need to be used today?
- How much do you expect to sell tonight?
- What can you still process in daily specials?
Note daily what you throw away and why. This gives you data for next season.
Tools for seasonal products
Food cost calculators can help you set the waste percentage for each seasonal product. Many apps automatically factor this into your cost prices, so you don't forget to pass these costs on.
You can also set alerts for products that are about to expire, so you can still process them in daily specials or staff meals.
How do you calculate waste costs? (step by step)
Register all waste for 2 weeks
Note daily what you throw away from seasonal products and why (date, quality, overproduction). Weigh or count the quantities and note the purchase value.
Calculate your waste percentage per product
Divide the discarded value by the total purchase value and multiply by 100. This gives you the waste percentage for that specific seasonal product.
Adjust your cost prices with waste factor
Multiply your purchase price by (1 + waste percentage). Use this adjusted price in your food cost calculations for all dishes with this ingredient.
✨ Pro tip
Track waste costs daily for each seasonal product during the first 2 weeks of the season. This gives you accurate data to adjust your ordering quantities before losses pile up.
Calculate this yourself?
In the KitchenNmbrs app you can do this in just a few clicks. 7 days free, no credit card.
Was this article helpful?
Frequently asked questions
Should I include waste in my cost price calculation?
Yes, absolutely. Waste is a real cost item that eats into your profit. If you don't factor it in, you'll lose money on every dish without realizing it.
What's a normal waste percentage for seasonal products?
For seasonal products with short shelf lives, plan for 15-25% waste. With regular products 5-10% is normal, but seasonal products are more sensitive.
How do I prevent waste with unpredictable demand?
Buy more frequently in smaller quantities, even if you pay slightly more per kilo. Better to pay 5% more than throw away 20%. Also create flexible daily specials to move excess products.
Should I use different waste percentages per week?
Yes, that's smart. In the first and last weeks of a season waste is often higher. Adjust your purchasing strategy and cost prices accordingly.
📚 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.
Make food waste measurable and manageable
Every kilo you throw away is lost margin. KitchenNmbrs connects your inventory to your recipes so you can see exactly where waste occurs — and how much it costs. Try it free.
Start free trial →