Most chefs think dried legumes are dirt cheap at €3 per kilo, while canned beans feel expensive at €0.89. But you're comparing dry weight to ready-to-eat weight. Once you cook those dried beans, the math flips completely.
Why dried products are confusing
You buy dried beans for €3 per kilo. That seems dirt cheap. But you don't serve dry beans. After soaking and cooking, that same kilo often weighs 2.5 to 3 kilos. Your real cost per kilo of cooked beans is therefore much higher.
⚠️ Watch out:
Many kitchens calculate based on dry weight and underestimate their real costs. This can throw off your food cost by 5-10%.
The three steps to real portion costs
For an accurate calculation you need three numbers: purchase price per kilo dry, the cooking yield (how many times heavier it becomes), and your desired portion size cooked. Most kitchen managers discover too late that they've been calculating their legume costs wrong for months.
💡 Example - Chickpeas:
You buy dried chickpeas for €2.80 per kilo.
- After soaking: 1 kg becomes 2.2 kg
- After cooking: 2.2 kg becomes 3.1 kg total
- Portion size: 120 grams cooked
Cost per portion: €2.80 / 3.1 kg × 0.12 kg = €0.11
Cooking yields of popular legumes
Each product has a different cooking yield. Use these figures as a starting point, but always test your own supplier:
- Lentils (red): 1 kg dry → 2.8 kg cooked
- Lentils (green/brown): 1 kg dry → 2.5 kg cooked
- Chickpeas: 1 kg dry → 3.1 kg cooked
- Black beans: 1 kg dry → 2.7 kg cooked
- White beans (cannellini): 1 kg dry → 2.9 kg cooked
- Kidney beans: 1 kg dry → 2.6 kg cooked
💡 Example - Comparison:
Red lentils vs. chickpeas at €3.00/kg dry and 100g portion:
- Red lentils: €3.00 / 2.8 kg × 0.10 kg = €0.11 per portion
- Chickpeas: €3.00 / 3.1 kg × 0.10 kg = €0.10 per portion
So chickpeas are slightly more economical per portion despite longer cooking time.
Including energy and labor
Besides the product itself, dried legumes cost energy and time. Chickpeas need 8-12 hours soaking and 60-90 minutes cooking. Add 10-20 cents per portion for gas and labor.
⚠️ Watch out:
Don't forget to factor in salt. Dried beans absorb a lot of salt during cooking - often 8-12 grams per kilo of cooked product.
Canned vs. dried: the real comparison
Canned beans seem more expensive, but they're ready to use. For a fair comparison, calculate the cost per kilo of ready-to-use product:
💡 Example - Cost comparison:
Chickpeas, 1 kg ready to use:
- Dried: €2.80 / 3.1 + energy/labor = €1.10 per kg
- Canned (400g = 240g drained weight): €0.89 / 0.24 kg = €3.71 per kg
Dried is 3x cheaper, but costs time and planning.
Planning and stock rotation
Dried products have a long shelf life (1-2 years), but cooked legumes must be used within 3-4 days. Plan your purchases based on your weekly consumption, not on stock discounts.
How do you calculate portion costs? (step by step)
Measure your supplier's cooking yield
Cook 500 grams of dried product according to your standard recipe. Weigh the result after fully cooking and draining. Divide the final weight by the starting weight to get your yield factor.
Calculate the cost per kilo cooked
Divide your purchase price per kilo dry by your yield factor. At €3.00/kg dry and yield 2.8, this becomes €3.00 / 2.8 = €1.07 per kilo of cooked product.
Calculate portion costs including extras
Multiply the cost per kilo by your portion weight in kilos. Add 10-20 cents for energy, salt and labor. This is your real cost per portion for your food cost calculation.
✨ Pro tip
Recalculate your cooking yields every 6 months with fresh batches. Beans older than 18 months can reduce your yield by 15-20%, silently eating into your 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 the soaking water in the cooking yield?
No, only count the final weight after cooking and draining. You throw away the soaking water, so it doesn't count toward your portion weight.
Can I use the yields from this article directly?
Use them as a starting point, but always test your own supplier. Quality and origin affect cooking yield by 10-20%.
How do I calculate the energy costs for cooking?
Budget approximately €0.15 per hour of gas use for a large pot. At 90 minutes cooking for 3 kg product, that's €0.08 per kilo cooked.
Is dried always cheaper than canned?
Usually yes, 2-4x cheaper per kilo ready to use. But you need to factor in labor costs and planning in your decision.
📚 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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