Your busiest Saturday night and you're down to three empty kegs—but your supplier needs eight empties before they'll drop off Monday's beer delivery. Most bars guess at their cask inventory needs, either burying cash in unnecessary deposits or scrambling for empties during peak service. One simple formula based on weekly sales eliminates this guesswork.
What is cask inventory and why does it matter?
Cask inventory covers all the empties you rent from suppliers—bottles, kegs, and crates. You'll fork over deposits per piece (around €0.10 for bottles, €30 for beer kegs) that come back when you return them.
But here's the catch: not enough empties means no deliveries. Too many empties means your cash sits locked in deposits you're not using.
The basic formula for cask calculation
Your cask inventory math needs three key numbers:
- Expected sales per week (in euros)
- Percentage of beverages from total sales (usually 25-40%)
- Average cask value per euro of beverage sales
💡 Example calculation:
A café pulling €8,000 weekly:
- Beverage sales: 35% of €8,000 = €2,800
- Cask value per €100 beverage sales: €12 (mix of beer/wine/soft drinks)
- Total cask value: €2,800 ÷ 100 × €12 = €336
You need €336 worth of cask inventory per week.
Cask value per beverage type
Different drinks pack different cask costs. Standard breakdowns look like:
- Beer (bottles): €0.10 per bottle, roughly €8 cask per €100 beer sales
- Beer (draft): €30 per 50L keg, roughly €6 cask per €100 draft sales
- Wine (bottles): €0.25 per bottle, roughly €2 cask per €100 wine sales
- Soft drinks (bottles): €0.15 per bottle, roughly €12 cask per €100 soft drink sales
⚠️ Note:
These numbers are averages. Your real cask costs depend on supplier deals, drink mix, and pricing. Track actual cask usage for 2-3 weeks to nail down your specific ratio.
Accounting for seasonal fluctuations
Cask needs swing with the seasons. Summer drives beer and soft drink sales higher (more cask per euro), while winter shifts toward wine and hot drinks (less cask per euro).
One of the most common blind spots in kitchen management happens when operators forget to adjust their cask calculations for these predictable seasonal swings. You'll end up with too much inventory in winter or scrambling for empties during summer rushes.
💡 Seasonal example:
Terrace season (May-September):
- 60% beer, 25% wine, 15% soft drinks
- Cask value: €14 per €100 beverage sales
Winter season (October-April):
- 40% beer, 50% wine, 10% hot beverages
- Cask value: €8 per €100 beverage sales
Buffer and delivery frequency
Beyond weekly usage, you need safety stock. Buffer size depends on how often deliveries show up:
- Daily delivery: 20% buffer
- 2x per week delivery: 50% buffer
- Weekly delivery: 100% buffer (= 2 weeks inventory)
The complete formula becomes: Weekly cask consumption × (1 + buffer%) = Total cask inventory needs
💡 Practical example:
Café with weekly delivery:
- Weekly cask consumption: €336
- Buffer for weekly delivery: 100%
- Total cask inventory needs: €336 × 2 = €672
This equals €672 in deposits tied up in cask inventory.
Digital tracking of cask consumption
Systems like KitchenNmbrs let you monitor weekly beverage sales and automatically calculate cask inventory requirements. You'll instantly see if you're carrying excess or insufficient cask inventory.
How do you calculate your cask inventory needs? (step by step)
Determine your weekly beverage sales
Get your cash register data from the past 4 weeks. Add up all beverage sales and divide by 4. This gives you your average weekly beverage sales in euros.
Calculate your cask value per €100 beverage sales
Track all your cask consumption for one week (number of bottles × deposit per bottle). Divide this by your beverage sales that week × 100. This gives you your personal cask ratio.
Calculate total cask inventory needs including buffer
Multiply your weekly beverage sales by your cask ratio. Add your buffer based on delivery frequency (20% for daily, 100% for weekly).
✨ Pro tip
Track your actual cask turnover during your 3 busiest weeks of the year, then add a 25% buffer to that peak number. This prevents expensive emergency cask hunting during unexpected volume spikes.
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 much deposit money should I typically have tied up in cask inventory?
Most bars see 4-8% of monthly sales locked in deposits. A bar hitting €20,000 monthly would have €800-1,600 tied up in cask deposits. Draft beer operations usually run higher percentages.
What happens if I run short on cask inventory and suppliers can't deliver?
You'll scramble for cask from backup suppliers at premium rates—sometimes 3-4x normal deposit costs. Some suppliers also hit you with restocking fees when deliveries get canceled due to missing empties.
Can I deduct cask deposits as business expenses?
Deposits aren't deductible since they're refundable security payments. But you can write off actual cask damage or permanent losses as operating expenses.
Should I adjust cask calculations for special events or holidays?
Absolutely. Major events can double normal beverage sales, requiring proportional cask increases. Plan 2-3 weeks ahead since emergency cask sourcing costs way more than standard deposits.
📚 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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