Your draft beer tap looks profitable until you notice the puddles under every spout and realize you're pouring money down the drain. That overflow foam, those dripping taps, and glasses sent back for being "too foamy" might seem trivial. But multiply that by 100 pours daily and you're looking at serious margin erosion.
What is spillage loss with draft beer?
Spillage loss is the difference between what you pour from the keg and what you actually sell. This happens due to:
- Glasses that overflow while pouring
- Foam that gets thrown away
- Tap drips
- Glasses returned (taste complaint)
- Tastings and samples
- Remaining liquid in lines when changing kegs
⚠️ Note:
Spillage loss of 10-15% is normal for draft beer. More than 20% means something's wrong with your tap installation or pouring technique.
How do you calculate spillage loss percentage?
You measure the difference between what comes out of the keg and what you sell:
Spillage loss % = ((Keg volume - Sold glasses × 0.25L) / Keg volume) × 100
💡 Example:
A 50 liter keg yields 180 glasses of 25cl:
- Keg volume: 50 liters
- Sold: 180 × 0.25L = 45 liters
- Spillage loss: 5 liters
Spillage loss: (5 / 50) × 100 = 10%
Factoring spillage loss into your cost price
Your purchase price per glass increases due to spillage loss. Calculate it this way:
Actual cost price per glass = Keg price / (Theoretical glasses × (100% - Spillage loss%))
💡 Example calculation:
Heineken 50L keg for €85 excl. VAT, 10% spillage loss:
- Theoretical: 50L / 0.25L = 200 glasses
- Actual: 200 × 90% = 180 glasses
- Cost price per glass: €85 / 180 = €0.47
Without spillage loss it would be €0.43 per glass. Difference: €0.04 per glass.
Impact on your pour cost
Pour cost is the drink equivalent of food cost. With spillage loss, your pour cost increases:
Pour cost % = (Actual cost price per glass / Selling price excl. VAT) × 100
💡 Pour cost comparison:
Beer selling price €2.50 incl. 21% VAT = €2.07 excl. VAT:
- Without spillage loss: (€0.43 / €2.07) × 100 = 20.8%
- With 10% spillage loss: (€0.47 / €2.07) × 100 = 22.7%
Difference: 1.9 percentage points higher pour cost
Tracking spillage loss in practice
Measure it weekly to stay on top of it:
- Count kegs: How many kegs on tap this week?
- Count sales: How many glasses of beer sold according to register?
- Calculate difference: (Kegs × 200 glasses) - Sold glasses
- Determine percentage: Difference / (Kegs × 200) × 100
⚠️ Note:
Always calculate alcoholic beverages with 21% VAT, not 9%. A beer at €2.50 incl. VAT is €2.07 excl. VAT.
Reducing spillage loss
A few practical tips to limit loss:
- Pouring speed: Pour slower, less foam
- Glass angle: Start at an angle, finish upright
- Tap temperature: 4-6°C for optimal foam
- Clean lines: Dirty lines produce more foam
- Correct pressure: Too high CO2 pressure = more foam
This is the kind of thing you only learn after closing your first month at a loss - those small percentage points matter more than you'd think. With tools like KitchenNmbrs you can calculate your actual cost price per glass including spillage loss, without having to do the math yourself.
How do you calculate spillage loss in 3 steps?
Measure your actual sales
Track for one week how many kegs you have on tap and how many glasses of beer you've sold according to the register. A standard 50L keg should theoretically yield 200 glasses of 25cl.
Calculate the spillage loss percentage
Subtract the sold glasses from the theoretical yield. Divide the difference by the theoretical yield and multiply by 100. For example: (200 - 180) / 200 × 100 = 10% spillage loss.
Adjust your cost price
Divide your keg price by the actual number of glasses instead of the theoretical number. At €85 per keg and 180 actual glasses: €85 / 180 = €0.47 per glass instead of €0.43.
✨ Pro tip
Track spillage loss by individual tap for 2 weeks straight - you'll discover which lines need cleaning or pressure adjustment first. One problematic tap can skew your entire beer cost calculation.
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 spillage loss is normal for draft beer?
Between 10-15% is normal for a well-maintained tap installation. More than 20% indicates problems with the installation, pouring technique, or temperature.
Should I factor spillage loss into my selling price?
Yes, otherwise your pour cost won't be accurate. Spillage loss increases your actual cost price per glass, so also your minimum selling price to remain profitable.
How often should I measure spillage loss?
Weekly gives you a good picture. Count the kegs and sales from Monday to Sunday, then you can spot trends and quickly adjust if the percentage increases.
What if my spillage loss goes above 20%?
Check your tap installation: temperature (should be 4-6°C), CO2 pressure, clean lines, and your staff's pouring technique. Often it's one of these factors.
📚 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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