How to Stocktake Draught Beer Properly

Last updated: 26 June 2026

Most pubs lose money on draught beer every single week and never know it. Not because of theft—because of how they count it. A 1% stock loss on wet sales quietly costs a typical pub £3,000–£5,000 a year, and the majority of that loss is hidden in poor cellar temperature, bad line cleaning waste, and measurement error rather than actual shrinkage. If you’re running your draught stocktake on guesswork, a tape measure, or memory, you’re almost certainly leaving money on the table. This guide walks you through how to stocktake draught beer the way it actually works in a busy pub—with equipment you probably already have, a count routine you can do in 20 minutes, and variance numbers you can trust by the end of week one.

Why Draught Stocktake Matters

I spent five years running my stock on a tangle of spreadsheets. I’d count kegs on a Tuesday, write down what I thought was left, and hope the number matched my till at month-end. It never did. The gap was anywhere from 2% to 4%, and I genuinely didn’t know whether it was waste, over-pouring, bad line cleaning, or actual loss. Then I built a simple count routine around a dipstick and a set of scales, and the weekly variance went from guesswork to a number I could trust within a fortnight.

The reason draught beer stocktakes matter so much is that the number that actually matters is wet gross profit by line, not a single headline stock figure. You need to know whether your best cask is making money or bleeding it dry. A spreadsheet tells you what you sold. Draught stocktake data tells you whether you made money on what you sold.

If your cellar temperature sits at 14°C instead of 12°C for a week, you’re losing 1–2% of every cask to excess foam and oxidation. If your Guinness line runs 8 metres with no carbonation check and hasn’t been cleaned in a fortnight, you’re pouring 30% headspace. If you’re not reconciling your count against your till the same day, you can’t spot which line is the problem. All three of these are invisible on a monthly P&L—but a weekly line check catches them instantly.

Equipment You Need

You don’t need fancy kit. You need three things: a calibrated dipstick, a set of scales that reads in 0.1kg increments, and a pen. That’s it.

Calibrated Dipstick

A calibrated dipstick is a marked wooden rod or plastic stick that tells you the depth of liquid in a cask. The calibration matters—it must account for the specific cask size (11-gallon UK kegs are standard for ales; draught Guinness runs 11-gallon or 30-litre containers). A standard dipstick from a brewery rep will have depth markings in litres or gallons. Buy one from your main brewery account (Marston’s, Greene King, Guinness, whoever supplies your main lines) and ask for a fresh one every year—old sticks warp.

Don’t use a tape measure or eyeball estimate. Eyeballing a cask gives you a variance of ±3–5% per count. A dipstick gives you ±0.5% if you use it the same way every time.

Scales

Buy a set of digital kitchen scales that read in 0.1kg increments—around £20–30. You’ll use these to weigh any open cask or partial keg, because you can’t dipstick a container that’s less than a quarter full. A 20-litre Carlsberg keg weighs roughly 28kg empty; if it weighs 35kg, you’ve got about 7 litres left. Record the gross weight, not the estimated content.

Thermometer and Logbook

A simple max/min thermometer in your cellar (£10–15) and a one-page weekly log sheet. Record cellar temperature at the same time every week. If your temperature varies more than 2°C across the week, you’re losing volume to temperature fluctuation. Your logbook becomes your variance audit trail.

The Weekly Count Routine

The most accurate draught beer stocktake happens once a week, takes 20 minutes, and reconciles against till data the same day. Here’s how to run it.

Step 1: Pick a Fixed Day and Time

Every Tuesday morning at 10am. Every Thursday after closing. Same day, same time. Variance becomes meaningful only if you count the same way, at the same frequency, with the same gap between counts. Weekly is the minimum—anything longer and you’re trying to solve a three-week-old problem.

Step 2: List Your Active Lines

Write down every active draught line: Guinness, bitter, lager, cider, prosecco, whatever. Include the current cask size and the date the cask went on. Most pubs run 6–12 lines; if you’re running more than 12, you can’t stocktake properly because the cellar is overcrowded and you can’t manage temperature or cleaning.

Step 3: Dip or Weigh Each Cask

For full and three-quarter casks: use the dipstick. Insert it vertically to the bottom, mark where the liquid level reaches, read the marking. Write down the exact depth in litres or gallons—be consistent with units week to week.

For half-full or less: use the scales. Place the cask or keg on the scales, record the gross weight, subtract the empty cask weight (ask your brewery for the empty weight spec), and calculate remaining volume. This is more accurate than trying to dipstick a half-empty container.

Step 4: Record Cellar Temperature

Check your max/min thermometer. Write down the high and low for the week. If the low drops below 11°C or the high climbs above 14°C, note what happened (door left open, cooler malfunction, warm spell) and flag it in your variance log for that week.

Step 5: Reconcile Against Till Data the Same Day

Pull your till reading for that week (litres or pints sold by line, if your EPOS can split it). For each line, calculate expected remaining stock: last week’s closing stock plus deliveries minus till sales. Compare that to this week’s physical count. Any gap is your variance.

Example: Guinness last week ended at 8 litres. You took delivery of one 11-gallon cask (50 litres) on Monday. Your till shows 42 litres sold. Expected remaining: 8 + 50 − 42 = 16 litres. You dipped 15 litres today. Variance: −1 litre. That’s acceptable (2% loss on a 50-litre cask due to line purge, pouring trim and temperature). If you’d dipped 12 litres, variance is −4 litres (8%)—something is wrong: temperature, line cleaning, or over-pouring.

Reading Cask Depth Accurately

Cask depth reading must be done the same way every time to be reliable; insert the dipstick to the bottom, wait three seconds for foam to settle, and read at eye level.

Most operators insert the stick, glance at it from above while holding it at an angle, and read the wrong depth marker. That’s why your variance swings by 2–3 litres week to week.

Here’s how to read it accurately:

• Insert the stick vertically until it touches the cask bottom. You’ll feel it bump.
• Hold it steady for three seconds while foam settles around the stick.
• Bring your eye level with the liquid surface on the stick—don’t read from above or below.
• Read the nearest 0.5-litre marking (or 1-gallon marking if your stick is in gallons).
• Write it down immediately. Don’t guess or round.

If you’re reading the same cask today and it says 32 litres, and yesterday you read 35 litres, you either read it wrong yesterday or the cask has been used overnight. Check the till. If till shows 4 litres sold, you read it wrong yesterday. If till shows no sales, something else happened—the cask was leaking, or it was tapped overnight without till entry.

Variance Reconciliation Against Till Data

This is where most pubs fail. They count stock, get a number, file the spreadsheet, and never reconcile against what the till says sold. That’s why they don’t know whether they have a theft problem, a temperature problem, or a line-cleaning problem.

Reconciliation is simple: expected stock (opening + deliveries − till sales) versus actual stock (physical count). The gap is variance.

A variance of 0–2% per cask per week is acceptable and covers standard line purge, pouring trim, and spillage.

A variance of 2–4% per cask per week means something is off: temperature is too high, line is clogged with yeast, or you’re over-pouring by habit.

A variance of 4%+ per cask per week means a real problem: line leak, bad temperature control, or actual loss.

Track variance by line on a spreadsheet or, more reliably, using the StockTap pub stock app, which logs cask depth, till data, and variance automatically and flags lines that drift above 2% week on week. Most pubs that move from a messy spreadsheet to a disciplined count claw back 1–2 gross profit points within a couple of months through waste reduction alone—not because they stopped theft, but because they stopped ignoring the temperature dial and the line cleaning schedule.

Common Mistakes That Kill Accuracy

Mistake 1: Not Counting at the Same Time Every Week

If you count on Tuesday one week and Friday the next, your cask usage is spread across different spans of time and variance becomes meaningless. Fix a day and a time. Stick to it.

Mistake 2: Estimating Open Casks Instead of Weighing Them

An open cask with 8 litres left looks like 5 litres or 10 litres depending on the angle and the foam. Weigh it. It takes 30 seconds. Your variance will thank you.

Mistake 3: Not Recording Deliveries in Real Time

A keg comes in on Wednesday. You assume it arrived Tuesday and count it wrong. Log deliveries in your stocktake sheet the moment they arrive—cask size, product, date in, date on, date off. Your variance reconciliation depends on knowing exactly what came in and when.

Mistake 4: Relying on the Brewery Stocktaker

The brewery sends a rep once a month. They might tell you “you’ve got three-and-a-half Guinness kegs.” That’s a guess. They’re trying to work out your reorder. They’re not auditing your cellar. You are responsible for your variance. Do your own count weekly.

Mistake 5: Ignoring Partial Kegs and Open Casks

Most variance hides in partial kegs and open casks because they’re hard to count and easy to forget. They must be weighed or dipped every single count cycle, not estimated or skipped. A half-empty 20-litre lager keg that you skip in week three will be three-quarters empty by week four, and you won’t have a clue where the stock went.

Mistake 6: Not Checking Cellar Temperature

Temperature fluctuation is one of the biggest silent stock loss vectors in pubs. A cask kept at 15°C generates excess foam and oxidation. A cask at 10°C pours flat and takes longer to sell. Log the temperature every week. If it’s drifting, fix the cooler or call your brewery.

Should You Use a Spreadsheet or an App?

A spreadsheet works if you’re disciplined. But most operators aren’t—they skip weeks, forget to log deliveries, and end up with data gaps that make variance meaningless. An app like SmartPubTools removes the guesswork by prompting you for cask depth, till data, and temperature in sequence and calculating variance automatically. You can’t accidentally skip a field or forget to reconcile. But an app is only as good as the data you feed into it.

The minimum requirement is a one-page weekly log that includes: date, cask name, cask size, previous depth, today’s depth, deliveries that week, till sales, expected variance, actual variance, cellar temperature, and notes. If you’re using a spreadsheet, build that template and use it every single week without fail. If you’re using an app, make sure it has those fields and that you fill them in at the same time every week.