How often should you clean beer lines?

Last updated: 26 June 2026

Most pubs clean their beer lines monthly. Most pubs also leak money they never see. The two facts are not unrelated. The most effective beer line cleaning schedule is weekly—not monthly—because draught losses compound silently and are invisible until you dip the cask. You don’t feel a bad line the way you feel a bad till. But a poorly maintained line costs you just as much: bad temperature control, bacterial growth, inconsistent pours, and flat beer all hide inside poor cellar hygiene. If you’re wondering whether weekly line checks are really necessary, the answer is yes—and I’ll show you exactly why, and what you’re actually looking for when you check.

Weekly Checks Are Non-Negotiable

Here’s what I learned the hard way: a brewery stocktaker visits your pub once a month, maybe once every six weeks. In that time, a dirty line can be quietly ruining your product and your GP. You won’t know it until the take is in the till doesn’t match the dip. By then, the damage is done—and you’ve no idea when it started.

Weekly line checks are your early warning system. You’re not necessarily deep-cleaning the lines every week—that’s a job for a professional line cleaning service, which you should contract quarterly or when problems arise. What you are doing weekly is this: checking temperature, checking for foaming or cloudiness, listening for unusual sounds in the pump, and testing the pour quality. These five minutes per line catch 90% of cellar disasters before they cost you money.

A 1% stock loss on wet sales quietly costs a typical pub £3,000–£5,000 a year. Most of that loss isn’t theft—it’s measurement error, forgotten wastage, and line waste that nobody logged. A proper weekly line check doesn’t catch all of it, but it catches the part you can actually do something about: the draught beer that’s going flat, warm, or sour before it reaches a customer.

What You’re Actually Checking

When I say “line check,” I don’t mean a full clean. I mean a structured 5-minute inspection of each draught line. Here’s exactly what to look for:

• Temperature: Your cellar should be 50–52°F (10–11°C). Anything above 55°F accelerates bacterial growth and CO2 loss. Check your cellar thermometer, not guesswork.
• Pour quality: Pull a pint. Does it foam excessively? Is it flat? Does it taste right? If it tastes off or pours strange, the line is dirty or the pressure is wrong.
• Visual inspection: Look inside the tap. Is there visible slime or discoloration inside the nozzle? That’s bacteria.
• Keg pressure: Check the regulator. Is it holding steady, or creeping up? Creeping pressure means a blockage in the line.
• Pump sound: A pump that sounds strained or irregular may have a problem you can’t see yet.

That’s it. Not complex. Not time-consuming. Just consistent. The difference between a pub that leaks 1% on draught and a pub that loses 0.3% is usually just this: one person dips the cask and checks the line every Thursday, and the other person doesn’t.

When you use StockTap pub stock app, you can log these weekly observations in the same place you track your cask dips and empty kegs. You see the pattern over time. If a line is consistently hot or foaming on Fridays, you know it’s a temperature or CO2 problem, not a one-off anomaly.

The Temperature Trap

This is the insight that only someone who actually runs a cellar understands: most pubs don’t have a temperature problem in the cellar. They have a temperature problem on the line.

Your main cellar might be 51°F. Perfect. But the beer travelling through 40 feet of line behind the bar, especially if that line runs near a radiator or in a warm cupboard, can warm up to 57–60°F by the time it reaches the tap. That warm beer tastes flat, foams heavily, and spoils quickly. The bacteria in a warm line double every 20 minutes. By the time you’re six hours into service, you’re serving sour beer without realising it.

Line temperature is harder to control than cellar temperature, and it’s the reason weekly checks matter more than many pub operators think. You can’t measure the beer temperature inside the line without a probe (and most pubs don’t have one). What you can do is pull a test pint and taste it. If it tastes warm, flat, or off, the line is the problem.

The solution is either to run cooler beer through the system (reduce cellar temperature slightly), insulate the line better, or move it away from heat sources. A professional line cleaning contractor can advise you when they visit. But if you’re checking weekly, you’ll spot the issue within two weeks of it starting, not three months later.

How to Log Your Checks

Here’s where most pubs fail: they do the check, but they don’t write it down. A week later, they can’t remember if the Guinness line was foaming last Thursday or the Thursday before. Without a record, you’re flying blind.

I used to run stock on a tangle of spreadsheets and still lost track of partial kegs and line issues. When I built a simple count routine around a dipstick, a set of scales, and a weekly log, the variance went from guesswork to a number I could trust within a fortnight. The same applies to line checks: the log is more valuable than the check itself.

What you need to record:

• Line name (e.g., “Guinness 1”, “IPA Tap 2”)
• Check date and time
• Cellar temperature (from your thermometer)
• Pour quality (normal, foaming, flat, off-taste)
• Any action taken (pressure adjustment, line clean scheduled, keg swapped)
• Next review date

A spreadsheet works. Paper works. But when you move your entire stock routine into one place—dips, scales, line checks, temperature logs, and daily variance—you start to see the real picture. That’s why SmartPubTools was built around the cellar, not just the till. The number that actually matters is wet GP by line, not a single headline stock figure. Spirits hide losses in over-pouring. Draught hides it in poor cellar temperature and bad line cleaning waste. When you log the line temperature and the dip on the same day and check the variance against the till, you know exactly where the leak is.

Common Excuses (And Why They Cost You)

I’ve heard all of them. Let me address the ones that actually matter:

‘I don’t have time for a weekly line check.’

A line check takes five minutes per line. Even a 12-tap bar takes an hour once a week. You lose more than that every time a keg runs flat during service. You also lose far more in margin on spoiled beer. Find the time.

‘My spreadsheet works fine.’

Your spreadsheet tells you what you think should be there. It doesn’t tell you what’s actually in the cellar. A dip and a weekly line log tell you the truth. Most pubs that move from a messy spreadsheet to a disciplined count claw back 1–2 GP points within a couple of months. That’s not from finding theft. It’s from finding waste and plugging the leak.

‘Won’t the brewery stocktaker just do it?’

No. The brewery stocktaker counts the kegs and checks the invoice. They don’t taste your beer or measure your line temperature. Their job is the brewery’s margins, not yours. Your job is yours. Do your own checks.

‘Do I really need special equipment?’

No. You need a thermometer (£5), a glass, and a notebook. That’s your entire cellar audit toolkit. Everything else is nice-to-have. The discipline matters more than the gadgets.

Making the Weekly Habit Stick

The hardest part isn’t the checking. It’s the routine. Most pubs do a line check once, feel virtuous, and then forget about it for three weeks. Here’s how to make it stick:

• Pick a day and time: Every Thursday at 2 PM. Same day, same time. Build it into your opening checklist or your afternoon routine. Habits only form through repetition.
• Assign one person: If it’s “someone’s job,” it’s nobody’s job. Make it one person’s responsibility. Rotate it quarterly so everyone learns the skill.
• Log it immediately: Check the line, log the result in the same five minutes. Don’t save it for later. Later never comes.
• Review the log monthly: Every month, spend 10 minutes looking at the past four weeks of line checks. Do you see a pattern? Is one line consistently warm? Is one tap foaming every Friday? That’s information worth acting on.
• Schedule professional cleaning quarterly: Every 12 weeks, call in a line cleaning company. They’ll deep-clean your lines and spot problems you can’t see. It costs £150–£300 and saves you thousands in lost margin and spoiled stock.

That’s the complete system. Weekly dips + weekly line checks + monthly review + quarterly professional clean. It takes two hours a month. It saves you £3,000–£5,000 a year, minimum.