Keep Your Cellar at the Right Temperature

Last updated: 2 May 2026

Most pub landlords check their cellar temperature once a week and hope for the best. What they don’t see is the slow damage happening every single day — flat beer, broken cask seals, yeast stress, and stock loss that eats straight into your margin. The right cellar temperature is not optional: it’s the difference between serving a proper pint and handing customers liquid regret. This guide shows you exactly what temperature your cellar should be, why it matters more than you think, and how to stop temperature swings from destroying your profit.

What Temperature Should Your Cellar Be?

The target cellar temperature for cask ales and lagers in UK pubs is 12–14°C, with 13°C as the ideal set point. This is not a pub operator’s preference—it is the standard laid down by the Brewers Association and followed by every brewery in the country. If your cellar is at 16°C, you are too warm. If it drops below 11°C, you risk harming yeast stability and serving customers flat, sour, or off-flavour beer.

I learned this the hard way in my first year at Teal Farm Pub. A faulty cellar cooler let the temperature drift to 17°C for three days without me noticing. The result: three damaged casks I had to send back to Marston’s, lost pints, an upset customer base, and a frank conversation with my BDM about why I’d let quality slip. That one mistake cost me more than a replacement thermometer would have cost me in ten years.

Different beer styles have slightly different ranges. Most cask ales work best at 13°C. Some lagers prefer 12–13°C. Craft keg beers can sit at 13–15°C depending on the brewery. But in a typical tied pub under a pubco agreement, you are serving what they tell you to serve, and their standard is 12–14°C. Stick to that range and you will not go wrong.

Why Cellar Temperature Matters for Your Beer

Temperature controls five critical things in your cellar: yeast activity, gas pressure, cask seal integrity, flavour stability, and shelf life. Get it wrong and every single one of those suffers.

Yeast Activity and Carbonation

Yeast is not dead in a cask. It is dormant and slow-moving, which is how you keep the beer stable. When temperature rises above 15°C, yeast wakes up. It starts eating again, producing more gas and acid, which pushes the cask seal off and creates flat, vinegary beer. I have seen a cask go from perfect condition to completely flat in five days under a warm cellar. Customers notice. Your takings notice. Your reputation notices.

Gas Pressure and Dispense Quality

Cask ales need the right internal pressure to dispense properly. Temperature changes alter that pressure directly. Too warm, and the pressure builds too fast, causing foaming and waste at the pump. Too cold, and the pressure drops, making the beer hard to pull and leaving you short-pouring by accident. Either way, you are losing money—through waste or through shortfall.

Cask Seal Failure

Elevated cellar temperatures are the single most common cause of cask seal failure in UK pubs, and seal failure is the fastest route to stock loss and customer complaints. The rubber and plastic seals on cask taps are designed to function within a narrow temperature band. Push the temperature up to 16–18°C, and those seals start to degrade. Pressure builds, seals give way, and beer leaks from the cask into your cellar floor. I have seen a pub lose a full cask of ale (36 pints) in a single shift because the cellar temperature drifted 3 degrees too high.

Flavour Stability

Even if the beer does not go visibly flat, higher temperatures age beer faster. The flavour profile shifts, hops deteriorate, and the beer tastes tired. Customers might not know why a particular pint tastes off, but they will not order it again. On a pub with 30+ cask ales on rotation, losing repeat orders on two or three lines because of temperature stress adds up quickly.

How to Monitor and Control Cellar Temperature

The Thermometer: Non-Negotiable

You need a thermometer in your cellar. Not a guess. Not a “it feels cold enough”. A thermometer. Ideally, a digital one. A basic digital thermometer costs £12–25. Stick it in the main part of the cellar, away from the cooler unit and away from direct air intake, so you get a reading of the actual cellar air temperature, not a false reading from the cooler itself.

Check it every morning when you open. Record it. It takes 30 seconds. If you see drift—anything above 14°C or below 11°C—investigate and fix it the same day. Do not wait for stock to go bad.

The Cooler: Maintenance Matters

Most tied pubs inherit a cellar cooler from the pubco. It probably works. It might also be five years old, clogged with dust, and running at 80% efficiency because nobody has cleaned the condenser coils since the previous landlord left. A cellar cooler with a blocked condenser will struggle to hold temperature, especially on a warm day or if you have had a busy service.

Clean the cooler condenser coils every three months. Vacuum the intake grille. Check that the thermostat is actually set to 13°C and not left on some random setting. If the cooler is more than seven years old and you are chasing temperature every week, talk to your pubco about replacement. Most will help with the cost.

Insulation and Airflow

A badly insulated cellar or one with warm air leaking in will fight your cooler constantly. Close doors quickly. Do not leave cellar doors propped open during service. If your cellar is under a kitchen or above a warm room, that heat transfer will push your temperature up. There is not much you can do about the building structure, but you can be conscious of it and manage accordingly.

Seasonal Adjustment

In summer, cellar temperatures naturally want to drift higher. In winter, they drop. Some pubs in unheated cellars can dip to 10°C in January. Check your cooler thermostat is actually working and adjust seasonally. Modern coolers have a small dial or digital display. If yours does not, ask your pubco if they can upgrade it.

Common Temperature Problems and How to Fix Them

The Cellar is Too Warm (Above 15°C)

Check these in order:

• Is the cooler actually running? Listen for the compressor. Feel for cold air from the intake. If it is silent, it is off.
• Is the thermostat set correctly? It should be set to 13°C. If it is at 18°C or on manual, no wonder the cellar is warm.
• Are the condenser coils blocked? Dust and debris will choke the cooler. Vacuum them.
• Is the cellar door sealed properly? A gap at the bottom will let warm air pour in from the pub floor.
• Is the cooler sized for your cellar? A small cooler in a large cellar will struggle, especially in summer. Your pubco can advise.

If it is summer and you are 0.5–1°C above target, do not panic. You can live with 14.5°C for a week if you have to. If you are above 16°C, treat it as urgent. Phone your pubco and request support. They will send an engineer, usually within 48 hours. Do not let it slide.

The Cellar is Too Cold (Below 11°C)

This is less common in occupied pubs, but it happens in winter or in cellars that are poorly heated. Cold cellar temperatures slow yeast, flatten cask ales, and can eventually cause cask seals to contract and crack. If your cellar is consistently below 11°C:

• Check that the cooler thermostat is not set lower than it should be.
• If the building is genuinely cold, speak to your pubco about insulation or a heated cooler unit.
• In the short term, you can slightly reduce cooler run time, but this is a band-aid.

Extreme cold is less of a stock-loss problem than extreme heat, but it still makes your beer taste worse. Try to keep it above 12°C.

Temperature Logs and EHO Compliance

During an Environmental Health Officer inspection, one of the first things they will ask to see is your temperature records. Not as a courtesy. As evidence that you are actively managing food safety in your cellar. Beer and cider are regulated as food products under the Food Safety Act, and temperature control is part of your due diligence.

You do not need an expensive system. A simple daily log with the date, time, temperature, and your initials is sufficient. Many pubs use a printed template. Some keep a notebook. Some use a digital system like Pub Command Centre, which includes a cellar temperature screen so all your records are time-stamped and audit-ready.

I keep a printed cellar temperature log on the cellar wall. Every morning, I record the reading. Every week, I review the log for drift. When my EHO visited in March 2026, she asked to see the log, flipped through it, nodded, and moved on. No issues. That is what a compliant approach looks like.

If you take the pub over from another licensee, do not assume the previous owner kept records. They probably did not. Start fresh. Your records are your proof that you are in control. An EHO inspecting your pub and finding no temperature records will assume you are not managing the cellar, whether or not that is true. The absence of evidence is treated as evidence of absence.

Investing in the Right Equipment

Do not overthink this. A basic digital thermometer is enough to start. If you want to step up slightly, consider a min-max thermometer, which shows you the highest and lowest temperatures your cellar reached since the last reset. That tells you whether the cooler is swinging wildly or holding stable. They cost £20–40.

If you want to go further—and I would recommend it for any pub serious about consistency—look at a wireless temperature monitor. These sit in your cellar and send readings to your phone. You can set alerts, so if the temperature drifts above 15°C or below 11°C, you get a notification immediately. Brands like Lascar and Testo make reliable units. Expect to pay £80–150 for a decent one. That is still cheaper than one spoiled cask of ale.

Never buy an expensive cooler system without checking with your pubco first. Most tied pubs are tied into specific equipment, and your agreement might prevent you from changing the cooler without permission. Ask first. It takes five minutes and avoids a costly mistake.

When planning your setup, use a pub profit margin calculator to understand how stock loss impacts your gross profit. A single wasted cask (36 pints at £3.50 each) is £126 lost revenue. One temperature incident per month costs you over £1,500 per year. A £100 thermometer pays for itself in the first three weeks.

Getting cellar temperature right is not glamorous. It does not feature in pub marketing or customer-facing operations. But it is one of the few things you directly control that impacts both quality and cost of goods sold. A badly managed cellar costs you thousands in wasted stock every year. A well-managed one protects your margin, improves your product, and keeps your EHO satisfied.

The real insight most pub operators miss is this: temperature control is not a once-a-week task. It is a daily habit. Spend 30 seconds every morning checking and recording. Spend five minutes every week reviewing the log for drift. Spend two hours every three months cleaning the cooler. That is it. That is the full investment, and it will save you more than you will ever spend.

Before you take on a tied pub or move to a new location, make cellar condition and cooler age part of your due diligence. Ask the pubco when the cooler was last serviced. Ask to see the previous landlord’s temperature records. If the building has a warm cellar or a failing cooler, negotiate that repair into your tenancy agreement upfront. Do not inherit someone else’s temperature problem.

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