What temperature should a beer cellar be?

Why cellar temperature matters

Cask ale is still conditioning in the barrel. Too warm and it works too quickly, pours lively and fobby, and goes off sooner, so more is lost down the drip tray and each cask yields fewer saleable pints. Too cold and conditioning stalls, the beer can turn hazy and flavour is muted. Keg products are more forgiving, but a warm cellar still makes the remote coolers work harder and can lead to foaming at the tap.

In short, cellar temperature affects quality, customer complaints and profit on every barrel.

What pushes a cellar off temperature

• Deliveries: warm casks and kegs arriving on a summer afternoon add heat all at once.
• Hatches and doors left open, or with worn seals, letting outside air flood in.
• Heat from equipment: python coolers, ice machines or bottle coolers sharing the space.
• Poor insulation on walls, ceilings or hatches, especially in older buildings.
• A cellar cooler condenser that is dusty or boxed into a tight, unventilated spot outside.

Keeping it steady day to day

• Hang a thermometer at barrel height, away from the cooler outlet, and read it at the same times each day.
• Keep the cooler's airflow clear. Do not stack empties or boxes in front of the evaporator.
• Close the hatch and door as soon as a delivery is in.
• Give new casks time to settle before tapping so they reach cellar temperature.
• Keep the outdoor condenser clear of leaves, bins and rubbish.

Signs the cellar cooler needs an engineer

If the cellar creeps upward during warm weather and never recovers overnight, the cooler is struggling. Other warning signs include ice forming on the evaporator inside the cellar, the unit running constantly, water pooling beneath it, or the outdoor unit making new noises. Many of these come down to a fouled condenser or poor ventilation, which cleaning and correcting airflow can often fix. Others, such as refrigerant leaks, need an F-Gas certified engineer.

Our separate guide on a cellar that is running too warm goes into fault finding in more depth.

Servicing and support

Ted McCarthy Services installs, repairs and services cellar cooling for pubs, bars and restaurants from a Hemel Hempstead base across Hertfordshire, Buckinghamshire, Bedfordshire and London. When a cooler is past saving, a replacement is sized against the cellar volume, insulation, door and hatch losses, and the heat from incoming stock.

Many pubs put cellar cooling, ice machines, bottle coolers and bar air conditioning on a single refrigeration maintenance contract, with planned visits, F-Gas leak checks where required, a written report after each visit, priority response and access to the out of hours line. To talk it through, call 07940 953486, Monday to Friday, 08:00 to 17:00.