The short answer is twice a day: once in the morning before service, once in the evening at close. That applies to every fridge, every freezer, and every hot-hold unit in the kitchen.
The slightly longer answer is the one that matters, because the difference between a kitchen that does this properly and a kitchen that does not is rarely the temperature. It is almost always the timestamp.
Where the rule comes from
There is no specific UK statute that says “thou shalt check thy fridge twice a day”. What the law (Regulation (EC) 852/2004, retained as assimilated UK law) actually requires is that you operate a system based on HACCP principles, monitor your critical control points, and keep records that demonstrate you are doing it.
In practice, the FSA's Safer Food Better Business (SFBB) pack (and CookSafe in Scotland) translates that legal requirement into a working norm: two readings per day per unit, AM and PM. Every Environmental Health Officer (EHO) you ever meet will use that as the baseline. A kitchen logging once a day gets a question. A kitchen logging once a week gets a finding.
So the answer to “how often” is twice a day not because the law specifies it, but because it is the standard the inspectors apply, and it is the minimum frequency that catches the kind of failure a fridge actually has.
Why one reading a day is not enough
A fridge can fail in any number of ways: a compressor that quietly stops overnight, a door that gets left ajar at the end of service, a thermostat that drifts, a defrost cycle that does not complete. A single reading at 8 AM will not catch any of these.
The PM check is the one that matters. It is the reading that tells you whether the unit was holding temperature through the busiest part of your day, when the door was opening every minute. It is also the reading that, if missed, lets a failing unit run unmonitored for the next 12 hours, which is plenty of time to spoil a freezer's worth of stock or, worse, to grow pathogens in stock that gets used the next day.
Twice a day exists because once a day genuinely does not catch service failures, and three times a day is a level of friction most kitchens cannot sustain.
The noon boundary, AM and PM
In a Lemon log (and in most digital systems built around UK food safety), the day is split at noon. Anything before is the AM reading; anything after is the PM. If you take a reading at 11:45 it counts as AM, even if you are an hour late. If you take it at 12:15 it counts as PM, even if it was meant to be the morning check.
This sounds petty, but it matters because the inspector's question is “did you check this fridge during morning service and during evening service?” not “did you check it twice in 24 hours?”. A reading at 11 PM and another at 1 AM is technically two readings, but it is two PM readings, and it tells the inspector nothing about the morning.
Who should be doing it
The reading itself takes 10 seconds. The systems question is who is accountable.
The kitchens that do this well treat fridge readings as a closing-team responsibility, the same way wiping down the line is. Specifically:
- AM reading: the chef opening the kitchen. First job, before mise.
- PM reading: the chef or KP closing the kitchen. Last job, before the lights go off.
The mistake to avoid is making it the head chef's job. The head chef is not always there, and the moment they are not, the readings stop. Make it positional, not personal.
Each entry should be attributable to the person who took it, by name. That is not a Lemon thing, that is an EHO thing. “Who took this reading?” is one of the standard questions, and a log without names is a log that does not pass.
What the timestamp is actually for
Here is the part most kitchens miss. The temperature on the page is not the most important piece of information. The time the reading was taken is.
A page of perfect 4 °C readings, all written in the same biro, all dated this week but clearly written this morning, is worse than no records at all. The inspector can spot it at a glance, and it actively harms your confidence-in-management score. It signals two things at once: (1) the readings probably were not taken when they are dated, and (2) somebody in this kitchen thinks the inspector will not notice.
What the inspector actually wants is a record that proves the reading was taken at the moment the timestamp says it was. There are three ways to provide that:
- A digital system that timestamps automatically at entry. This is what a phone-based app does. The reading goes in at 7:42 AM, and 7:42 AM is what is recorded. You cannot backdate it, you cannot edit it later, and the inspector knows that.
- A paper diary filled in at the time, in front of a witness. Workable in theory, hard in practice, and easy for an inspector to question.
- A wall-mounted thermometer with a printout function. Reliable for the temperature, but the printout does not tell anyone whether a human looked at it.
Most paper diaries fall into a fourth category, which is “filled in retrospectively”. That is the one that ends inspections badly.
What happens if you miss one
You will miss one. Everybody does, eventually. The PM check is the most-missed reading in any kitchen, and the right response when you realise you missed it is not to make one up.
The right response is:
- Mark it as missed, dated honestly.
- Take the next available reading as soon as you can.
- If anything is out of range, follow your corrective action procedure (move stock, throw at-risk product, call the engineer).
- Note in your records what you did about it.
A missed reading with an honest note is a small mark against you. A missed reading filled in dishonestly the next day is a big mark, if it gets caught, and a serious problem if you ever need to defend a due-diligence claim under the Food Safety Act 1990 (the records that make that defence stick are covered in our piece on UK fridge temperature law).
A working routine for a busy kitchen
Twice a day, every cold unit, every hot hold. Specifically:
- AM, on opening: every fridge, every freezer, hot hold (if it is running through breakfast). Probe reading, not just the door display, where the unit allows.
- PM, at close: the same units, including the hot hold being switched off. Confirm everything is back in range.
- During service, on a busy day: spot checks on the unit you have been opening most. A prep fridge that has been opened 200 times during lunch is the one to keep an eye on.
That is it. About 90 seconds of work twice a day per unit, with a clean record at the end of it.
How to make it stick
The honest answer is that this is one of those things that is easy in theory and quietly impossible in practice with paper. The diary lives in the office, the chef is in the walk-in, and the closing team is exhausted. Three weeks in, the PM checks start sliding.
A phone-based system fixes most of this because the diary is in your pocket. Lemon is the one we make: AM and PM readings for every unit, automatic timestamps, named entries, out-of-range values that open a tracked corrective action, and a one-tap PDF export when the inspector asks. Around 900 UK kitchens use it, and they have recorded over 400,000 food safety checks between them. Trial is 30 days, no card.
