Kitchen equipment advice (commercial)

Commercial kitchen equipment maintenance

Regular maintenance and good hygiene practice can help keep your kitchen equipment safe and in good working order.

Fridges 

 

• Follow the manufacturer's instructions
• Do not put it next to a source of heat 
• Use a fridge thermometer and keep food below 8°C
• A packed fridge will not work as well as one which allows air movement
• Keep dry foods at the top
• Keep cooked meats or foods that are ready to eat in the middle
• Keep food that requires cooking, such as raw meat at the bottom
• Do not leave the door open for too long
• Clean the door seals with detergent and disinfectant to remove mould growth

Fridge breakdown

• Throw away spoilt food 
• Clean the inside of the fridge when the power has come back

Freezers

 

• Follow the manufacturer's instructions
• Follow instructions on food packaging
• Keep the temperature of the freezer between minus 18°C and minus 22°C 
• Label food packaging and containers with date of cooked and use-by dates
• A well-stocked freezer is more energy efficient
• Do not allow ice to build up inside freezers
• Defrost freezer units by following manufacturer's instructions

Freezer breakdown

• Keep the doors shut and keep air vents clear
• If raw food still has ice crystals and has not been exposed to any contamination you can refreeze it provided the temperature has not reached above -3°C (if higher cook the food straight away or throw it away)
• Ready to eat food with no ice crystals should be thrown (if ice crystals are present and there has been no risk of contamination, and the temperature is lower than -3°C, then you can eat the food, following the preparation and cooking instructions)
• Clean the inside of the freezer, removing food debris, once the power comes back

If a power failure lasts for more than 8 hours throw away the food.

Microwave cooking

 

Keep your microwave oven clean:

• Cleaning with a detergent and disinfectant will remove dirt and reduce bacteria that have built up - this will ensure that your microwave works efficiently
• Check your microwave manual for recommended cleaning products and methods
• Only use utensils and containers that have been approved for microwave use - poor use may result in damaging the microwave oven, or making the food unsafe

Cook food properly:

• Heat leftovers and pre-cooked food to at least 70°C - food should be very hot and steaming
• Liquids containing meats (like casseroles and stews) must be boiled for roughly five minutes to ensure the pieces of meat are heated through
• Stir things halfway through cooking to avoid cold spots
• Cook food for the minimum time recommended, then test for thorough cooking - juices in chicken, beef, pork and fish should run clear

Ice machines

 

• Connect your machine directly to a mains water supply
• Keep it in an area free from dirt and dust, ideally off the ground and in a position which provides ventilation and easy access
• Service the machine following the manufacturer's instructions
• Remove dust, grime and limescale regularly
• Clean all ice handling equipment, such as buckets and tongs or spoons, regularly throughout the day
• Do not allow ice to be transferred by hand - train staff in proper handling procedures
• Do not store bottles, cans or glasses in the ice intended for human consumption
• Ensure scoop handles are not in contact with ice

Vacuum-packing machines

 

• Follow the manufacturer’s guidance and service it regularly
• Change the oil as necessary
• Regularly check seals and replace them if they are damaged to prevent a poor vacuum
• Do not dual-use machines. If you use a vacuum packer for raw meat you can't use it next for ready-to-eat foods
• If you buy a second hand machine, check its history. If it was used for raw foods and you want to use for ready-to-eat foods, you will need to dismantle it for cleaning and disinfection

Packaging specifications for bags

 

• Make sure they are puncture proof
• Make sure they meet your temperature specification such as for sous-vide cooking
• Check that they are heat sealable
• Ensure they are suitable for food use

Shelf life of vacuum packed foods

 

• The spores of Clostridium and Bacillus species are heat resistant and grow in the absence of oxygen
• To prevent bacteria growth follow a maximum shelf life of 10 days for vacuum-packed products stored at 3-8°C
• A chilled shelf life of 10 days or more is permitted if one or more of the following are met:
  • pH of 5 or less throughout the product
  • Aw of 0.97 or less throughout the product
  • Heat treatment of 90°C for 10 minutes or equivalent throughout the product
  • Salt of 3.5% (aq) or greater throughout the product
  • Any combination of factors proven to inhibit growth or toxin production by C. botulinum

Read more about vacuum packed foods.

The Food Standards Agency offers information on vacuum packing.

Sous-vide waterbath

 

Cleaning:

• Use potable water as heat transfer media
• Discard water and clean waterbath after every use
• If possible, put equipment through a hot dishwasher cycle 

Cooking:

• Sous-vide or “under vacuum” processes commonly feature cooking at lower temperatures over extended periods than often found in commercial settings.
• If the process is defined as critical to food safety, then a suitable time/temperature combination must be achieved

The table below shows exerts of time/temperature controls for Listeria monocytogenes.

Temperature at the slowest heating point (°C)	Time (minimum)
60	43.48
65	9.30
70	2.00
75	26 seconds
80	26 seconds

The table below shows E.coli 0157 time/temperature controls.

Temperature (°C)	Time (minimum)
60	93 minutes
65	13.6 minutes
70	2 minutes
75	18 seconds
80	3 seconds

Calculating cooking time:

Time to waterbath equilibration + Time to thermal centre of product achieving cooking temperature + Desired cooking time = Total time a product should be placed in the waterbath

This could be done once for each recipe mimicking a “worst case scenario” and then checked using a calibrated temperature probe each time the product is prepared. 

When to do temperature measurements:

• At the start of the sous-vide to check water temperature
• At the start of cooking time to make sure thermal centre (the middle of the thickest part) of the product is at desired temperature
• During process to check water temperature
• Check thermal centre at end of process to confirm temperature has been maintained

All process temperatures should be measured at the thermal centre of the product. The coolest part of a product during cooking, usually the middle of the thickest part of the product. 

 Take into account:

• The time it takes for the water in the bath to reach the desired temperature after putting the product in the water
• How long it takes for the product to reach correct temperature at the core
• When checking the product temperature, you will need to use expanding foam tape and a needle nose thermometer to ensure bag integrity is maintained

Calibration:

• All instrumentation should be of sufficient accuracy and precision – minimum of ± 1°C, preferably ± 0.5°C
• Calibration frequency for working thermometers should be at least annually.
• Valid calibration certificates should be kept on file for all instrumentation used in the validation of heat-chill processes
• Boiling water vs. Iced water “Calibration” is not sufficient to accurately calibrate a needle nose probe thermometer.