What is the Fast Freeze button on a freezer for?
The fast freeze button bypasses the thermostat to run the compressor continuously, making the freezer much colder than normal. Use it up to 24 hours before adding large amounts of fresh food so the freezer is cold enough to freeze new items quickly without warming what is already stored. Turn it off after 24 hours.
Most freezers include a fast freeze button, but many people never use it or are unsure what it is for. Used correctly, it is a genuinely useful function that helps protect the quality of food being frozen.
What Does the Fast Freeze Button Do?
The fast freeze function is designed for freezing fresh, unfrozen food as quickly as possible. When fresh food is added to a freezer, it raises the internal temperature. This can slightly warm surrounding food that is already frozen, and the new items take longer to freeze solid. Activating fast freeze beforehand lowers the temperature to counteract this effect.
Ideally, fast freeze should be switched on up to 24 hours before adding large quantities of fresh food.
How Does Fast Freeze Work?
The fast freeze button bypasses the thermostat and keeps the compressor running continuously, making the freezer significantly colder than its normal operating temperature. When fresh food is added and raises the internal temperature, the freezer is already cold enough to absorb that rise and freeze the new items quickly without affecting the food already stored.
How to Use Fast Freeze – A General Guide
Instructions vary between models, so always check the appliance manual if possible. See: find instruction manuals for most appliances. The following is a general example based on a typical small freezer:
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Add fresh food to the bottom drawer, which is usually the coldest area. Move existing items if necessary to make room.
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For 5 to 8 kg of fresh food, select fast freeze 24 hours before loading. For 2 to 5 kg, 12 hours is sufficient.
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For under 2 kg, fast freeze can be switched on at the same time as the food is added. Turn it off after 24 hours.
When Else Should Fast Freeze Be Used?
It is also a good idea to switch on fast freeze a few hours before a large shopping trip, even if all items being loaded are already frozen. This helps maintain the correct temperature, reduces the warming effect while the door is open repeatedly, and quickly refreezes any items that begin to soften.
Leaving it on indefinitely is unnecessary and increases energy consumption. Most manufacturers recommend switching it off after 24 hours at most.
Frequently Asked Questions
What happens if I don’t use fast freeze when adding fresh food?
The fresh food will still freeze, but more slowly. During this time the internal temperature rises, which can slightly warm food already frozen in the freezer. For small amounts of food this is unlikely to cause a significant problem, but for larger quantities – such as an unfrozen whole chicken – using fast freeze beforehand is recommended to protect both the new food and existing frozen items.
How long should I leave fast freeze on?
The maximum typically recommended is 24 hours, after which it should be turned off. For smaller amounts of food, it may only be needed for 12 to 24 hours. Leaving fast freeze on permanently is unnecessary and uses more electricity than normal operation.
Does fast freeze use more electricity?
Yes – while fast freeze is active, the compressor runs continuously rather than cycling on and off as normal. This uses more electricity than standard operation. This is why it should only be used when needed and switched off after 24 hours.