Refrigeration used to preserve foods dates back to prehistoric times. At the time, people used snow and ice to store hunting products. Slow freezing was risky; it was not until the 20th century that the commercialization of frozen foods began with the discovery of a rapid freezing method: the deep freezing.
In order to reach a negative core temperature for preservation, there are 2 options: freezing or deep freezing.
Do you know the differences between freezing and deep-freezing? How do these two techniques work and affect food?
Reaching a negative core temperature to preserve food is an essential element of any food operating business. These two freezing procedures help you achieve just that, but in different ways. With freezing, the temperature is decreased slowly, usually up to 24 hours. Deep freezing does the same in a much quicker time frame – typically, within an hour.
Here we explore the advantages and disadvantages of these two preservation techniques.
This is the traditional method to preserve food for extended periods. Every individual with a normal fridge performs this operation at home on a regular basis. The process is simple – the temperature of the product is reduced once into the freezer. It can take up to 24 hours for the core of the product to reach the -18ºC needed to preserve it.
During this process, the water contained in the products is transformed into big ice crystals. The size of these can have a huge impact on the food, making it lose its freshness, and losing vitamins and other essential qualities. The edges of the crystals can perforate the food cell wall, and products tend to dry out when frozen under this method.
With this technique, foods are quickly brought to a temperature between -30º C to -50º C until the product core reaches -18º C. This is a precise process used on fresh products and allows you to store safely, for a long period, nutritional characteristics of the food, especially fish and vegetables.
During the deep-freezing process, the water contained in the cells is finely crystallised, which ensures that dietary fibres are not broken, keeping the flavour and nutritional properties of the product.
The equipment used must be adapted and checked before deep freezing. It is necessary to be aware of the freezing capacity on the datasheet of your unit to make sure everything is performed correctly and, therefore avoid unwanted consequences like food poisoning.
Deep freezing, can cause serious food poisoning if the process is not performed correctly, it is therefore necessary to take numerous precautions to avoid this and to preserve the original quality of the products.
Safety precautions for deep-freezing
Food should always be cooled to 4 ° C before being frozen to avoid increasing the temperature of the chamber and cause electric consumption.
Once frozen, the products must be stored at a negative temperature varying from -9 to -18 ° C depending on the product. Remember to check the temperature and maintain your storage equipment.
It is better to deep freeze a fresh product rather than a product that has already started to spoil in order to preserve its qualities.
Basic hygiene rules still need to be adhered to even though we are working with low temperatures for although there are fewer microorganism or they become dormant some can survive at low temperatures. It is therefore essential to:
- Wash hands throughly and all food handling tools
- Wash the products
- Clean and disinfect the deep-freezer / storage system / cold room
- Use sealed freezer bags or suitable containers to protect the food while taking care to air vacuum and carefully close lids or bags
- Never refreeze a product that has been defrosted or during defrosting. Re-freezing a product which has been defrosted causes proliferation of bacteria. If they are pathogenic, they can cause food poisoning!
The shelf life of frozen foods varies from 1 to 24 months according to different food products. It is therefore essential to label them so as not to exceed the recommended expiry date.
Here are the best use before dates for the following food groups*:
- Fruits and vegetables: 24 months
- Pre-cooked potato products: 24 months
- Meat and poultry, whole or in portions: from 15 to 18 months
- Minced Meat: 12 months
- Sea food fished or farmed: 24 months
- Fatty fish: from 9 to 10 months
- Breaded Fish: 24 months
- Baked pastries, doughs and Viennese pastries: 12 months
- Raw Viennese pastries: 24 months
- Ready meals: from 18 to 24 months
- ice creams and sorbets: from 18 to 24 months
Diagnosing Common Problems with Freezers and Deep Freezers
Regardless of whether you have a standard freezer or a deep freezer, they often come with similar problems. Some of these issues are easy to spot, like a failure to get cold enough, while others may take longer to detect. Some of the most common problems Keller, TX residents find with their deep freezer or standard model include:
- High temperatures: A freezer that’s too warm clearly won’t keep your food frozen. Your thermostat may need repair from Ace’s Appliance Repair if the problem persists.
- Frost buildup: Occasionally, the cold in your freezer can result in frost buildup that requires some troubleshooting to fix.
- Water leakage: If you notice leaking water coming from your deep freezer, it may be a problem with the defrost drain or condensation pan. Either of these problems could call for a visit from the Ace’s Appliance Repair team.
- Strange sounds: Many household appliances, like your ice maker, cause some noise during its normal operation. However, if you hear out-of-the-ordinary noises, there may be a problem with your freezer’s fan.
- Malfunctioning electronics: If your deep freezer won’t run in the first place, it’s likely a problem with the electronic controls. If you can’t find a problem with the power flow, the controls themselves may need to be replaced.
Troubleshooting Freezer Problems, from Temperature to Leaks
Troubleshooting these common problems is much the same, whether you have a traditional freezer or deep freezer. Depending on the problem you’re experiencing with your appliance, you may need to try a few different methods to get everything back in working order. Ace’s Appliance Repair is your expert in freezer repair, and we want to share some tips on troubleshooting with the Keller, TX community. Before purchasing a costly replacement, try the following freezer repair techniques:
- Check for items that could be blocking the vents.
- Ensure that the temperature isn’t set too low, usually around 0 degrees Fahrenheit is optimal.
- Make sure the freezer door is closing all the way.
- Inspect the shutoff valve for leaks.
- Limit how often you open the freezer door.
- Ensure proper airflow by placing the back-mechanical room cover correctly.
- Check for power flow by operating the ice maker.
- Keep the freezer 70-85% full.
How to Care for a Deep Freezer That Is Not in Use?
A deep freezer that will not be in use for an extended period of time should be prepared for storage. Moisture and mold are the chief enemies of freezers that are put into storage. There are simple things you can do to care for your chest or upright freezer while it’s not in use so it can be stored safely and be ready when you want to use it again.
1.Prepare the freezer for storage by removing all food, turning the freezer’s cold control to “off,” unplugging the freezer and defrosting it. Drain or wipe up any defrost melt water. Take out any movable shelves.
2.Mix a dishwashing liquid solution in a bucket. Wipe down the outside of the freezer with a sponge dampened with the dishwashing liquid solution. Wipe down the inside of the freezer and shelves with the damp sponge. Wipe down the inside of the door and the door gasket. Pull on the gasket to open the folds so your sponge can remove any dirt from the folds inside and out. Wipe down the freezer’s interior again with a solution of 2 tbsp. of baking soda to a quart of water. Dry the interior with clean towels. Clean, dry and replace movable shelves.
3.Apply car or appliance wax to the outside painted metal shell of the freezer with a clean, soft cloth. Polish with another cloth. Don’t wax plastic parts. Remove dust or cobwebs from the compressor and any coils underneath the freezer with a vacuum cleaner and whisk broom. Block access to the compressor compartment with heavy cardboard or other material. Put a fresh box of baking soda inside the freezer to control odors.
4.If your freezer door closes with a mechanical latch, remove the latch handle or catch and store it inside the freezer. Most latches are held in place by screws. Wrap a safety strap around the freezer to keep the door from being opened by a child. Store the freezer in a garage or other protected area where it will stay dry. Cover with a sheet or tarp to keep off dust.