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.
Freezer or deep freezer? Which should you buy? What is the difference between the two? Either of these types of freezers will be your friend when that chicken goes on sale. Both will do a good job of preserving your leftovers, making sure your family eats nutritional meals without you having to spend all day, every day in the kitchen. But there are important differences to consider.
First, let’s get some terminological confusion out of the way. The terms “freezing” and “deep freezing” originally referred to two different methods of preserving food. Both processes freeze the food to the same temperature (-18 °C), but they achieve it in two different ways. With freezing, the temperature of the food is decreased slowly, usually up to 24 hours. Deep freezing refers to a process where the food is exposed to a temperature from -30 °C to -50 °C so that the core of the product reaches -18 °C within an hour. Deep freezing is a method typically used in industrial settings. It is considered to be better than regular freezing in allowing the food to preserve its freshness, texture and nutritional qualities.
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.
Safety precautions for deep-freezing temperature
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 micro-organism 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!
Deep-freezing: the ideal solution for businesses
There are a few procedures that need to be carried out carefully to achieve the best results with this technique. However, using a deep-freeze freezer helps you keep your standards when serving and selling food. Products don’t lose their freshness, smell, texture or vitamins, allowing you to plan more efficiently without having to waste or miss out on quality.