What to Look for in Blast Freezers for Food Processing

John A1 week ago

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What to Look for in Blast Freezers for Food Processing

Blast freezers are essential in food processing for preserving freshness and preventing bacterial growth. But not all freezers are built the same. This guide walks you through the key features to consider when choosing a blast freezer for your facility.

Every industry has one quality or trait that is necessary for its success. In the food processing industry, that is freshness. The freshness of, say, a hunk of cheese impacts the overall consumer experience, and the retail shops, restaurants, cafes, and more.

A perfectly fresh batch of cheese increases sales, which also increases the demand on the cheese-making factories and vice versa. But how does the cheese industry, or the food processing industry for that matter, keep its food fresh?
It does so with the help of blast freezers. But what are these devices, and how can you choose the right one as a food processing executive? Let’s explore that below.

What Is a Blast Freezer?

A blast freezer is used to cool and freeze food in a span of a few hours. They are used to cool down freshly cooked food, raw seafood, and freshly prepared products like cheese.

They are also known as shock-freezers.

Using them can help you:

Keep your food fresh by restricting bacterial activity
Maintain the quality of its texture, shape and taste prior to its export or distribution.
Increase the lifespan of the food
Maintain compliance with the prevailing food safety regulations, like Chapter 3 of the Food Standards Australia New Zealand, for example

Now, let’s study the factors that will help you choose a shock freezer below.

Which Key Features Should You Look For in a Blast Freezer?

You should look for the following features when you consider which shocker freezerto purchase for your freezer room:

Freezing Capacity and Cycle Speed

The freezing capacity of your shock freezer refers to the physical quantity of food that it can freeze within a given time. It is generally measured in kg per hour or kg per cycle.

This value depends on the size of the freezer, the kind and quantity of food, and the temperature maintained inside the freezing area.

Cycle speed refers to the time a blast freezer takes to cool the dish in question. Generally, a blast freezer should not take more than four hours to cool something, as per HACCP regulations.

You should consider the daily load of the food item you’re manufacturing before making your decision. For example, if you were working in a small-scale plant that made 50 kg of cheese per day in a 5-hour shift.

You would then require a freezer that could shock freeze 10 kg of cheese per hour.

Temperature Range and Hot Pull Down Power

A blast freezer’s temperature range refers to how cold it gets when it operates. This ranges between minus ten degrees Celsius to minus one hundred twenty degrees Celsius. The temperature range of the shock freezer impacts how fast it cools the food.

This speed also impacts the overall efficiency of the food processing plant. That’s because a new batch of food cannot be frozen unless the previous batch is taken out.

Apart from that, the freezer’s capacity to bring down the temperature of hot food (hot pull-down) also impacts the food’s freshness.

Airflow and Fan Technology

A shock freezer with uneven distribution or flow of air will be unable to freeze the food properly. This could affect the texture, taste, and quality of the food for people.

That’s why you should place the food to be frozen in trays to ensure even spacing and cooling.

Take a look at the diagram denoting the placement of food to be frozen on the tray inside a shock freezer below:

Diagram 1: Placement of food to be frozen inside a shock freezer

The air flow of a blast freezer is determined by the type of fan it uses.

You’ll find that shock-freezers either use:

Centrifugal fans (if you use tunnel shock-freezers)
Axial fans (if you use stationary shock-freezers)

Out of the axial fans, the vane axial fans are the ones that increase the airflow to reduce the time spent freezing the food.

You should check whether the shock freezer you buy has this fan or not.

Insulation and Panel Material

The material used to insulate the shock freezer also impacts its ability to freeze food. You should look for either PIR or PU-insulated panels. These materials are valued for their excellent fire-resistant and thermal insulation.

Another thing you should look for is a stainless steel body, since it is corrosion-resistant and highly durable. These materials will ensure that you can use the blast freezer for many years without replacing it.

Control Systems and Monitoring

Having a smart shock freezer will help you streamline your operations. That’s why you should look for a shock freezer that has a controller with a digital screen. The screen will display all the relevant information, like cycle speed, freezing capacity, and other parameters.

Your shock freezer should also have a facility to be connected to a Programmable Logic Controller. This will ensure that the PLC will adjust factors like the airflow and the temperature by reading inputs from the temperature and airflow sensors.

You should also check whether or not your blast freezer has a facility for automatically recording and storing temperature. These records will help you be compliant with regulations like those of the Food Safety Australia New Zealand.