Blast freezing is the process of pushing cold air at high velocity across a food product in order to freeze the product as quickly as possible.  Blast freezers come in a variety of configurations, from single-load freezers that freeze batches of products, to “continuous” freezers such as tunnel freezers that continuously freeze product as it moves through the freezer on a conveyer belt.

The primary goal in blast freezing is fast freeze times.  Fast freeze times are important for a number of reasons – the most obvious being production efficiency – getting the most production out of the least amount of production space is important in every industry.  However, the most compelling motivation is the economics of quality.  High quality food products can be pushed into high price markets, but low quality products are left to the low price markets – plain and simple.  Blast freezing is an effort on the part of frozen food producers to preserve as much of the quality as was present in the raw product as possible in order to position their products before the type of customers that are willing to pay the most for the very best quality.

But what do freeze times have to do with preserving quality?  What are the elements that make for great blast freezing equipment?  Are there ways of improving the freezing effectiveness of existing equipment?  These are fundamental issues important to every frozen food producer.

Freezer types and their applications

Some freezers are better suited for certain applications than others depending on product type, process conditions or quantity. To ensure the best quality product, it’s important to choose the freezing equipment that creates the most efficient freezing process for your specific product. Below are several types of freezers and their typical applications:

— Process freezer — Process freezers are typically incorporated into the manufacturing line for cooked products, situated between cooking and packaging.

— Individual Quick Freeze freezer — IQF freezers can be mechanical, but are most often cryogenic systems. They’re ideal for protein served in small pieces such as diced ham, wings, meatballs or shrimp. They can also be used for fruits and vegetables and prepared foods like pizza or pasta.

— Spiral freezer — Spiral freezers can be either mechanical or cryogenic, and move the product along a spiral conveyor through a room for about 45 minutes until it is frozen.

— Tunnel freezer — Tunnel freezers work in the same fashion as spiral freezers, but they move the product linearly, rather than in a spiral pattern.

— Plate freezer — A plate freezer is a special hollow plate that has liquid refrigerant flowing through it. Products are placed between two plates and evenly cooled to freezing temperatures. These freezers are ideal for flat products or brick-shaped packaged products, such as frozen meals.

— Blast freezer — Blast freezers are mechanical systems generally used to freeze products in bulk on pallets. Blast cells are not part of the manufacturing line like process freezers. The food is sealed in a blast cell and remains there for multiple days as cold air is continuously circulated throughout the room.

When selecting the proper freezing equipment, it’s helpful to work with a refrigeration equipment provider to determine which system is best suited for the specific product. Often times, food plant owners can work with providers to create a custom-designed system to fit their needs perfectly.