The Big Chill: Challenges of Cost-Effective Food Freezing

Thawing out the mechanical vs. cryo debate

When it comes to food freezing, there are generally two main options to choose from: mechanical and cryogenic. Mechanical systems use a refrigerant in a closed cycle. These systems move large quantities of air to freeze the product. Cryogenic systems, on the other hand, use nitrogen and CO2 to freeze the product. And, while the vast majority of facilities choose mechanical, Airgas’ food, beverage and retail experts Bill Baker and Bill Adams say there are several factors that may make you consider cryogenic.

• What are you trying to freeze? The type of product can determine which mode of freezing makes the most sense. Chopped and formed proteins, for example—like burger patties or chicken nuggets—have a better appearance when frozen cryogenically. For vegetables and other products with lower price points, however, mechanical freezing should do the job just fine.
• Is moisture loss a concern? If moisture loss is a concern, cryogenic may be the system for you. Cryogenic freezing loses less moisture because of decreased air movement. This can save up to 5% of the product weight. Products most impacted by moisture loss include shrimp, diced poultry and cooked fillets.
• Is time of the essence? Keep in mind the time it takes to freeze the product. Cryogenic systems typically freeze much faster than mechanical.
• How much room do you have? Cryogenic systems take up significantly less space than mechanical systems, so space could be the determining factor here.
• What else is there? Consider what is already onsite. For example, if there’s already an ammonia tank onsite, you could tap into it to gain added efficiencies.
• How long will this product be offered? The consumer is fickle these days, so it’s important to take into consideration how long you’ll be running this product. If it’s short term, cryogenic is likely a good choice because it requires less capital.