Blast Chiller Buyers' Guide
The most important aspect of any foodservice operation is food safety. There are many regulations and guidelines in place to prevent restaurants from serving unsafe food, and a blast chiller is a great way to meet those requirements. A blast freezer chills or freezes food quickly, moving it through the danger zone between 135 and 41 degrees F typically within four hours to limit bacteria growth. That chilling can be done much more rapidly than in traditional refrigerators and extend the shelf life of your chilled and frozen products.
Flash freezers are available in undercounter, countertop, and floor models, holding as few as three or as many as 40 full-size pans. Estimate how many pounds of food you will be chilling at once to decide how large a unit you will need, keeping in mind that each pan can hold a maximum of 10 pounds of food.
Always size up when possible, as you will likely find numerous uses for your chiller other than prepping food for cold holding. They allow chefs to set desserts, including ice cream, in a fraction of the time it takes in a regular freezer. Some restaurants use chillers to cool plates, wine, and bottled drinks. Sizing up also helps prevent overloading the unit, which can overwork the compressor and shorten its life, as well as making it take longer to chill the food. That's of particular concern, given mandates that food be taken from cooked temperatures to below 40 degrees F in less than four hours.
A blast freezer works similarly to a convection oven, essentially reversing the process. Where a convection oven uses fans to move hot air around the cooking cavity, a blast chiller blows cold air through the box to displace warmer air, using an evaporator coil to remove heat from the box in the process. Due to the power required for this process, flash freezers often have larger compressors and more powerful fans than most commercial refrigeration units.
Floor model blast chillers have the compressor mounted on the top or bottom of the unit. Because heat rises, top-mounted compressors are best suited for cooler kitchens where they won't be made less efficient by excessive hot air. Because they're away from the dust and abuse of the floor area, these generally require less maintenance. By contrast, the coils of bottom-mounted compressors may become clogged by those particulates, which can cause them to work harder, require more maintenance, and even shorten the life of the unit. Still, the lower location makes them easier to access, so cleaning and service are simpler to complete. They can also prove more efficient in hot settings and typically have a lower initial price tag.
Undercounter and countertop models often use side-mounted compressors. These are easy to access when they need to be cleaned and for maintenance, but they take up more horizontal room and may require additional clearance from nearby walls and equipment.
Another option is a remote compressor, which is installed on the roof or somewhere else outside your building. Because the large size of a blast freezer's compressor can add a lot of noise and heat to a kitchen, using a remote compressor can keep your kitchen more comfortable. However, the installation of a remote system can be expensive.
Flash freezers can make meeting HACCP guidelines easier, and some models can even help you with keeping records. In many cases, temperature is tracked by a probe inserted into the food that can let you know how quickly it reaches safe temperatures. Some units also record and save temperature logs for you to export later via USB drive or internet connection. The models that include Ethernet connections can upload records, send you alerts, and allow you to manage equipment remotely.
For high-volume operations, roll-in blast chillers are available. These allow you to roll an entire pan rack into the chiller at once without having to individually load each pan. While blast freezers are not intended to hold products for long periods of time, some do include a freezer holding setting that will store foods until you are able to move them to another refrigeration unit.