Published on Sunday, 30 June 2013
Written by The Editors
While refrigeration equipment keeps food cold, blast chillers take hot temperatures out of food.
Blast chillers quickly cool cooked food by decreasing product temperatures from 160 degrees F to 38 degrees F in 90 minutes or less. This process reduces the time food is in the danger zone of between 41 degrees F and 135 degrees F, thus limiting bacteria growth and keeping food safe.
This chilling method forms microcrystals on products, as opposed to evaporating the moisture, which can dehydrate food. By arresting the cooking cycle, the blast-chilling process retains food quality, appearance, nutritional value and flavor. Foodservice operators can safely store most blast-chilled product for up to five days.
Blast chiller capacities range from 30 to 1,300 pounds. Foodservice operators can choose between reach-in and roll-in models, with most utilizing 2-inch deep pans that accommodate about 10 pounds of product at once. Some blast chillers feature rack systems that correlate with cooking equipment, such as combi ovens.
Blast chillers have large compressors and offer either self-contained or remote condensing units. Some blast chillers have built-in electric defrost capabilities that eliminate condensation on the condenser coils, while other units must connect to a drain.
Although more complex than refrigeration equipment, with newer technology and control boards, blast chillers have become easier to use than in the past.
- Although foodservice operators commonly use blast chillers as an element of cook-chill production, these versatile units are suitable for a variety of other applications.
- Operators can use blast chillers to chill salad plates before serving.
- Foodservice operations with high-volume bar areas can utilize blast chillers to quickly cool wine and beer as needed. These units also can cool other beverages in a pinch.
- So long as the air does not blow directly over the product, set gelatin desserts in a blast chiller. This benefits high-volume operations such as schools, which can quickly chill gelatin desserts in about 20 minutes.
- Chefs can utilize this equipment to quickly cool hot product for easier handling.
- Determine the food volume before choosing the appropriately sized unit. The number of pounds the unit can accommodate at one time determines the blast chiller's size. Units typically use 2-inch deep pans that hold about 10 pounds of product. Failure to properly size the product to the pan may compromise the cooling process and food safety.
- Know the available space when specifying a blast chiller. Operators can choose from undercounter, countertop and standalone units, in addition to roll-in and reach-in models. High-volume operations are best-served with roll-in units or a blast chilling room built into a walk-in.
- Consider the menu when deciding the appropriate type of blast chiller. For example, a softer, more gradual chill process is suitable for delicate food, like bakery items. In contrast, meat and other heartier products can withstand a hard chill that brings food temperatures down to an almost frozen state more quickly.
- Blast chillers offer different data recording capabilities for HACCP documentation, with the method dependent on the model. A unit may utilize a printer that records information on paper, a data port that can upload reports to a computer or a USB drive for downloading temperature details on a portable storage device. Operators should consider which method will work best in their operation.
- Allow for on-site training to ensure that the staff know how to properly use the blast chiller.
- Verify power requirements, cord length and type to ensure proper outlet type and installation height.
- Determine how the unit will evaporate or drain condensate and specify a condensate evaporator or floor sink in the proper location, if necessary.
Specifying Mistakes to Avoid
- One common mistake operators make is utilizing too big of a pan for blast chilling product. This can compromise the cooling process, as the cold air won't properly infiltrate the center of the pan. Proper container sizing is key for quality results.
- When sizing a blast chiller and designating space for this unit in the kitchen, operators also need to determine if clearance around the unit is necessary for proper ventilation. So it is important to take the footprint into consideration when specifying the equipment.
- One of the biggest issues with blast chillers is that operators commonly underestimate the complexity of these units. Chilling product with these systems is much different than simply placing food in a refrigeration unit. As a result, accomplishing this process may be more challenging in foodservice operations with entry-level employees or high staff turnover. When educating staff that will work with this equipment, it is important to address how food should be sized, shaped and packaged prior to the chilling process.
- Always up size when specifying a blast chiller. If the foodservice operator estimates the need to chill 60 pounds of product, it's better to go for a 100-pound capacity, for example. That's because most operators find additional uses for these units and almost always wish they would have considered a larger capacity unit when purchasing.
- Consider remote refrigeration versus self-contained. Blast chillers can contain large systems that exhaust a lot of latent heat into a space, and operators can avoid this by using remote compressors, which will also reduce the amount of noise in the kitchen.
- Place blast chillers in a location that works in tandem with other cooking equipment and refrigerated storage. Consider flow and function to ensure smooth operation.
- Compare size, controls and operations of various chillers to ensure that the unit can handle the type of product and its projected volume.
New & Notable Features
- Operators can choose from a variety of options and features, depending on the blast chiller model. Some types provide an ultraviolet light that sanitizes the cabinet's interior.
- Units with DC connections, printers, extra probes and preprogramming features also are available.
When to Replace
Although blast chillers are more likely to break down without warning as opposed to showing evidence that failure is imminent, there are situations where a new unit is warranted.
- Inconsistent chill times: If the unit shows signs of performance degradation by not cooling as quickly or consistently, this may mean it needs replacing. Operators should first make sure a dirty condenser is not the culprit.
- Costly maintenance: When service calls become more frequent and repair costs start adding up, especially with an older blast chiller or a unit that has experienced heavy use, it is probably time to consider a new system.
- Changing capacity needs: If the blast chiller seems to have hit maximum capacity or is running 24/7, it may be time to replace it with a larger-sized model.
Maintaining blast chillers is important from a safety standpoint, since temperature consistency is key for HACCP reporting. Operators can take a number of steps to prolong the service life of these units and keep systems in safe operating condition.
- Keep condenser coils clean, not only to ensure the unit chills properly but also for optimal energy efficiency. There should be as much airflow as possible.
- Keep blast chiller probes clean of food product to allow for accurate readings and to avoid any potential food safety issues.
- Clean door gaskets to provide a tight seal. If warm air and moisture get inside the blast chiller, the unit will need to work harder to maintain proper temperatures.
- Wipe down the unit's interior and exterior with a mild soap and water after use.
- If drain lines are in use, keep them clean of condensate water to prevent backups.
- There is no Energy Star rating for blast chillers, which run hard for a short period of time.
- Blast chiller energy use varies, depending on the model. Because this equipment is designed to take product temperatures down quickly, more power is used to operate these systems compared with standard refrigeration equipment.
- Units are available with two independent cooling compartments, which provide greater energy efficiency, as smaller amounts of product can be chilled in a single compartment without cooling the entire unit.
- Although there have not been many developments in terms of increased energy efficiency, models with a mode that uses parameter modifications, which can help decrease energy usage, are available.
Editor's Note: FE&S thanks Eric Norman, FCSI, of MVP Services for assisting with this article.