What Is a Blast Chiller & How to Use It

A blast chiller is a specialized piece of refrigeration equipment designed to cool product rapidly from above 140 degrees Fahrenheit to below 41 degrees Fahrenheit, reducing the time food spends in the danger zone. In addition to ensuring food safety regulations are followed, blast chillers can optimize product quality and improve workflows in commercial kitchens. Below, you'll find more information about how blast chillers work and tips for choosing the right one for your foodservice operation.

What Is a Blast Chiller Used For?

Chilling cooked food improperly can keep it in "the danger zone" – between 140 and 41 degrees Fahrenheit – long enough for illness-causing bacteria to grow. However, making each product in a commercial kitchen from scratch when it's ordered would be an inefficient use of labor and equipment and make it impossible to plate and serve food as quickly as guests expect. On top of that, fresh ingredients won't store as long as prepped and frozen ingredients, increasing product loss over time.

To address these operational and food safety concerns, many venues – such as hotels, cafeterias, restaurants, creameries, and cruise ships – use blast chillers to streamline bulk food prep and handling. Unlike a standard freezer or refrigerator, a blast chiller isn't used for long-term or bulk storage of refrigerated or frozen goods. Instead, hot, fresh food is placed in a blast freezer to chill or freeze it as quickly as possible. Then, once it's reached the desired temperature, the food can be moved into long-term refrigerated or frozen storage.

Most blast chillers can hold multiple pans of food for bulk chilling, making them a vital component in large-scale food prep. Prepping and par-cooking food ahead of time shortens the cycle of ordering, cooking, and serving meals once a restaurant opens.

However, chilling a large volume of par-cooked food can be difficult, and a standard refrigerator or freezer may not be able to bring the food down to a safe temperature within the required time frame. Using a blast freezer during the prepping and storage cycle lengthens product life span and reduces the danger of foodborne illness when compared to other types of refrigeration.

Here are some common uses for blast freezers in a commercial setting:

• Fresh seafood: Flash freezing food preserves its texture and flavor better than other forms of freezing. This is especially important with delicate seafood, including sushi, oysters on the half shell, and other items that are served raw.
• Blanched or steamed fruit and vegetables: Produce that's been blanched or steamed and then frozen retains its color, texture, and flavor well. It resists spoiling and can be thawed quickly and cooked later. Locations that make jams and jellies, for instance, may use a blast chiller to preserve a large shipment of fruit for canning throughout the week.
• For baking: Using a blast chiller for baking enables operators to prepare large batches of dough or baked goods and preserve them for later use. Pastry dough that contains a lot of butter (such as short crust and laminated dough) is also particularly susceptible to warm temperatures and can lose its texture within minutes if the fat starts to melt in a hot kitchen. Placing pastry dough in a blast chiller between mixing, kneading, and folding the dough keeps it cold throughout preparation.
• Ice cream and sorbet: When ice cream and sorbet aren't served straight from the machine, they must be packaged immediately to prevent melting. After the fresh product is dispensed into large containers, it's often placed in a blast freezer to drop the temperature even lower and firm it up for handling and transportation.
• High-volume foodservice: Institutional facilities often prep large volumes of food well in advance of when it is served. Using a blast chiller, cooked food can be chilled, portioned, and stored promptly for retherming at a later date.
• General food prep: Large batches of uncooked food – such as eggrolls, breaded chicken tenders, and fresh pasta – can be prepped in advance and then frozen and stored for use throughout the following week or month. Each day, chefs can thaw what's needed and have it ready for cooking at a moment's notice.
• Stock, broth, soup, and stew: Some foods take longer to chill than others, especially large pots of hot liquid. This kind of product can be portioned into multiple hotel pans and placed in a blast chiller to move it quickly through the danger zone and reduce bacterial growth.

How Does a Blast Chiller Work?

Just as convection ovens circulate hot air to speed up cooking time, blast chillers circulate freezing cold air to hasten chilling time. The unit's refrigeration system is activated once food is placed in the chiller, simultaneously drawing heat out of the cabinet and circulating cold air around product until it's chilled below 41 degrees Fahrenheit.

Because this equipment freezes food so quickly, it creates smaller ice crystals in the food than a regular freezer does, minimizing cellular damage to product. Large ice crystals disrupt the food's texture and draw water out of the product, making it soft and damp when it's defrosted. Small ice crystals minimize this effect so food that's rethermed or thawed and then cooked retains almost the same taste, texture, and appearance as fresh food.

Blast Chiller vs Freezer

Standard commercial freezers don't circulate air the way blast chillers do and can't cool items as quickly. A freezer is meant to maintain the temperature of pre-frozen products during long-term storage; if it operated like a blast freezer, it would consume significantly more energy, raising operational costs.

Because a freezer is typically used for long-term, bulk frozen good storage, adding warm product to the freezer is a bad idea. The product will not only cool down slowly, but also raise the temperature of surrounding products, potentially causing them to thaw and refreeze slightly. Over time, this can degrade product quality and increase the danger of bacterial growth.

The same effect applies to refrigerators as well. The best way to chill and store food is to use a blast chiller to cool it quickly to a safe temperature, then move it into a refrigerator or freezer.

Blast Chiller vs Flash Freezer

A blast chiller rapidly chills food to below 41 degrees Fahrenheit, while a flash freezer rapidly chills food to below freezing. Most blast chillers can be adjusted either to chill or freeze food, depending on the product, so the terms blast chiller and flash freezer often are used interchangeably.

How Cold Is a Blast Chiller?

Typically, a blast freezer's upper temperature limit is 40 degrees Fahrenheit, while the lowest temperature setting can be anywhere from 5 to -5 degrees Fahrenheit. The starting temperature, density, and type of product can affect chilling times, as well as whether the product is being refrigerated or frozen. Most models can chill hot food below 40 degrees Fahrenheit within 90 to 120 minutes, which is well within HACCP guidelines.

Temperature settings, cooling speed, and other features can vary from model to model, so verify the model you're looking at meets your requirements before purchasing it. It's also a good idea to check local food safety regulations, as these can vary from state to state.

How Much Is a Blast Chiller?

Commercial blast chiller prices can fluctuate depending on the unit's size, cooling system, controls, and other features.

A small, countertop model with basic features can cost anywhere from $1,000 to $10,000. Larger floor models that can track multiple batch temperatures and chill hundreds of pounds of food at once may cost $40,000 or more.

Choosing a Blast Chiller for Your Commercial Operation

There are several considerations to keep in mind when comparing blast chillers.

Size. Think about how much product you'll need to chill, and how often. Decide if a countertop or floor model is better for your needs and where it can be installed. Measure the space available to ensure you select a model that fits your kitchen's floorplan and workflow.

Electrical Connections. Blast freezers come in different voltages and phases. Altering your building's electrical system or converting the unit in the field can be very costly, if it's even possible.

Features. Some models activate automatically when food is added to the unit, while others can be controlled manually. Many blast chillers include integrated temperature probes so users can track multiple batches of food as it's chilled. Some provide HACCP-compliant temperature logging, simplifying record keeping.

For large-scale operations, you might opt for a roll-in model, enabling employees to move hundreds of pounds of product quickly in and out of the unit with the use of rolling food racks. If space is limited, an undercounter model can provide bulk storage with a low profile that leaves the unit's top free for light prepping or serving tasks.

Spending some time up front to determine all your venue's unique requirements and choose the best-fitting model can save a lot of time, money, and hassle later.