How Does a Blast Chiller Work?

A blast chiller works by blowing cold air over the surface of foodstuffs. The exact mechanics of the cooling effect are slightly more complex, however. The first thing to know - if you’re looking for a more complete understanding - is that a blast chiller’s cooling-efficiency is optimized by circulating an uninterrupted flow of cold air throughout its internal cavity.

Another factor to consider is the spacing of trays within a blast chiller. You see, larger gaps just so happen to be more conducive to promoting airflow. This is critical since once air stagnates it has a tendency to warm up. Not what you want from a blast chiller. As such, blast chillers are purposefully designed to have airflow-promoting spaces between trays.

Multiple Settings

Blast chillers are versatile and typically have a number of settings to accommodate different needs. For example, there is often a soft chill setting, which is ideally suited for chilling delicate foodstuffs such as salads. Likewise, there is commonly a hard chill setting, which is better suited for chilling foods which are relatively high in fat. What’s more, oftentimes there is also a shock freeze setting, which works best for high-risk foods.

Different Blast Chiller Models

At the get-go we asked; what is a blast chiller? Well, it just so turns out that it can be a number of things. You see, blast chillers are available in a number of different configurations. For starters, there are low profile models, which are specifically designed to fit under a combi oven. In a professional kitchen, this means that food can be passed straight from the oven into the blast chiller. Generally, low profile models have a maximum capacity of somewhere between 35lbs and 48lbs.

Reach-in models are designed to accommodate the class of food pan rack assembly typically seen in large combi ovens. Reflecting this, reach-in models have a much greater maximum capacity (220lbs) than low profile blast chillers do.

The roll-in and pass-through models are bigger still. Each of these can accommodate in excess of 500lbs of food.

Why is Blast Chilling So Useful?

Bacteria proliferate between 8/46℉ and 68/154℉. Given this fact, blast chillers are designed to reduce the core temperature of cooked food from 70/158℉ to 3/37℉ within 90 minutes. Thanks to this ability to rapidly cool foods, blast chillers play an invaluable role in reducing the risk of contamination.

Blast chilling food also reduces the number of ice crystals that develop on food. Large ice crystals are considered problematic because they release excess moisture and rupture cells during the defrosting process. This has a negative effect on the quality and taste of food. Since blast chilling produces only very small ice crystals, food integrity is much better preserved.

Advantages and Disadvantages of Blast Chilling

Blast chillers do more than just reduce ice crystal formation and dial down the risk of contamination. They also have a number of other selling points.

• The blast chilling process encourages what is known as an ice skin to develop on food. This frozen layer helps protect delicate foods such as soufflés or fruit extracts from damage.

• Blast chillers generally have a number of different compartments. As a result, the risk of cross-contamination occurring is relatively low.

• Since, in most cases, blast chillers are relatively large, they also happen to offer plentiful storage. This is a boon as when allied to a blast chiller's capacity to preserve food ample storage equates to less waste.

• Having a blast chiller on hand frees chefs up to prepare meals in advance and to store them without compromising on taste, appearance, or texture.

There are, however, a couple of downsides to blast chillers. Firstly, they aren’t exactly cheap. However, in fairness, the hefty initial outlay typically pays dividends over the long run in terms of labor and food savings. The second downside of blast chillers is that they are incredibly energy-hungry devices.