What Is A Batch Freezer And How Does It Work?

Posted on Jul 01, 2017

carpigiani LB 502 batch freezer with carpigiani lb 302 RTX scene of fancy bar with chocolate hard ice cream and emerymark em40 and electro freeze b24 batch freezer

There are many creatively exquisite chefs around the world that use certain kitchen equipment even if they don't fully understand how this equipment works. If you were to walk up to one of these chefs, with pencil & paper, & asked them how immersion circulators maintain accuracy or how a freezer works, they would most likely not know the answer. Inside the ice cream and Gelato stores, you can find that the most important piece of equipment, the batch freezer, is also the least understood piece of equipment.

Do you know how a batch freezer uses liquid product mix to create exquisite fresh & smooth frozen desserts?

Defining A Batch Freezer

A batch freezer is a machine used to commercially produce large volumes of ice cream, gelato, sorbet, frozen custard, and sherbet. In this freezer, the product mix (also called the base) is frozen and whipped simultaneously to create a smooth consistency in the frozen desserts we eat today. There are four different types of batch freezers: 1) multi-purpose, 2) regular horizontal, 3) all-in-one combination, and 4) open vertical.

In terms of volume output, the batch freezer is the perfect option for a small to a medium-sized business. This is because it allows you to produce different volumes of product. A small 115-volt ice cream machine designed for at home usage can only process a small amount of liquid product mix, but a batch freezer can process up to 6 gallons (24 quarts).

Comparing a batch freezer to a continuous freezer, the continuous freezer has no limit on the processing capacity & is very dynamic for any business type or size. The continuous freezer shaves the fine layers of the product mix inside the beaker and in turn produces a frozen dessert with a creamy and smooth texture.

Air Cooled Versus Water Cooled Freezers

One of the most commonly asked questions by our customers is "What is the difference between a water cooled machine and an air-cooled machine"?

"Water-cooled machines runs water through the compressor or condensing unit to cool it & an air-cooled machine blows air through the condensing unit."

- Joe Kearns, Slices Concession

One of the common misconceptions is that water cooled machines are wasteful, but they actually use a very small amount of water to cool the machine. Since air cooled machines expel the heated air out of the machine, it can raise the A/C bills as well as make the room very hot. If the room gets too hot with multiple air cooled machines running, this could cause the product to be made poorly.

There are other things like local governmental regulations to consider when choosing air or water cooled, which is why we recommend you read our article choosing an air cooled or water cooled machine for more information.

How Does A Batch Freezer Work?

batch freezer with glowing purple window showing air cooling system with fan and condensers inside ice cream machine

An ice cream batch freezer, much like a car, has a main engine which is called the condensing unit. The compressing unit uses Eco-friendly Freon & compresses it into a cold liquid. The compressed Freon is pumped into the freezing cylinder.

Inside the machine, there is a barrel (usually made of stainless steel or corrosion resistant materials) where the product mix is poured into. While the product mix is poured into the barrel, there are pipes, filled with a freon & water solution, that surround the barrel to freeze the product.

While the machine is operating, there are spinning blades inside the barrel used to whip the mixture & infuse it with air while freezing the product simultaneously. This causes the product to tap frozen air bubbles, therefore, giving the product a smooth texture as well as a firm structure. The air mixed into the product is called overrun and most batch freezers have an overrun level of 30%-35%. The faster the blade spins the smaller the ice crystals, this causes the texture of the finished product to be smoother. There are also machines that can help you compute the total overrun of your product but these machines are more expensive.

The blades spinning in the barrel scrape the frozen product mix off the wall before it crystalizes too much. This creates a consistent final product that has evenly proportionate ice crystals in the product mix. The blades that equip all the machines are usually made of heavy duty plastic (or other nonreactive material) which allows the blades to be in constant contact with metals so there is no chemical reaction that could cause a health hazard.

The Refrigeration Circuit

Inside the freezing cylinder are two main components which make up an ice cream batch freezer: the refrigeration system & the beater motor. To cool the product mix you need the refrigeration circuit which keeps the cylinder cool by transferring the heat away from the freezing cylinder.

The 4 Main Components

The compressor
Heat Exchangers: one warm (tubes that form part of the condenser) & one cold (which is the evaporator)
Expansion valve (this controls the cooling flow)

The warm refrigerant goes from the compressor to the expansion valve and into the cold heat exchanger. The evaporation causes a cooling effect in the cylinder, which freezes the product inside the barrel. The expansion valve makes sure that there are correct amounts of cool & warm refrigerant in the heat exchanger.

Temperature Control Technology

The inside of the machine doors are made of a material that insulates the cold inside the machine to better regulate the internal temperature of the barrel. The machine control systems for the freezing cylinder differs in each brand. Some brands use probes with electronic thermostats that are directly placed into the product mix. These temperature regulators monitor all of the temperature changes by rotating between hot and cold gas and reading the amps used to regulate product consistency.

Other Machine Options

Ice cream batch freezers range from sizes of half a gallon (2 quarts) up to 11 gallons (44 quarts). Some brand models can finish the process of making fresh product in under 20 minutes. Though most machines monitor the churning time, newer models can even stop the freezing process when serving product so that the product has 100% complete consistency when served.

What Batch Freezers Do We Recommend?

Carpigiani LB 502 & 302 G Based on the 4 batches per hour at 60% overrun, the LB 502 produces 19 gallons per hour & the LB 302 G produces 16 gallons per hour.
Electro Freeze FT-1 This floor/full standing model is designed to make premium quality frozen desserts in large batches.
Taylor C119 This full standing model has one cylinder capable of producing 8.5 quarts (8.0 Liters) which you can adjust the viscosity for smaller batches and consistency.
Taylor 104 This small batch freezer comes with a funnel where you pour the product mix into the machine which has one freezing barrel capable of producing 3 quarts (2.9 liters).