Everything You Need to Know About Batch Freezers

Everything you need to know about batch freezers. In this post, I want to talk about the heart of the ice cream-making process – the batch freezer. When it comes to ice cream making, a batch freezer is where “all the magic happens”. It is what takes a liquid mixture and makes it into ice cream. It is the most important piece of equipment for any ice cream maker. That’s why if you want to make great ice cream you need to become an expert in what batch freezers are and how they work.

That is why in this post I am going to cover everything you need to know about batch freezers including what is a batch freezer, maintaining and cleaning a batch freezer, how much they cost, and common troubleshooting questions.

But first, what do you exactly need to know about batch freezers?

What Is a Batch Freezer?

A batch freezer is a commercial ice cream machine used to make ice cream, gelato, sorbet, sherbet, frozen yogurt, and frozen custard. Batch freezers work by simultaneously freezing and whipping air into the frozen dessert mix. Batch freezers tend to be simple to use, clean and maintain.

How To Read This Post?

I have divided this post into four sections

A. What Is A Batch Freezer?

B. Batch Freezer Maintenance And Cleaning

C. How Much Does A Commercial Batch Freezer Cost?

D. Commercial Batch Freezer Trouble Shooting

Everything you need to know about batch freezer - extraction

A. What Is a Batch Freezer?

As a general rule, a batch freezer is a commercial freezer used to make scooped ice cream and gelato. It works by simultaneously freezing, whipping, and scrapping ice cream in a confined space. There are various types of batch freezers – horizontal, vertical, continuous, and batch. However, whatever the style, almost all types of frozen desserts are made using a type of batch-freezing method. The main exceptions are frozen desserts like soft serve ice cream which use a soft serve machine or for example, some hand-churned ice creams that use ice and rock salt, and nitrogen ice creams.

If you want to learn more about soft serve machines and how they work, I dedicated a whole post to them you can read here: Everything You Need To Know About Soft Serve Ice Cream.

How Does a Batch Freezer Work?

A batch is a simple mechanism. An ice cream mixture is inserted into a sealed metal cylinder chamber. Inside the cylinder, there is a set of beaters and scrapers attached to a turning mechanism. Once the batch freezer is started it will begin to freeze the outside of the metal cylinder. As the cylinder gets colder the ice cream mixture will start to harden and freeze on the sides of the metal cylinder.

As this happens the beaters will be doing two things.

Overrun and Whipping

First, they will be spinning at anywhere from 130 to 230 RPM. This will whip the ice cream mixture and add in air. This is known as “overrun”. I covered in detail what you need to know on overrun in my post What Are The Different Types Of Frozen Desserts. If you want to know more specifics about overrun, please read that post.

For now, you need to understand that the more overrun (aka air) that is whipped into the ice cream the bigger its final volume will be. This ability to create a bigger volume of final ice cream than the initial mixture is one of the reasons that ice cream can be so profitable. It can also help create a lighter and smoother ice cream texture.

Scraping

The second thing your batch freezer will be doing is using the beaters to scrap the ice cream off the cylinder as it freezes. This constant freezing and scraping will allow all the ice cream mixture in the cylinder to freeze. It will also help prevent the formation of large ice crystals during the freezing process.

The key to any creamy or smooth ice cream is tiny ice crystals. For a super-luxury ice cream feel you want to make sure the ice cream has lots of super tiny ice crystals. The batch freezer churning and scrapping helps to create this situation.

How Do You Use Batch Freezer?

How do you use a batch freezer? The below list is the step-by-step process of how a batch freezer is used and works:

the batch freezer is put together and some food-safe lubricant is put on the end of the shaft to prevent damage from friction.

food-grade sanitizer is poured into the cylinder of the batch freezer and the beater blades are turned on for a minute. This is to sanitize the machine.

the sanitizer is extracted and poured away.

the batch freezer is left to completely dry free of any sanitizer solution.

ice cream mix is poured into the cylinder and the machine is turned on to freezing mode.

the cylinder starts to freeze and so does the ice cream in contact with the cylinder. The ice cream beaters then scrape the ice cream away to make way for some more ice cream mixture to freeze. The process repeats until all the ice cream mixture has been frozen and scrapped into ice cream.

In about 10-15 minutes the ice cream batch will be ready to be extracted.

the ice cream is then extracted from the batch freezer and place into ice cream buckets ready for storage or serving.

What Is Overrun in Ice Cream?

As a general rule overrun in ice cream is the air that a batch freezer whips into ice cream. A lot of cheaper ice cream brands have overrun by up to 100%. That means there is as much air in each scoop as there is ice cream. However, super-premium ice cream has an overrun of less than 50%. The lower the overrun the creamier and denser the texture and mouth full.

Can I Control Overrun?

It is extremely difficult to control the amount of overrun you get from a batch freezer. There are ways of trying to control overrun. You can increase or decrease the RPM of the beaters. Similarly, tweaks to recipes can change the amount of overrun in an ice cream mixture. When it comes to overrun, however, getting the right amount can be more of an art than a science. It is something you get through trial and error.

What Is a Gelato Batch Freezer?

A gelato batch freezer is the same as a commercial batch freezer. Batch freezers can be used to make both ice cream and gelato, as well as frozen yogurt, sorbet, sherbet, and frozen custard. If you want to read more about the different types of frozen desserts, you can here – What Are The Different Types Of Frozen Desserts.

Everything you need to know about batch freezer - horizontal

What Are the Main Brands of Batch Freezers?

The main brands of batch freezers include:

If you must pick a brand, I personally recommend Emery Thompson. They produce, in my opinion, the best ice cream batch freezers on the market. If you buy a second-hand one make sure to buy one with a blue logoed labeled and not a black logo label – these are the older models which contain lead and they are still kicking around.

What Type of Batch Freezer is the Best – Horizontal vs Vertical?

There are two main types of batch freezers – horizontal and vertical. This refers to how the cylinder is set in the machine – whether it is horizontal (where it is set on the side of the machine) or vertical (where it is set on the top of the machine).

There is a shifting debate on which style is better.

Vertical

Vertical batch freezers are traditional styles of batch freezers. Ice cream mix is loading directly into the top of the batch freezer, and you can directly see the freezing and churning process. The result is that you have more control over how the ice cream is frozen (because you can see it being made), you can also more easily add mix-ins or chunks. The main disadvantage is that these types of machines produce less overrun as gravity pushes down on all the ice cream mixture).

Horizontal

Horizontal batch freezers tend to be the more modern style of machines. The freezing cylinder is on the side of the machine. As a result, they must be sealed tight with a heavy door. Ice cream is then poured into the cylinder via an access hole in the cylinder door. Because of the sealed nature, you won’t be able to see how the ice cream is freezing until you extract it. It also means any mix-ins or chunks must be added after the ice cream has been extracted. Overrun and quality tend to be better in these types of machines.

Everything you need to know about batch freezer - extraction 2

B. Batch Freezer Maintenance and Cleaning

How Do You Maintain a Batch Freezer?

In terms of pieces of equipment batches freezers, in my experience, are some of the simplest and easiest to learn, maintain and use.

However, there are a few maintenance tips to ensure the best performance from your batch freezer. These are as follows:

Lubrication: You will want to use a food-safe lubricant each time the batch freezer is used. This is usually placed at the end of your whipping shaft (the part that slots into the bottom of the freezing cylinder). This will help to prevent any damage to your machine from the friction caused by spinning.

Condenser Cleaning: You will want to regularly open and clean the condenser coils of your machine. This is to remove any dust or debris which may be blocking airflow into your machine.

Scrapers: Scrapers can file down over time or become blunt. You want to make sure your scrapers have an edge so they can effectively scrape off ice cream. New scrapers may need to be purchased yearly or old scrapers can sometimes be sent back to manufacturers for sharpening.

Seals: O-rings and seals can wear out over time. Periodically you will want to replace these when necessary.

Taking Apart Your Door: you will want to regularly (at least 2 to 3 times per week) take part your door so that you can easily clean and sanitize the parts that are hard to get to. Your manual will show you how to do this.

Reliability

Not to tempt fate, but batch freezers have been extremely reliable pieces of equipment for me. For example, I bought a second-hand batch freezer 3.5 years ago and have not had to carry out any major repairs on it. During its life, this machine has produced over a million dollars worth of ice cream.

In comparison, I had two soft serve machines for 2 years and the maintenance and repairs on the machines were high (you can read more about it here – Everything You Need To Know About Soft Serve Ice Cream).

How Often Do You Clean an Ice Cream Machine?

As a general rule, you want to clean out a batch freezer after each type of flavor has been made. This is to prevent: (a) cross-contamination; and (b) one flavor affecting another.

For example, if you must make 5 batches of Vanilla ice cream and 5 batches of Chocolate ice cream in one day. You will want to wash the machine out between making the two flavors.

The exception is when you make ice cream flavors that are increasing in flavor strength and have similar ingredients. For example, if you are making a vanilla ice cream, and then a mint choc chip ice cream. Or a chocolate ice cream followed by a chocolate mint ice cream. In these instances, one flavor can be made after another without washing out the machine. This is if the ice cream is made one after the other without any long breaks.

If you made chocolate ice cream in the evening and wanted to make chocolate ice cream again in the morning you would still have to wash the machine out that evening after making the chocolate ice cream. You cannot leave a batch freezer un-washed for several hours and then use it again without washing it. Batch freezers are not designed for food-safe storage.

How Are Ice Cream Machines Cleaned?

Ice cream batch machines are simple and easy to clean. A commercial ice batch freezer can be cleaned in the following steps (this will be true for most types of batch freezers):

Extract all remaining ice cream from the batch freezer.
Pour water into the cylinder and turn the beaters on for one minute. Extract water. Repeat with fresh water until all the ice cream has been extracted from the machine.
Take apart the machine and wash and sanitize all the parts and leave them to dry.

Ice cream batch freezers are very easy to clean compared to soft-serve machines which are much more difficult and time-consuming to clean. If you want to read more about how to clean and maintain a soft serve machine you can here – Everything You Need To Know About Soft Serve Ice Cream.

How Long Does It Take to Clean an Ice Cream Machine?

On average, it can take as little as 10-15 minutes to clean an ice cream machine. This will vary based on the size of the machine. It then takes an additional 5 minutes to put the ice cream machine back together.

A commercial batch freezer is quick to clean and put back together. In comparison, a soft-serve machine takes a lot longer to clean and put back together.

For example, my Emery Thompson 6-quart machine takes around 10-15 minutes to completely clean, and sanitize.

C. How Much Does a Commercial Batch Freezer Cost?

The cost of a commercial batch freezer depends on the brand, features, ice cream output capacity as well as if it’s new or used.

As a general rule, a tiny capacity batch freezer can be purchased for as little as $1- $2k. On the other end of the spectrum, a new top-of-the-line and high-capacity batch freezer can cost the best part of $50k.

The first batch freezer I bought was a used 3-quart Taylor counter-top batch freezer I bought for $2.5k on Craigslist. The second machine I bought was a used 6-quart capacity Emery Thompson machine I bought from a secondhand ice cream machine supplier for $7.5k.

Powering a Batch Freezer

A lot of batch freezers will require three-phase wiring or similar. This is to make the machines more efficient. This means you may need to have specific wiring installed for your batch freezer to work.

Batch freezers do use a lot of energy. However, because they are used for short specific periods of time it should not adversely affect your energy bill too much.

D. Commercial Batch Freezer Trouble Shooting

What Happens If You Churn Ice Cream Too Long?

If a batch freezer is left in freeze mode for too long, then the ice cream will be over-churned and over frozen. The ice cream will become so thick the machine will just stop unable to move the frozen mixture. This problem can be worse depending on whether the machine you use has a pre-set timer that will stop the freezing process after a time limit or if everything must be stopped manually. My Emery Thompson for example must be stopped manually.

When this does happen, you must turn off the machine immediately and wait 20 minutes or so for the ice cream to soften. Batch freezers produce a lot of heat, so this process never takes long. After that time the ice cream will be soft enough to be churned and extracted.

What Does Beater Overload Mean?

If your batch freezer comes up with the message “beater overload” then it means that the ice cream mixture has become too thick or hard for the beater to churn. Your mixture is either too thick (unlikely) or it has been frozen so much it has become hard. As above, you will have to turn the machine off and wait 20 minutes or until the mixture is soft enough to be extracted.

Why Is My Ice Cream Not Freezing?

The time it takes ice cream to freeze depends on the ice cream recipe. A more liquid ice cream mix will take longer to freeze than a thick creamy ice cream mix. This is particularly the case with water-based sorbets – they may not freeze in the batch freezer after 10 minutes and may need to be left for longer (up to 15 minutes) for it to freeze.

Sugar content also affects the frozen dessert mix’s ability to freeze. The higher the sugar content the longer it will take to freeze. This means a high sugar content fruit and water-based sorbet will have to be left for longer in a batch freezer to freeze than an ice cream based made with whole milk and cream with low sugar content.

My Batch Freezer Is Churning but the Compressor is Not Turning On?

If your batch freezer is churning but the sound of your compressor is not coming on, it most likely means that your compressor’s safety switch has been tripped. If a compressor overheats or works too past its limits, then usually a safety switch will be tripped. This will shut down the compressor. When this happens let your batch freezer cool down for a period (around 1 hour) and then reset the safety switch. Consult your manual on where this can be found.

My Batch Freezer Produces So Much Heat?

Batch freezers produce a lot of heat and are often air-cooled. To operate them you want to have a lot of open space around the machine. Despite this, a batch freezer running for long periods will increase the temperature of your kitchen.

If a batch freezer gets too hot (which can happen in the summer months) it can take longer to make ice cream and/or stop running. To help keep our batch freezer cool and with enough air, we have a dedicated commercial fan blowing at it when it is in operation.

Everything you need to know about batch freezer - the final lick

Everything You Need To Know About Batch Freezers – The Final Lick

Everything you need to know about batch freezers. Batch freezers are one of the MOST important purchasing decisions you will make for your ice cream business. When you do decide to purchase a batch freezer you want to make sure you get one that can deal with your production needs. Get a too-small one and it will be impossible to keep your ice cream store running. Get one too big and you will be paying for something you don’t need. As a general rule, any type of serious ice cream operation (such as an ice cream shop or truck operation) will want a minimum of a 6-quart to 12-quart ice cream machine. A 6-quart is what I use to run my ice cream operations. If you have space even two 6-quart machines might be a good idea. That way you always have a backup and can be running two at once doing different flavors.

Lastly, make sure to look after your batch freezer. Because it is your most important “team member”.

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