Gravity vs. pressure-fed: What's the difference?
When selecting a soft serve ice cream or yogurt freezer, even within a given brand, there are usually a great variety of models to choose from. Just as most car companies offer a wide selection of vehicles catering to the varied needs of consumers, such is the case as well in frozen treats equipment. Setting aside production capacity differences for a moment, soft-serve or yogurt freezers are usually split into two categories: gravity-fed or pressure-fed freezers.
How to tell gravity-fed and pressure-fed freezers apart
In most cases, you can distinguish the two main types of freezers based on where you put the liquid mix into the freezer: gravity-fed freezers have a reservoir up top, also known as a hopper, into which you pour the liquid soft serve or yogurt mix. Pressure-fed freezers, also known as pressurized CAB freezers, are distinguishable by having what resembles a bar fridge door at the bottom of the freezer behind which sit reservoir tubs that you pour the liquid mix into.
How the liquid mix gets to the freezing cylinder
In a gravity-fed freezer, what gets the liquid mix from the reservoir up top into the freezing cylinder is simply the force of gravity, allowing the mix to slowly seep into the freezing cylinder by way of the Mix inlet regulator, sometimes referred to as a carburetor.
In a pressurized CAB freezer, a pump forces the desired amount of air and mix from the reservoir bins in the bottom of the freezer into the freezing cylinder.
(Read more about peristaltic pumps vs. piston pumps)
Which type of mix delivery system—gravity-fed versus pressure-fed—will suit your needs depends largely on your application and store setting.
Self-serve or full-serve?
Will your frozen treats center be operated by your employees, or are you planning to have customers serve themselves? If you are planning a self-serve operation, your best bet is to use a gravity-fed freezer. Gravity-fed freezers are very straightforward, and more often than not, are equipped with self closing handles.
If your staff will be serving your customers, your needs (and profit margins) will be better served with a pressurized cab freezer. The main reason that pressurized freezers are not ideal in a self-serve setting is that the pump mechanism in a pressurized freezer can occasionally have pockets of air, which can result in a popping as the air is released from the cylinder when serving; this popping has the potential to soil the clothing of your customer, which I am certain you will agree, is less than optimal.
Which is easier to clean, a gravity-fed or a pressure-fed freezer?
Although both types of freezers usually have the same parts to clean associated with the freezing cylinder, pressurized freezers do have a few more parts to clean due to the pump mechanism which delivers the liquid mix. It is a given in the industry that a pressurized freezer will generally speaking take 15 to 20 minutes longer to clean than the 45 minutes to an hour it takes to clean and sanitize a gravity fed one.
This extra time is more than made up for however, by the simple fact that pressurized freezers only require to be cleaned and sanitized half as often as their gravity-fed equivalent.
In most areas, gravity-fed freezers need to be disassembled for cleaning and sanitation every fourth day. Pressurized freezers need to go through the same process weekly. You should check with your town or local Board of Health to see what cleaning regimen they require.
Can pressurized freezers save me time?
In any business, your greatest expenditure is the cost of labor. To pay an employee just under $10 an hour ends up costing you closer to $15 when all is said and done. You will save at least one hour of labor per week by using a pressurized freezer in your business instead of a gravity-fed one.
Last but not least: yield and profitability
If you were to set up two freezers side-by-side, with the only difference between them being that one was gravity fed, and the other pressurized, you would quickly realize that the pressurized freezer can yield 20% more servings from the same quantity of liquid mix poured into the freezer. It is essentially as though the dairy were providing you every fifth case of mix for free. In a pressurized freezer, one 5-gallon case of mix can yield on average 188 5-oz volume servings. At least $2.00 dollars net net profit per serving, this profitability difference adds up very quickly.
This distinction astounds most people who own another business; imagine a stand mixer in a pizza parlor that was able to yield 20% more dough from the same quantity of raw ingredients!
Cost of gravity freezer vs. pressurized
The cost difference of acquiring a pressurized freezer—over and above the cost of its gravity equivalent—can be quite steep. Some brands on the market charge as much as $8000 more for a pressurized freezer.
I am glad to tell you that the brand I favor doesn’t hold anyone for ransom! In fact, the cost differential between a gravity and its pressurized equivalent in my brand is limited to the selling price of the actual pump components, or just under $4000.
Read more tips & tricks
How to tell gravity-fed and pressure-fed freezers apart
In most cases, you can distinguish the two main types of freezers based on where you put the liquid mix into the freezer: gravity-fed freezers have a reservoir up top, also known as a hopper, into which you pour the liquid soft serve or yogurt mix. Pressure-fed freezers, also known as pressurized CAB freezers, are distinguishable by having what resembles a bar fridge door at the bottom of the freezer behind which sit reservoir tubs that you pour the liquid mix into.
How the liquid mix gets to the freezing cylinder
In a gravity-fed freezer, what gets the liquid mix from the reservoir up top into the freezing cylinder is simply the force of gravity, allowing the mix to slowly seep into the freezing cylinder by way of the Mix inlet regulator, sometimes referred to as a carburetor.
In a pressurized CAB freezer, a pump forces the desired amount of air and mix from the reservoir bins in the bottom of the freezer into the freezing cylinder.
(Read more about peristaltic pumps vs. piston pumps)
Which type of mix delivery system—gravity-fed versus pressure-fed—will suit your needs depends largely on your application and store setting.
Self-serve or full-serve?
Will your frozen treats center be operated by your employees, or are you planning to have customers serve themselves? If you are planning a self-serve operation, your best bet is to use a gravity-fed freezer. Gravity-fed freezers are very straightforward, and more often than not, are equipped with self closing handles.
If your staff will be serving your customers, your needs (and profit margins) will be better served with a pressurized cab freezer. The main reason that pressurized freezers are not ideal in a self-serve setting is that the pump mechanism in a pressurized freezer can occasionally have pockets of air, which can result in a popping as the air is released from the cylinder when serving; this popping has the potential to soil the clothing of your customer, which I am certain you will agree, is less than optimal.
Which is easier to clean, a gravity-fed or a pressure-fed freezer?
Although both types of freezers usually have the same parts to clean associated with the freezing cylinder, pressurized freezers do have a few more parts to clean due to the pump mechanism which delivers the liquid mix. It is a given in the industry that a pressurized freezer will generally speaking take 15 to 20 minutes longer to clean than the 45 minutes to an hour it takes to clean and sanitize a gravity fed one.
This extra time is more than made up for however, by the simple fact that pressurized freezers only require to be cleaned and sanitized half as often as their gravity-fed equivalent.
In most areas, gravity-fed freezers need to be disassembled for cleaning and sanitation every fourth day. Pressurized freezers need to go through the same process weekly. You should check with your town or local Board of Health to see what cleaning regimen they require.
Can pressurized freezers save me time?
In any business, your greatest expenditure is the cost of labor. To pay an employee just under $10 an hour ends up costing you closer to $15 when all is said and done. You will save at least one hour of labor per week by using a pressurized freezer in your business instead of a gravity-fed one.
Last but not least: yield and profitability
If you were to set up two freezers side-by-side, with the only difference between them being that one was gravity fed, and the other pressurized, you would quickly realize that the pressurized freezer can yield 20% more servings from the same quantity of liquid mix poured into the freezer. It is essentially as though the dairy were providing you every fifth case of mix for free. In a pressurized freezer, one 5-gallon case of mix can yield on average 188 5-oz volume servings. At least $2.00 dollars net net profit per serving, this profitability difference adds up very quickly.
This distinction astounds most people who own another business; imagine a stand mixer in a pizza parlor that was able to yield 20% more dough from the same quantity of raw ingredients!
Cost of gravity freezer vs. pressurized
The cost difference of acquiring a pressurized freezer—over and above the cost of its gravity equivalent—can be quite steep. Some brands on the market charge as much as $8000 more for a pressurized freezer.
I am glad to tell you that the brand I favor doesn’t hold anyone for ransom! In fact, the cost differential between a gravity and its pressurized equivalent in my brand is limited to the selling price of the actual pump components, or just under $4000.
Read more tips & tricks