How to Make Slush Mix for Slush Machines

How to Make Slush Mix for Slush Machines

Businesses thrive on uniqueness. If your business can offer one-of-a-kind deliciousness, you can encourage repeat customers and grow your business through enticing marketing. One way foodservice establishments attempt to grab these benefits is through customized, house-made menu items, but not many operators know off-hand how to make slushie mix. The process is tricky in a few ways, as too much or too little sugar can prevent the slush from freezing or make it freeze too easily and destroy your drink machine.

Operators have two choices when creating unique slushies: mix two or more flavor syrups together or attempt to make their own slushie syrup with sugar, water, and flavorings.1 If you want to develop your own recipes for frozen drink machines, you're going to have to learn about Brix and how to use a refractometer.

How to Make Slushie Mix: Table of Contents

How Slushie Mix Works

Every operator with a frozen drink machine can offer the basics; if you want to stand out from the crowd, you can go a step above by crafting your own flavor combinations. We carry a range of interesting slushie syrups that come with precise instructions for achieving the right concentration of sugars to produce a delicious final product. However, attempting to combine different flavors and different brands of slushie mix can be tricky, as the syrups might have different sugar concentrations.

Sugar interferes with the freezing process of water. Colder temperatures are required to freeze sugar-water than pure water, so your frozen drink machine will be working at temperatures lower than 32 degrees Fahrenheit. If your slushie mix does not have enough sugar, it can freeze solid rather than turning into the desired slush, which can cause your machine to be rendered completely inoperable, as has happened to 7-11 in the past.2

If you're making your own slush mix without any pre-made syrups, you'll need to be even more careful about the sugar concentration. Operators must get the balance of sugar to water correct, or the mix either won't freeze or will freeze too hard and potentially damage the machine. To find the right balance of mixture to water, you'll need to understand the Brix scale.

Understanding the Brix Scale

Brix is a unit of measurement for the sugar content of a liquid solution, with 1 degree Brix equaling 1 gram of sugar in 100 grams of water.3 Brix is measured with a refractometer, which uses how light refracts through the liquid to determine the volume of dissolved solids, specifically sugar, within it. A Brix measurement between 13 and 15 Brix is considered the ideal range, though some mixtures as low as 11 or as high as 18 can work.

Water freezes at 32 degrees Fahrenheit, forming ice crystals that eventually solidify into ice. Sugar particles suspended in the water make that freezing process more difficult by physically hindering those ice crystals from bonding with each other. When more sugar is present in the mix, the formation of ice in the liquid is inhibited, meaning it must be colder before it'll freeze. This is especially true in a frozen drink machine that keeps the mixture moving. Not checking the Brix measurements on your slushie mixes can lead to a solid block of ice and burned-out slushie machine. On the flip side, a Brix measurement that's too high will prevent your drink from freezing into the slushy texture that customers crave.

How to Use a Refractometer

To measure Brix, you'll need a refractometer. If you've ever looked at a straw in a glass of water, you've probably noticed how it looks bent as it meets the liquid. This effect is caused by refraction, or light bending as it moves through different mediums, whether those mediums are solid, liquid, or gas. Because light moves differently through water than air, it gives the straw a bent appearance. Refractometers use prisms to measure how light moves through liquids to determine how much sugar is dissolved in the mix.

Most refractometers work by placing a well-mixed sample of the test liquid into the refractometer, then looking into an eyepiece. Light will refract through the liquid and create a line inside the refractometer that denotes where your solution falls on the Brix scale.

  • To raise the Brix, add more sugar to the solution
  • To lower the Brix, add more water to the solution
  • Be sure to mix thoroughly after adding sugar or water

How to Make Slush Mix for Slush Machines

If you want to completely abstain from utilizing premade slushie syrups, you can make your own with simple syrup4 and flavorings. Make a syrup from sugar, water, and flavorings, then dilute that concentrated syrup with more water until you get the right concentration. Premade slush syrup will direct you to mix it with water, usually in a four or five to one ratio, so if you mimic this concentration you should end up in the right Brix range, which you can then adjust using your refractometer.

Once you learn to combine sugar, water, and unique flavorings to create a perfect slushie mix, you'll open up an unlimited number of potential menu items. These can be easy to make, inexpensive, and infinitely customizable, so you can discern which recipes drive the best business.

  1. How to Use a Slushie Machine. Jeffrey Morgenthaler. Accessed October 2021.
  2. Cola Wars Take a Cold, Slushy Turn. The New York Times. Accessed October 2021.
  3. What Does Brix Mean?. IRMCO. Accessed October 2021.
  4. Simple Syrup. AllRecipes. Accessed October 2021.