How A Slush Machine Works

the slush machine it produces a mixture

of water sugar flavor and coloring best

known by its name

slush always served at its ideal

temperature minus 3 degrees Celsius a

temperature that's impossible

below zero water freezes we should end

up with a giant coloured ice cube

floating in a cup not minuscule icicles

floating in coloured liquid but in the

name of refreshment the innocent slush

machine is transformed into a machine

that shatters the laws of physics

there's nothing easier than making slush

a little liquid concentrate made of

water sugar flavor and coloring pour the

liquid into the bowl add water

activate the mixers by pushing the

button a cooling system cools two hours

later the slush is good to go

in reality making slush is far from easy

because at the temperature it served

water freezes in order to reveal its

secret we need to take it apart


the cooling system keeps refrigerant

circulating through its pipes thanks to

a compressor a condenser expansion

valves and an evaporator in the

evaporators pipes the refrigerant

changes from liquid to gas the

transformation causes it to absorb lots

of heat by absorbing heat cold is left

behind the bottom of the ball which is

in constant contact with the cooling

system is extremely cold it's so called

it absorbs the heat in the solution and

calls it 2-3 degrees Celsius but below

zero water molecules in the solution

should change the solid form they should

cluster together to form ice crystals

two things prevent that from happening

one is the antifreeze in the solution

and the other is the continuous movement

of the mixers first on the antifreeze

it's the second most important

ingredient in the mixture it's no more

complicated or mysterious than good

old-fashioned sugar the sugar molecules

slip between the water molecules

preventing them from bonding to each

other since they cannot make contact

they cannot crystallize to form ice the

trick is to choose just the right

percentage of sugar to allow some of the

water molecules to touch each other

because after all we want some ice

crystals floating in the slush more than

22 percent sugar and its spoil we end up

with cold sweet liquid under 12 percent

sugar and it spoiled again too many

water molecules bond to each other the

mixture starts to freeze and the mixer

motors are damaged

now the mixers the other part of the

machine helping shatter the laws of

physics the horizontal mixer moves the

slush back to front the vertical mixer

moves the slush top to bottom

each mixer turns thanks to an electric

motor connected to a system of gears the

constant motion of the mixer prevents

freezing by constantly changing the part

of the mixture in contact with the

freezing-cold bottom the slush is

chilled evenly but most important the

movement also prevents water molecules

from bonding to each other which is

necessary to form ice the mixing motion

takes the few ice crystals that do form

and spreads them around otherwise ice

crystals would start collecting in the

top part of the machine since ice always

floats in water without the mixers ice

would float up to the top in reality

the machine has been perfectly designed

to allow such an improbable mixture to

exist it shatters the laws of physics

with two mixers and a little bit of


an ordinary accomplishment for a machine

that's anything but ordinary

by preventing water from forming the

bonds it needs to create ice the slush

machine keeps water liquid but below

freezing point