Instructables

How do soft-serve icecream machines work?

Hi, Does anyone know how softserve icecream machines work? I have a rough idea that they use an aerator but thats all.

Sparkington5 years ago
They use a powered mix. You add water to this mix then the machine does the rest. The mix has to be simultaneously frozen and whipped.

The mix has to be simultaneously frozen and whipped. In a factory, this happens in a giant tube surrounded by pipes. The pipes contain chemicals such as ammonia that freeze the tube, but the ammonia never comes into contact with the ice cream. The ice cream mix is pumped through the tube, where it gets cold very quickly. A dasher, or blade, turns inside the tube. This whips the mixture, introducing the air bubbles that help give ice cream its structure. The dasher also scrapes the sides of the tube, clearing off ice crystals that form there. This prevents large ice crystals from ruining the flavor and texture of the ice cream. All the elements of this process are carefully monitored and controlled by computers. Most homemade ice cream shops use a batch freezer for this step, where the same process happens on a smaller scale.

Got that info from HowStuffWorks
thermoelectric (author)  Sparkington5 years ago
Oh, Cool. So they don't use aerators?
Soft serve icecream is under immense pressure inside the machine. The inside of the 'tube' mentioned above is like a meat-grinder, where the auger moves the contents around, and helps force it toward the nozzle. You can hear gas 'pop' sometimes when large air bubbles get introduced into the mixture. While vending, the machine will make a loud popping sound, and spew small amount of frozen goodness all over the place :D As for powdered soft-serve, thats nasty. Reputable places usually use a real-milk product, (ice-milk or cream) although its not unheard of to use a non-dairy edible-oil substitude (same stuff as cool-whip).
thermoelectric (author)  frollard5 years ago
Oh, So the immense pressure introduces the air bubbles, Cool.
To elaborate, the 'edible oil product' is injected with high pressure gas, so when the pressure is released, it forms miniscule gas pockets that lighten and fluff the mix. Regular soft-serve just has the crap kicked out of it to break down the ice particles to 'nothing' size. You can tell it's the cheap mix when you can feel the abrasiveness of the ice crystals - thats the powdered crap.
BubbaOkie5 years ago
During the process, air is mixed into the mixture creating "overrun"-typically about 200% overrun, if I remember correctly. this would be 1 pint of mix becoming 3 pints of finished product.
thermoelectric (author)  BubbaOkie5 years ago
Oh, Wow. Is there really that much air in a soft serve??
Again, you must compare 'frozen soft serve' with 'soft serve ice cream' soft serve 'product' can be anything frozen, and soft. The edible oil product stuff IS whipped up with lots of extra gas to make it lighter. Real ice milk or ice cream soft serve is just pumped out under immense pressure to keep it soft and flowing. - Think a sorbet machine, like they use on iron chef.