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Old 02-09-2020, 07:44 PM
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Circulating juice machines


You know those juice fountain machines you might see in convenience stores, gas station stores, diners, etc., that appear to be constantly circulating the juice?

Is there a practical reason for the juice to circulate like that, or is it just about presentation?
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Old 02-09-2020, 08:16 PM
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Well, it keeps any pulp from settling.
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Old 02-09-2020, 08:45 PM
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Except that there's usually no chance of pulp, because they're not "juice" at all, just sugar-water.

I suppose that if they're saturated enough, they might be worried about sugar precipitating out.
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Old 02-09-2020, 09:18 PM
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I always thought it was because they used powdered drink mixes, and didn't want to risk sedimentation.
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Old 02-09-2020, 11:04 PM
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I decided to go straight to the source, and took a look at the spec sheets for a couple of units from the manufacturers of the devices. The spraying and stirring is to keep the juice evenly stirred so that it is all of a uniform consistency and temperature. The ones that I looked at all have an optional rotating insert that can be used to stir liquids that are not suitable for spraying.

The spraying also serves an advertising purpose. "Visual display creates impulse sales" as one manufacturer describes it.
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Old 02-10-2020, 09:28 AM
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I have seen artificial fruit juices (the kind usually sold in these machines) in stores in clear bottles. I haven’t seen any settling in those bottles and I am highly doubtful that the slow speed, that they operate, will be effective in settling prevention. The temperature uniformity aspect, I believe that. But I think it’s mostly a gimmick.
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Old 02-10-2020, 10:45 AM
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It also allows the juice to be circulated over cooling coils and be kept quite cold ( and not frozen ) all throughout the volume.

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Old 02-10-2020, 03:20 PM
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I don't see the machines often any more, but back in the day when I did see the machines, it was usually dispensing a semi-frozen slurry of some "fruit" juice. I assumed the constant stirring was to keep the slurry from freezing solid.
Obviously not applicable to fluids not near their freezing point.
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Old 02-10-2020, 07:51 PM
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Years ago, I worked at a corporate coffee chain. No, not that one. But we had the circulating machine for some dairy-based coffee/sugar drinks. We'd have to tear it all down and clean it a few times a week. The bowl would get really nasty since the churning would cause the formation of little drops of basically butter which would stick to the transparent acrylic surface of the bowl. The circulation portion was a type of mag-stirrer.

Quote:
Originally Posted by rbroome View Post
I don't see the machines often any more, but back in the day when I did see the machines, it was usually dispensing a semi-frozen slurry of some "fruit" juice. I assumed the constant stirring was to keep the slurry from freezing solid.
Obviously not applicable to fluids not near their freezing point.
Those granita machines are different from what's described in the OP. They use a very simple but interesting mechanical torque based switching control system. The mixture freezes as the motor turns. Eventually, the torque is such that the entire bowl begins to rotate a few degrees which toggles a microswitch and disengages the cooling. They were a maintenance headache since they had to be cleaned and sanitized often and were touchy when being reassembled after.
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Old 02-10-2020, 07:59 PM
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Forgot to add the links!

Granita:
https://vollrath.com/vollrathUnivers...peration-Video

Crathco:
https://www.youtube.com/watch?v=BubUvWWF57c
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