Picture a gadget which looks like a cake mixer, but while it mixes the milky contents of a bowl, it's also injecting in Liquid Nitrogen to turn it all into Ice Cream.
You fill up a bowl with milk and other stuff like syrup, chocolate chips, etc. Then switch on this mixer machine to mix the contents in the bowl, and when you push a button, a stream of ultra-cold liquid nitrogen flows down through the mixer attachment into the milk mixture, freezing it instantly into ice cream. That instant flash-freezing means the ice crystals are all small, giving the ice cream a perfect texture.
The device would be powered from a wall outlet, and would have an ammonia coil refrigeration unit built in that charges up a small canister to fill it with liquid nitrogen. Once the canister is charged, an indicator light will show that the unit is ready to be used. When the canister is depleted, the unit must be set to charge it up again using its refrigeration unit.
UPDATE: Now that I think about it, maybe it would work better in a blender type of configuration. Just drop your fruits like bananas, berries, chocolate chips, etc into the blender, and then pour milk in to top it up. Then turn on the machine and it blends everything, then towards the end of the blending cycle it bubbles in the Liquid Nitrogen from the bottom to thicken and solidify the mixture into perfect ice cream. In a half-way partial intermediate mode/cycle, it could make milk-shakes instead of ice cream.-- sanman, Dec 26 2013 Cake Mixers http://www.amazon.c...%2Ck%3Acake%20mixerVarious Cake Mixers from Amazon.Com [sanman, Dec 26 2013] Home made liquid nitrogen generator http://citizenscien...nitrogen-generator/"The device that I built cost less than $500 and produces l liter of liquid nitrogen per day." [spidermother, Dec 27 2013] //The device would be powered from a wall outlet, and would have a compressor built in that charges up a small canister to fill it with liquid nitrogen.//
That won't work. You can't make liquid nitrogen simply by increasing the pressure.-- spidermother, Dec 26 2013 I know - but the compressor can drive refrigeration which can generate the liquid nitrogen.-- sanman, Dec 26 2013 Liquid nitrogen - bah. If you are going to do this, do it right with liquid helium. One could create the Einstein-Bose Condensate flavor. Now that will stick to your ribs - if it lets go of your tongue!-- bungston, Dec 26 2013 Well, since nitrogen can be pulled right out of our air and liquified, then it would be the best medium for storing cold and then giving a heaping dose of that cold to freeze milk into ice cream. I was also thinking that this approach might be good for flash-freezing other food. Like suppose you bring home some fish from the store, and want to preserve it without losing its texture. Maybe this approach to flash-freezing and resulting micro-crystallinity would be the best way to freeze items without damaging their original freshness and quality.-- sanman, Dec 26 2013 How do either devices described differ from the numerous liquid nitrogen ice cream makers of various design that already exist? I googled 'liquid nitrogen ice cream maker' and some of the top hits were machines that appear remarkably similar to this idea.-- Alterother, Dec 26 2013 [sanman] My point was that making liquid nitrogen (or even liquid air) is more difficult than you seem to think it is. The barrier to a domestic liquid nitrogen-making icecream maker is not that no-one thought of it, but that it would cost millions and be bigger than your house*.
Nitrous oxide might be better. It can be stored in liquid form at room temperature (like carbon dioxide).
*(Edit) OK, that's an exaggeration.
<Eats flash-frozen words> (Link).-- spidermother, Dec 27 2013 One liter of liquid nitrogen does not go very far. Without doing any of the math that I barely have a grip on, I'd be surprised if you could make a half that amount of ice cream with it.
I've seen plans for home gas condensers, and I've seen the big industrial models used at gas suppliers. They're huge, expensive, permanently-installed machines that go chugga- chugga-chugga at a volume I would not want in my garage. I'd think if the little homebuilt units I see in the online 'plans' worked as well as they claim, the supply companies would choose those over the big chugga chugga variety.-- Alterother, Dec 27 2013 Quite. I'm just surprised that it's (apparently) possible to make liquid nitrogen on such a small scale at all.
(By the way, frozen milk isn't, legally or morally, ice cream.)-- spidermother, Dec 27 2013 What about Supercritical CO2? I keep hearing lots of good things about it, and how it's an advanced refrigerant whose higher pressure cycle could allow for smaller hardware. Could that be a new way to push the envelope, including for making better ice cream?-- sanman, Dec 30 2013 I have doubts about the CO2. It makes an acidic sour twang note in carbonated beverages that doesn't seem like it would work well in ice cream.
(I've had carbonated milk. I liked it, but still don't think it would be right for ice cream. Sherbet, on the other hand... hmmmm...)-- lurch, Dec 30 2013 Baked... Alaska.-- UnaBubba, Jan 01 2014 random, halfbakery