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Why do we salt the ice when making ice cream?

timothyrice.org

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Re: Why do we salt the ice when making ice cream?

#51

Post by topaz0 »

iamkroot wrote: post #38
Taniwha wrote: post #27

Surely part of the issue is that the ice at If you add ice you reduce the equilibrium temp and as a result the < 0C ice temp can be passed to the liquid phase and as a result on to the inner con tain er where you're making the ice cream

The ice actually comes up to the temperature of the water while it's melting. That's what the equilibrium temperature is: the temperature of the entire ice / water system until it's been converted to all liquid or all solid. Naturally there's some small local variations, but if you let the system come up to steady state, that's what will occur.

To be fair to GP, it does take some energy to heat the ice from freezer temp to 0C (or the new, depressed freezing point), part of which will come out of the ice cream. It's just that that amount of energy is very small compared to the other energies we're interested in here (as you pointed out elsewhere).

Re: Why do we salt the ice when making ice cream?

#52

Post by bobthepanda »

foobarian wrote: post #37
floren wrote: post #35

Earlier quoted context omitted.

Salt's way cheaper than antifreeze, and I'd be a lot happier about getting a little stray salt in my ice cream than getting a little stray ethylene glycol (with bittering agents, since 2010).

I suppose I could store the salt water solution instead of throwing it away. Assuming I made ice cream often this would be acceptably frugal for me.

Also, if you really want to recover the salt, you’d just have to boil away the water.

Alternatively, pickling is a perfectly good use of brine used for frugal purposes (extending the shelf life of produce, eggs, and what have you)

Re: Why do we salt the ice when making ice cream?

#54

Post by OJFord »

distortedsignal wrote: post #49
OJFord wrote: post #43

Alternatively (edit - in the product itself): because it's delicious. If you like 'salted caramel' ice cream, try sprinkling some salt on vanilla ice cream. (I bet you'll find it's the 'salted' you like more than the 'caramel'.)

The article is specifically talking about salting the ice in a homemade ice cream maker like this[0]. The ice is used to reduce the temperature of the milk/sugar/etc. to "freeze" the ice cream. None of this salt gets into the ice cream. I agree with you - people should try salting their ice cream. But the article is about a different part of the ice cream making process. [0] https://www.amazon.com/Nostalgia-WICM4L-El…

Yes, that's why I said 'alternatively'. I anticipated something more along the lines of reasons for salt in the product going in. TFA was much more interesting, frankly, just thought I'd offer the other use in comments.

Re: Why do we salt the ice when making ice cream?

#55

Post by OJFord »

dmd wrote: post #47
OJFord wrote: post #43

Alternatively (edit - in the product itself): because it's delicious. If you like 'salted caramel' ice cream, try sprinkling some salt on vanilla ice cream. (I bet you'll find it's the 'salted' you like more than the 'caramel'.)

The salt being discussed here does not end up in the ice cream.

No, but 'alternative' uses of salt can.

Re: Why do we salt the ice when making ice cream?

#56

Post by OJFord »

ndiddy wrote: post #45
OJFord wrote: post #43

Alternatively (edit - in the product itself): because it's delicious. If you like 'salted caramel' ice cream, try sprinkling some salt on vanilla ice cream. (I bet you'll find it's the 'salted' you like more than the 'caramel'.)

Do you happen to know if MSG also works? I’m a big MSG fan, I would try this myself but I don’t have any vanilla ice cream at the moment

No, sorry, I've never used it (as an artificial/extracted additive I mean) - not opposed to it, I'm curious to experiment with it vs. 'natural'/more traditional ingredient sources.

I've seen ice cream served with parmesan crisp though, which is probably fairly salty too, but that's close.

Re: Why do we salt the ice when making ice cream?

#57

Post by rootw0rm »

ortusdux wrote: post #26

Testing for melting point depression is a common diagnostic method used in chemistry to check for impurities. Pure compounds melt at known temperatures, and typically do so within a narrow range (+/- 0.5 °C). Impurities almost always lower the melting point and widen this band. I spent a lot of my undergrad chem courses packing my products into capillary sized test-tubes and watching them slowly melt. https://www.mt.…

that's funny, i literally just grabbed a melting point apparatus out of storage to get rid of, because I have too much stuff laying around I probably won't use again

Re: Why do we salt the ice when making ice cream?

#58

Post by aaron695 »

timrice wrote: post #40
foobarian wrote: post #33

Earlier quoted context omitted.

This was a bit hard to spot in the writeup, as I have no clue about how ice cream making and machines work. Otherwise we could just use ice, which will be as cold as the refrigerator can get it. (I doubt the endothermic reaction of dissolving the salt contributes very much to the cooling). Now that I think about it, if I were doing this I would use antifreeze for the coolant instead of wasting salt. Bonus, I can stor…

Author here Surface contact is one reason you want an ice/water slurry instead of just ice, but the real reason is that ice melting consume a lot more energy than just ice being warmed up to it's melting point. The ice will quickly come up to it's melting (equilibrium!) point, without cooling the ice cream mixture very much. Remember, we're trying to freeze the ice cream (not just cool it down), which is proportional…

No post body was provided.

Re: Why do we salt the ice when making ice cream?

#60

Post by martyvis »

floren wrote: post #35
foobarian wrote: post #33

Earlier quoted context omitted.

This was a bit hard to spot in the writeup, as I have no clue about how ice cream making and machines work. Otherwise we could just use ice, which will be as cold as the refrigerator can get it. (I doubt the endothermic reaction of dissolving the salt contributes very much to the cooling). Now that I think about it, if I were doing this I would use antifreeze for the coolant instead of wasting salt. Bonus, I can stor…

Salt's way cheaper than antifreeze, and I'd be a lot happier about getting a little stray salt in my ice cream than getting a little stray ethylene glycol (with bittering agents, since 2010).

What's in the blue liquid in those ice cream making bowls that is normally sealed but sometimes people report it leaking. The manufacturers say it is nontoxic.
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