Using saltpetre for cooling drinks (2013)

Re:Using saltpetre for cooling drinks (2013) by nibbleshifter on Sunday August 28, 2022 @02:08PM (#32630526)

I'd love to try this myself, but where I currently live - despite being an ingredient in a few traditional cured meat dishes - nitrate salts require a virtually unobtainable (to a private person) permit to obtain, because of terrorism concerns.

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Re:Using saltpetre for cooling drinks (2013) by masklinn on Sunday August 28, 2022 @03:32PM (#32631303)

FWIW the dissolution of table salt in water is also endothermic, though to a much lower extent than saltpeter: the enthalpy of solution for saltpeter is +34.9kJ/mol, for table salt it's +3.87.

An other option is ammonium nitrate at +25.69, though you might also have trouble with terrorism regulations as it's both a common fertiliser and a component for explosives.

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Re:Using saltpetre for cooling drinks (2013) by nibbleshifter on Sunday August 28, 2022 @06:19PM (#32632624)

I often will use salt in ice baths specifically for that reason :)

Ammonium nitrate used to be uses in the "instant ice/cold packs" for first aid, but has since been replaced with urea - I believe due to the terrorism regulations.

Which means (as another poster suggested) I'll be trying urea as a way to chill drinks sometime soon I guess.

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Re:Using saltpetre for cooling drinks (2013) by hoseja on Monday August 29, 2022 @06:19AM (#32636485)

I think the reason for saline cooling baths is that the liquid stays liquid at lower temperature, not any additional cooling from dissolving the salt.

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Re:Using saltpetre for cooling drinks (2013) by jsjohnst on Sunday August 28, 2022 @02:18PM (#32630614)

> where I currently live

Not surprised by your story, but still curious where you live? In the US, you can buy it in bulk quantity on Amazon. Mixing it with sugar was a ton of fun when I was a kid, smoke bombs that could totally white out a large backyard.

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Re:Using saltpetre for cooling drinks (2013) by nibbleshifter on Sunday August 28, 2022 @02:46PM (#32630872)

A Western European country.

I could easily order it from overseas online, but the consequences are pretty harsh (violates the explosives laws). Not worth it tbh.

Somewhere else I lived in Eastern Europe, it was available in shops in 100g bags for curing meat, etc, or at the garden shop in 25kg sacks as a fertiliser.

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Re:Using saltpetre for cooling drinks (2013) by UpstandingUser on Sunday August 28, 2022 @02:29PM (#32630713)

You can get it at the hardware store, it'll break down tree stumps pretty quickly (and very inexpensively).

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Re:Using saltpetre for cooling drinks (2013) by jsjohnst on Sunday August 28, 2022 @02:34PM (#32630764)

Yep, any place that has garden supplies generally has it. That’s where I got it when I was a kid anyway, as that was years before Amazon’s existence.

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Re:Using saltpetre for cooling drinks (2013) by PBnFlash on Sunday August 28, 2022 @03:28PM (#32631267)

Urea also is endothermic, and as it is used in diesel engines I am quite sure it's available globally.

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Re:Using saltpetre for cooling drinks (2013) by nibbleshifter on Sunday August 28, 2022 @05:14PM (#32632122)

Aye, urea is what's in the "instant ice packs" now.

It used to be ammonium nitrate, but most brands switched it to urea a few years ago - presumably for reasons of "people could use the extremely nice, uncoated, very pure ammonium nitrate for nefarious purposes" (useful for explosives and methamphetamine manufacturing!)

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