Reverse Engineering Crackles

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Calling all chemists, alchemists, and sciencey folks! How hard can it be to make these bath crackles?! There are so few ingredients. I don’t mind buying them, but I’d love to be able to make then DIY! Are you familiar with this bathing wizardry? Any idea how to make them? I think the magic is probably in the carbon dioxide, but searching the interwebs has not turned up much.
 

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like pop rocks?

I recently read that the secret to pop rocks popping was in the manufacturing process. Compressed CO2 is injected in the sugar so when the sugar melts on your tongue the pressure shoots the candy around your mouth.

if that’s the case you’d probably need to get liquid CO2 and freeze it in drops. coat the drops in sugar before they melt. Room temperature storage would melt the CO2 ice but the candy shell keeps it from evaporating on the shelf.

maybe dry ice can give the same effect? Not too sure on how the construction of the actual product from there.
 
like pop rocks?

I recently read that the secret to pop rocks popping was in the manufacturing process. Compressed CO2 is injected in the sugar so when the sugar melts on your tongue the pressure shoots the candy around your mouth.

if that’s the case you’d probably need to get liquid CO2 and freeze it in drops. coat the drops in sugar before they melt. Room temperature storage would melt the CO2 ice but the candy shell keeps it from evaporating on the shelf.

maybe dry ice can give the same effect? Not too sure on how the construction of the actual product from there.

Liquid CO2 only exists under pressure. You can't freeze it into dry ice at home in a regular freezer. You need industrial equipment to do that because you have to be able to pressurize it.

Dry ice sublimes directly into a gas as it "melts" at normal atmospheric pressure at room temperature. As it does, it will build pressure inside of a sealed container, including a candy shell. At 1 ATM of pressure, only storage in a deep freezer below -109°F/-78°C will prevent it evaporating. A normal household freezer can only get as low as -20°F/-29°C. The CO2 in Pop Rocks candy is already a gas, not pieces of dry ice.

I suspect that these bath crackles (and probably Pop Rocks too) are made on very specialized industrial equipment that involves the ability to pressurize/depressurize a chamber where everything is mixed, so that the tiny bubbles of CO2 gas inside the mixture will be under slight pressure inside the cooled pieces when the chamber is depressurized back to 1 ATM. The mixture is basically sprayed to make small particles (still under pressure) and allowed to cool/dry/harden (still under pressure). Once cooled/dried, the chamber pressure is restored to ambient air pressure and the tiny bubbles of CO2 inside the pieces are still under pressure because the stuff around them has hardened. The pressure is released when the solid substance is dissolved away when it's used.

Basically, I don't think this is something that can be made at home. I'm sorry to disappoint. ☹
 
Agree.

Though a soda siphon could be used to inject the gas into a mix inside the siphon, I don't see how one would get the contents to dry inside it. Release the pressure... fizzing glop, I think.

Industrial vessels can manage humidity and temperature as well as pressure.
 
Though a soda siphon could be used to inject the gas into a mix inside the siphon, I don't see how one would get the contents to dry inside it. Release the pressure... fizzing glop, I think.
I thought the same thing. "Fizzing glop" is exactly what you'd get.
 
Liquid CO2 only exists under pressure. You can't freeze it into dry ice at home in a regular freezer. You need industrial equipment to do that because you have to be able to pressurize it.

Dry ice sublimes directly into a gas as it "melts" at normal atmospheric pressure at room temperature. As it does, it will build pressure inside of a sealed container, including a candy shell. At 1 ATM of pressure, only storage in a deep freezer below -109°F/-78°C will prevent it evaporating. A normal household freezer can only get as low as -20°F/-29°C. The CO2 in Pop Rocks candy is already a gas, not pieces of dry ice.

I suspect that these bath crackles (and probably Pop Rocks too) are made on very specialized industrial equipment that involves the ability to pressurize/depressurize a chamber where everything is mixed, so that the tiny bubbles of CO2 gas inside the mixture will be under slight pressure inside the cooled pieces when the chamber is depressurized back to 1 ATM. The mixture is basically sprayed to make small particles (still under pressure) and allowed to cool/dry/harden (still under pressure). Once cooled/dried, the chamber pressure is restored to ambient air pressure and the tiny bubbles of CO2 inside the pieces are still under pressure because the stuff around them has hardened. The pressure is released when the solid substance is dissolved away when it's used.

Basically, I don't think this is something that can be made at home. I'm sorry to disappoint. ☹
I have seen how-to’s for infusing fruit with co2 using a thermos and some dry ice. I assume this is similar, larger scale, and probably kind of what you’re talking about. And, you’re probably right.
 
I remember a while back that all of the big suppliers I use were advertising some sort of popping additive...I think made of coconut...or cocoa butter...coco something... are those still a thing? Maybe those would work if you could find them.

Edit: BB still has them
https://www.brambleberry.com/shop-b...s/V001259.html#q=popping&lang=default&start=1
That looks like an interesting option. Reviews are very polar! Seems like not a good idea to try and order them in the summer at least. Might be worth a try, but I think MrB may be cheaper, and won’t melt. I wonder how they did it though! Nothing in the ingredients has pop effect. It must be infused with co2.
  • Ingredients (Common Name): Sugar, Cocoa Butter, Lactose, Corn Syrup Solids
 
That looks like an interesting option. Reviews are very polar! Seems like not a good idea to try and order them in the summer at least. Might be worth a try, but I think MrB may be cheaper, and won’t melt. I wonder how they did it though! Nothing in the ingredients has pop effect. It must be infused with co2.
  • Ingredients (Common Name): Sugar, Cocoa Butter, Lactose, Corn Syrup Solids
Yeah, they have carbon dioxide in them...basically pop rocks but with cocoa butter.
 
Creating the CO₂ in situ from sodium bicarbonate and citric acid (like mini bath bombs) is no option? Do they need to be edible, or are you aiming on a non-food application?

I once looked up if dry ice is suitable to carbonate beverages. Short answer: no. Besides various risks from overpressure, low temperatures, etc., most technical qualities of dry ice contain residues of pressure pump lubricants, which anecdotally aren't exactly yummy.
 
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