Question re bath bombs

[AndyRoo]

Hello all,

I hope everyone is well. I was just wondering if anyone might have any insight in to this: I finally perfected my bath bomb recipe (or so I thought, recipe below), however, I recently had an issue whereby one of the bath bombs I had made and was drying suddenly expanded slightly and then came apart as if it had both expanded and then rapidly dried at once and became powdery. I have a theory (also below), but I wanted to know if anyone else might have any ideas.

The recipe I use is:

1/2 cup cornflour
1/2 cup baking soda
1/2 cup citric acid
1/4 cup Epsom salts
2 tablespoons of liquid glycerine
2 teaspoons of almond oil
few drops colouring (not water based)
few drops (half to whole teaspoon, depending on how strong the scent is) - PureScented brand, supposedly 100% oil based.

I stopped using water in my recipe because every single time, without fail, there was a reaction and the bombs never set.

What happened in this latest instance was that I had made some bath bombs which had been drying out for a few days - which were fine - and then I made some new bombs which were slightly more wet than usual and (probably stupidly) set them aside in the same box I use to dry them out. My theory is that the moisture somehow activated the other bombs and caused them to expand.

The area in which they were left wasn't humid or anything like that... but I can't figure out how they appeared to have both expanded, and then dried out and become powdery at the same time!

Any other theories?

Cheers,
Andy

 

[shunt2011]

Not enough baking soda, adding glycerin are two issues. Glycerin will attract moisture. I use 91% rubbing alcohol not water.

 

[AndyRoo]

Not enough baking soda, adding glycerin are two issues. Glycerin will attract moisture. I use 91% rubbing alcohol not water.

Out of curiosity, why do you say not enough baking soda? They fizz perfectly well.

 

[shunt2011]

Because most successful recipes have twice the amount of BS than CA. If it works for you that’s fine though.

 

[AndyRoo]

Because most successful recipes have twice the amount of BS than CA. If it works for you that’s fine though.

Oh, I thought maybe there was something about the chemical reaction that I was missing. They don't go crazy, but they fizz a decent amount.

I'm reluctant to start putting anything water based (including alcohol) back in to the mix as it's been a disaster every time. A mate who makes them for craft fairs said she never puts anything but oil/glycerine in hers, so I thought I'd try the same. It's just so odd, they were absolutely perfect and then after 3-4 days of drying, they just suddenly lost their cohesion! :/

 

[shunt2011]

Glycerin attracts moisture. I generally only use cocoa butter in mine but will use alcohol if it needs a bit more moisture. Never causes an issue

 

[Kamahido]

Have you considered using Witch Hazel as a liquid? It will not start the chemical reaction.

 

[AndyRoo]

Glycerin attracts moisture. I generally only use cocoa butter in mine but will use alcohol if it needs a bit more moisture. Never causes an issue

I think I am going to try a batch tonight using just vitamin e and sweet almond oil. I don't think either of those are humectants?

 

[Terri E]

I would try 1/4 C cornstarch, 3/4 C baking soda, 1tsp turkey red castor, shea or cocoa in place of glycerin and a 50/50 mixture of witch hazel/alcohol for just a little spritz to help it hold together if needed. I mist mine lightly after they are set up to dry

 

[AndyRoo]

I would try 1/4 C cornstarch, 3/4 C baking soda, 1tsp turkey red castor, shea or cocoa in place of glycerin and a 50/50 mixture of witch hazel/alcohol for just a little spritz to help it hold together if needed. I mist mine lightly after they are set up to dry

Thanks, I might have a try with that one. The only thing that puts me off is witch hazel - I can't stand the smell of the stuff... unless it comes in odourless form these days?


I've just tried a slightly altered recipe in which I have replaced 1 tablespoon of glycerine for 2 teaspoons of almond oil. Seeing how that works out.

I've also bought some coconut oil to see how that compares. I will get these right eventually, it's just a costly process which is infuriating! :/

My bath melts, bath jellies, and soaps have all been really good, but I am beginning to think my bath bombs are cursed!! lol

 

[Loralei]

I use witch hazel as well, and add in very small amounts, to avoid any reaction..

I am curious to see cocoa butter used - I've never thought of that (total newbie at making bath fizzies)!