Thanks so much Battle Gnome! Here's the recipe we used, which we followed exactly:
8 oz. of baking soda
4 oz. of citric acid
4 oz. of corn starch
4 oz. of Epsom salts
¾ tsp. of water
2 tsp. essential oil (we used essence of Orange, which was only a mid-range oil.. we didn't have best quality essential oil to hand for it - still, it smelled PERFECT in the first bomb!)
1 tsp coconut oil
A few drops of food coloring
Also, we live in Brisbane (Australia) where it's currently winter - so rain or humidity or heat haven't been a factor.
Hi there, welcome. Here is just my 2 cents, I apologize in advance for the length of the text : )
1) I would not dry bathbombs in the freezer, they need to have free flow of air to let moisture escape quickly. In the freezer the moisture will capsulate into small droplets, and when you take them out the droplets will thaw and set off the fizzingreaction. You may not even see it right away, or at all, but when you want to use them they will not be very reactive.
So best to let the dry on a table in a dry space ( I use a muffin tin to dry mine in. I drape a towel over the trey and place the bathbombs in each cavity so they get a softer "bed" to lay on)
You used the first one right out of the freezer, right? Then it was so fresh that all the fizzing hadn`t gone out of it yet. The others that weren`t in the freezer was unreactive, and it will be just a guessing game as to why. But, one important thing to remember when making these, is that
after adding water and oils to the mix, and working everything together, make sure the water - even though the ammount may seem TINY, is to not let any droplets be free, not mixed in properly.
This isn`t actually something you can spot easily either, so working the powder
really well after adding all ingredients will have a huge impact on the end result. When you feel it
is well mixed; mix it some more! Take powder between your hand, and press your hands together as you rub and squish the mix, forcing it to disperse the liquid that is in there.
PS! Make smaller batches at a time is sometimes helpfull, then you don`t waste a lot of ingredients if it doesn`t work.
2) You don`t actually have to use epsom salt! I leave it out sometimes. It can complicate things in a recipe, because will pull moisture out of the air and can give issues, even if you live in Australia and it doesn`t rain. Salt is salt. The weather fluctuates, even in winter, which can affect things. In my personal experience I really feel that this is also one of the things that makes one batch go perfectly one day, and not the next.
Besidedes, in the beginning of learning this process and what`s working and what`s not, it could be good to just keep things as
simple as possible untill you get a feel for things. You can actually make bathbombs without a lot of fillers.
Like 2 parts baking soda, 1 part citric acid, and a teaspoon of cornstarch. Then mix in the fragranceoil/essential oil into the oil you are using (coconut may work just fine, but another oil may be a lighter choice, but it is all up to what you have and what you feel works for you.
Spray with a mix of water/alcohol, or just alcohol. I never use plain water in mine anymore, it makes my results way too variable, so now I spritz with rubbingalcohol and add my oils (sheabutter/cocoabutter) and fragrance/essential oils, and work everyting into a wet-sand paste. Working with smaller batches and working fast is my method of consistansy and success.
I got much more consistant results after skipping plain water, because the weather and humidity here in Norway is so random, that after switching to alcohol and oil, things became so much more easy and controllable.
3) I agreing with Dahila, too much cornstarch can make your bathbomb crumbly and not stick together, but you
can add some, as it makes the water feel nice and silky. I just use 1 teaspoon of it in my batch, and I can totally feel the difference with that small ammount. Kaolin clay works really well too, makes the bathbombs rock hard. I use 1 teaspoon in my batch.
4) Re. Foodcoloring and being illegal. Don`t worry, it is not illegal to use foodcoloring in your
personal bathbombs or other cosmetic products. But not if you are planning to
sell them, then that is another story. Then you need the colors to follow strict cosmetic regulations.
But this was just for your
personal use, so if that is what you have on hand, no worries!
You may know this already, but in case not, just mentioning the staining issue when you use more. A few drops will not be a huge deal, but it can stick to the skin in higher doses.
Sorry if I repeated something someone else covered, sometimes people chimes in while I write, so things may be repeated : P
ETA, yup, sorry I didn`t see that BG had said some things I covered, sorry about that.