Issue with Soft Bath bombs

[tourist4ever]

Hi

I have been doing bath bomb experiments for a couple of months now and about over a month ago got the right consistency (or so i thought) and therefore submitted my recipes for cosmetic safety assessment. Since then i have been doing batches however now for some reason bombs are now soft, if you press enough they just crumble to bits.. this is days after drying. I use the same recipe as before and previous bombs i had were made more towards beginning of the year which makes me think could the humidity be the issue, i live in UK (humidity between 70-90%.

My recipe is below. my problem is as i have already paid for the safety assessment quite a bit i was hoping not to add/remove too many ingredients. I noticed there is a user on etsy selling their bath bombs and their ingredients are close to mine, the only difference is they are using coconut oil as well with almond oil and witch hazel in each bomb and do not have any salt in them and their bombs are rock hard. I would be hoping to be close to that as I have already purchased bulk ingedients and wouldnt want them going to waste or make a loss.. I dont mind adding the coconut oil and leaving epsom salt out if need be, i could probably try to resell it. I guess my question is does anyone know whether it would be possible to get workable bath bombs with the ingredients rather than purchasing more different ingredients? any input is appreciated as i'm a bit at a loss here.

200g bicarb
100g citric acid
100g corn starch
100g epsom salt
9g almond oil
5g poly 80
7-10g essential oil depending which one
if 7g then adding witch hazel 3g , if 10g then leaving it out

 

[marlajune]

Too much corn starch and Epsom salt. You need to lower the percentage to 10%. It's very humid here. I use soda 60%,citric acid30%, 5%goat milk powder & 5% arrowroot. My bombs are hard and sturdy despite the humidity.

 

[lsg]

I use melted cocoa butter in my bath bombs and they get very hard.

https://www.soapmakingforum.com/threads/help-with-bath-bombs-please.82580/#post-870180

 

[BWt]

Cream of tartar will help harden and keep bath bombs hard. Here is a great recipe. The witch hazel and dye is mixed into the baking soda and salt. Then the citric acid and cream of tartar mixed in. Then Poly 80, fragrance, and oil. The citric acid does not react with moisture when using this method. Humidity is ideal at 40%. I put newly made bombs in a room with dehumidifier. This recipe uses a press but I make same recipe using metal hand held spheres and it works perfectly. Sometimes I add Bioterge 90 powder to the mix. Winter Solstice Bath Bombs - Humblebee & Me

 

[Dwilson9]

I use melted cocoa butter in my bath bombs and they get very hard.

https://www.soapmakingforum.com/threads/help-with-bath-bombs-please.82580/#post-870180

Refined? Unrefined? Deodorised?

 

[BWt]

Refined? Unrefined? Deodorised?

Cocoa butter scent is absolutely a chocolate scent. Unrefined smells like chocolate. Refined has virtually no scent. I use unrefined because I found a very good price for 5 lbs. food grade but was opened at customs for inspection. being sold as cosmetic grade. $24 for five lbs. shipping reasonable Cacao Butter for Cosmetics / Candles / Soap

 

[AliOop]

Refined? Unrefined? Deodorised?

Whichever you prefer. As @bwtapestry stated, unrefined has a chocolate scent, so be sure that goes with any other scent you may add.

 

[BWt]

Refined? Unrefined? Deodorised?

Any type. Depends on how you want to add scent. Currently am not using cocoa butter. Only liquid oils. Leaving out all salt as it attracts moisture to the bombs.

 

[BWt]

Whichever you prefer. As @bwtapestry stated, unrefined has a chocolate scent, so be sure that goes with any other scent you may add.

@Dwilson9 There is an excellent book by Robyn French Smith. Bath Bomb Revolution. It has a very good basic bath bomb recipe plus another 4 recipes for bombs. I add cream of tarter to the basic recipe in this book as I find it hardens bombs. Also I learned from SoapandClay YouTube video (@AliOop recomended) that removing a tiny bit of oil and adding that back as water helps harden bombs. DO NOT add salt if you are working in a humid environment. Salt is hygroscopic and will draw moisture into itself. Salt isn’t required for a good bath bomb. If a client wants salt advise them to add it separately after the bomb has dissolved. Most importantly add the citric acid at the very end after every other ingredient has been added. That way the citric acid will not react by fizzing. The other ingredients are bound together with thorough mixing and the citric acid blends beautifully in.