What is forming on top of my soap?

[Delon]

Hi yall, I hope this is the correct place to post this! This is my second batch of soap, and I’m not really sure what’s forming on top of my soap. Almost looks like little crystals.

I put the soap in the freezer right after pouring since I’m using coconut milk in the recipe. Any ideas on what it could be? Btw, the bars had been out of the freezer for 24 hours when this picture was taken and the white stuff is still there. I haven’t tried to wipe it off just yet.

 

[Zing]

Can you please post your recipe including any additives and scents?
Your soap looks nice.

 

[AliOop]

Yes, please do as @Zing asked. Meanwhile, what the pictures appear to show is that your loaf overheated and separated, creating lye tunnels. Those "teeth" looking things are one of the signs of that. Is there any liquid below those spots, or are those just empty holes?

Until we know more, I'd wear gloves and be very careful while handling those bars.

 

[Delon]

Can you please post your recipe including any additives and scents?
Your soap looks nice.

Thank you!

Yes, please do as @Zing asked. Meanwhile, what the pictures appear to show is that your loaf overheated and separated, creating lye tunnels. Those "teeth" looking things are one of the signs of that. Is there any liquid below those spots, or are those just empty holes?

Until we know more, I'd wear gloves and be very careful while handling those bars.

@AliOop @Zing

This is only my second batch of soap, so I've already been told by people on Reddit how horrible I was to use lime juice. I won't use it again.

I used a 50/50 lye solution with iced lime juice. 5% super fat.

15% Coconut oil
5% castor oil
20% coconut milk
30% olive oil
15% shea butter
15% sunflower oil

I placed the soap in the freezer right after pouring, so I'm not sure how this overheated.

I unmolded the soap closer to 48 hours because the mold was too soft to unmold prior to that point. When I cut the soap, it was still pretty soft. I placed the cut bars on freezer paper and left them alone for another day and a half. I tried the zap test, got zapped, and left them alone for another day. On the 4th day, I did not get zapped. I tried the zap test on multiple bars and no zap.

I accidentally poured the titanium dioxide in without dispersing it in distilled water first, so there are small white dots. I looked it up, and people say it's fine to use and won't harm your skin. Also, the bars are completely dry, no extra oils in the holes. There aren't holes in all the bars, just a few (1-3).

I read on another post from a few years back that it could be bad soda ash because it wipes off with a damp paper towel.

I was able to try out the end piece a day after I did not get zapped since it was more sample-sized, and the lather was perfect. The bars have hardened, and the one I tried feels great on my skin.

I just don't know what that is on top, and I wasn't sure if anyone else has experienced this.

 

[akseattle]

@Delon, hmmm, I've never got little crystals like that, but I've gotten soda ash.
I actually thought that soda ash can form small crystals like that. But, again, I don't speak from experience.

 

[Ekuzo]

I regularly get soda ash, just not crystals like these - but I've seen people get all types of soda ash, so it won't surprise me if it's just that. Plus you said you get no zap and it gets easily removed.

Why is the coconut milk included within the oil % though, could it be that it messes up the math for you, and what calculator did you use? Also, why did you decide to have both lime juice and coconut milk for the liquid part?

When you made the 50% lye solution with the lime juice, did you notice any sediment or undissolved stuff in it, and did you strain it when you poured it into the oils?

Sorry for all the questions, I'm just trying to figure out what's happening with the recipe, it has so much going on.

There are a least of couple of things that are usually not done with your second batch, but when you gain more experience with soap. Like mixing different alternative liquids or dissolving lye in the same amount of liquid (for example, if you don't measure correctly you can have undissolved lye in your jug. Plus when the liquid is lime juice it's not exactly all water but has citric acid as well among other things, so that changes the math - it's like NaOH doesn't have enough stuff to dissolve in initially, but at the same time, the citric acid neutralizes some of the NaOH and the reaction even gives out some additional water - see how complicated this is lol! Someone with chemical background can do the math and say if it's actually possible to properly dissolve NaOH in the same amount of lime juice, but I wouldn't risk it.

With that being said, if the soap works fine it's a win. Just make sure your next batch is not overly complicated and you pull such stunts only after you are more experienced

 

[DeeAnna]

A recipe will answer a lot of questions so we don't keep guessing.

My guess is the recipe has a high amount of water. What with freezing the soap and a generous amount of water, the free lye in the soap reacted with carbon dioxide in the air to form sodium carbonate (soda ash) rather than react with the fats in your soap batter.

Soda ash on soap often looks like a thin layer of white dust, but it can form large, obvious crystals if conditions are right. My guess is freezing the soap during saponification is the reason for this type of crystal formation.

People choose to freeze or refrigerate their soap when using dairy milk to prevent the soap from darkening from the heat of saponification. IMO there's no benefit to freezing/refrigerating soap made with coconut milk, however. The soap I've made with coconut milk has turned out nice and white, even though I never put soap in the fridge or freezer.