Teach Soap

Hi everyone,

I've been soap making for six months and I've been on this board lurking for a while now.

Up until now I haven't had any problems with zapping or having any crystals forming, well up until two weeks ago. The last two batches of CP soap I've made have clear crystals forming on top of the soap during saponification. The soap first has some very small amounts of liquid come out of the soap during the first 24 hours of saponification. Over time the liquid turns into small square clear crystals. When I cut the soaps open there isn't any crystals in the middle but a few days later the liquid comes out of the soap and then the crystals appear.

I tried zap testing both the batches of soap over a number of days afterward (all over different parts of the soap) and there isn't any zap. I even zap tested a crystal and nothing happened.

The first batch where it happened was using the Carrot & Buttermilk recipe from the Soap Queen blog. (I've made this soap before and it didn't happen).
OO
CO
Buttermilk
Carrot Puree
Lye crystals

The second batch was my own recipe:
OO
CO
Palm Oil
Castor Oil
Lye
water
Lavender EO
Purple mica and titanium dioxide ITP swirl

Both batches were put in the fridge after pouring for 24 hours. Both batches used the same lye, OO, CO and were at 7% superfat, and were mixed at 110F. The lye container is half full right now and I noticed a couple of little clumps of lye sticking together which means that some water has gotten in.

I weighed both batches out correctly, I have a college honors degree in biochemistry (and subsequently a PhD although I'm not working in the field right now) so I've done a lot of lab work so I know how careful you have to be with measuring ingredients. But even if I did make a screw up in one batch I don't think I'd be able to do it twice in a row...

I thought for a while about it and I don't think it's the water because I didn't add any in to the buttermilk and carrot recipe. The only things in common are the lye, the olive oil and the coconut oil but I've been using theses batches on lots of soap but didn't have this problem.

Could it be the fat crystalising on top of the soap? Is the lye the problem? Is it putting the soap in the fridge? I'm really stuck here, I want to figure out what went wrong before I waste any more ingredients.

Any help would be greatly appreciated.

Thank you!

I had another check of the soaps this morning and there's no change. The crystals are all still there. I'm going away tomorrow for 5 days so I guess I'll have to play around with the ingredients to figure out what went wrong when I get back.

Here's some thoughts.....
Are you using room temp water and stirring the lye water til it's clear? Are you using flakes or beads? Are you letting the lye water cool off by itself or do you speed up the process by adding ice or putting the lye water in the fridge? Do you premake the lye a couple of days in advance? Is it cold where you are?
Do your soaps normally gel or do you try to prevent geliing by putting the soap in the fridge? Are you insulating the soap with towels or blankets?
Buttermilk & Carrot Puree both have natural sugars. Is it possible that your soap is overheating?
Have you tried putting your soap into the freezer instead of the fridge?
Can you lightly insulate it and let it go into gel all by itself. Just keep an eye on it so it doesn't overheat.
You can elevate the mold and put a fan on it to keep the soap cool so it doesn't overheat.

_________________
Irena
Closed minds are like faulty parachutes; they refuse to open.

Thanks for your help soap buddy

Normally I use room temperature water and stir the lye (looks like sugar crystals) till it's clear. I then leave the lye to cool while I heat the oils. I prep the additives to the soap while the oils cool down.

I always make the lye fresh each time.

Here in NZ it's currently spring and the temperatures have been rising which is why I've put the last two batches in fridge (especially the carrot and buttermilk puree since I didn't want it to overheat). All previous batches were left to saponify at room temperature because the temperature was quite cold in the room I normally soap, most of them either didn't gel or they partially gelled and I got the power rings in the middle.

I haven't tried putting the soap into the freezer. Maybe I should try again and insulate them slightly and let the soaps do their thing. I have a small fan which might help too. Would it be better to do it the same size as the previous ones or make smaller test batches?

I would make the same batch size, elevate it and put a fan on it. Smaller batch size has a smaller volume and you might not get the same results.

_________________
Irena
Closed minds are like faulty parachutes; they refuse to open.

Thanks. I'll try that when I get home in 5 days. We're going on holiday tomorrow and all I can think about is obsessing over why my soaps aren't working

Just curious...

Is this an aesthetic issue or does it affect the quality of the soap? I ask because I got some pretty good crystals on the coconut oil soap I made. I just sliced it off and used the soap which happens to be wonderful! I can see how it would be an issue with a fancy textured top, etc....

I'm worried about it being both. When I cut it up the crystals were on the inside so I was worried it'd make the soap scratchy. My other worry was that it was sodium hydroxide if the soap was lye heavy.

I did some research and talked with a chemist friend of mine and she suggested it might be crystallized glycerin/glycerol. Crystal glycerin forms at low temperatures aka in a fridge when soap is bought up slowly up to room temperature afterward. It doesn't happen very often but once it does seed crystals on any equipment etc means that it's more likely to happen more often again and again.

The test for this is to collect some crystals, apparently the crystals will melt at exactly 17.9 degrees Celsius. I'm gonna collect some crystals and do the test. If so, case closed. It'll mean I'll have to wash all my equipment again preferably in a dishwasher to try and get rid of the seed crystals to stop it happening again.

Glycerol crystals shouldn't be present at room temperature, unless you keep your house decently cold. Do you use distilled water?

Nearest I can tell is that you are forming "soap crystals" cause by rapid temperature change of the batter. This causes sodium to crystalize on the surfaces, even after you cut it. These can continue to form for the entire cure. They are not dangerous, but can make the soap a little bit scratchy as they are generally also inside the soap. Most of the articles I read suggest rebatching the soap with slightly more liquid than regular rebatch and a 4-6 week cure to let the water evaporate. The extra water helps dissolve the sodium crystals. The best way to avoid soap crystals is to either insulate or slowly cool the batter.

Hope this helps!

_________________
~~Heather~~
Mad [soaping] Scientist

Thanks for the help Heather.

I finally got around to testing it out a couple of days ago (I was sick all last week) and it formed on the batch which saponified in the fridge, but not the one which saponified at room temperature.

I live in New Zealand and it's still spring here so it's been pretty cool temperature wise. I'm wondering what will happen as we head into summer.