Not sure of the cause

[Todd Ziegler]

I'm not sure what is causing this problem that I have circled. I have had it happen before and I can't seem to find a common thread to connect each time it happened. I force gell all of my soaps and it doesn't happen every time. I thought it was vanillin discoloration but it has happened in soap batches that had no vanillin and I have used all my 0% vanillin FO's several times without discoloring. I have used the same recipe for every time it happened. I think it is FO related but I can't confirm that, so I am hoping someone else might have an idea of what is going on.

My recipe castor oil 5%, palm oil 10%,HO safflower 11%, coconut oil 22%, lard 52%, sodium lactate 3%, FO 5%

 

[TheGecko]

I'm assuming you're using silicone molds. Do you wash or rinse them between batches? If it's been a few days since you used them, do you rinse them out?

I store the majority of my molds in the garage...I have cats and live in a dusty area. I always give my molds a good rinse in hot water and dry thoroughly if it's been a couple of days since I last used them. And I like to wash them in hot, sudsy water or the dishwasher every few times to make sure there is no build up in the edges.

 

[Todd Ziegler]

I do use silicone molds. I wash them with sudsy water, dry them and then I use isopropyl alcohol and wipe them down before I use them. That is a common thread that I thought about but didn't think that it was the cause of it. However since you are mentioning it, I am going to give it more thought because it is the only thing that they all have in common, period.

I repeated the same batch today, to see what happens. It's not an every batch occurrence but I want to figure out what is happening. Also, I'm pretty sure that it has happened in 2 very different silicone molds but after checking my records, I think the majority of the affected bars were from the mold that I used yesterday and today. I don't keep track of the molds that I used for each batch but maybe I should.

I actually pay special attention to the corners when I clean my molds. Early on in my obsession that is soap making, I didn't see a little piece of soap until I unmolded a batch and saw it.

I will know more tonight when I unmold today's batch.

 

[lsg]

It does seem that the discoloration is in the corners. If the discoloration hasn't spread, then I would guess it is a problem with the mold lining.

 

[Ford]

I know it should not be possible. But looks like a portion of uncolored batter. Was it in corner both times?

 

[DeeAnna]

If you look closely at the boundary between the white center and the yellow corner, you'll see an odd speckled texture where the soap looks pale and more opaque, even through the pink portion. The other lower corner is cropped out of the picture, but it looks like there is a similar pattern there.

If it was an FO (or other) contamination of the mold itself, I would expect a thin rind of discoloration. There's no reason for contamination to spread inward as far as it has and only at the corners.

I honestly don't know this to be the case, but I wonder, Todd, if this is an unusual type of partial gel. The odd speckly boundary looks suspiciously like partial gel, even though you say you force gel.

 

[Todd Ziegler]

If you look closely at the boundary between the white center and the yellow corner, you'll see an odd speckled texture where the soap looks pale and more opaque, even through the pink portion. The other lower corner is cropped out of the picture, but it looks like there is a similar pattern there.

If it was an FO (or other) contamination of the mold itself, I would expect a thin rind of discoloration. There's no reason for contamination to spread inward as far as it has and only at the corners.

I honestly don't know this to be the case, but I wonder, Todd, if this is an unusual type of partial gel. The odd speckly boundary looks suspiciously like partial gel, even though you say you force gel.

The cropped out corner looks the same. If I would have took a picture before I cut the soap, you would have seen in the dead center of the soap that it had no problems. It was only as you got closer to the ends did it get worse.

When it first happened a few months ago, I thought it was the result of a partial gell. Even though I force gell, that doesn't mean that the whole soap will gell. And I know that it gets hotter in the middle then it does on the ends but I thought it would look different.

I know that it isn't leftover batter or FO in the mold because I pay special attention to cleaning the molds.

I repeated the batch yesterday and I let it gell longer than the previous batch and it didn't have any problems. So I think it is a result of not gelling.

Thanks everyone and if you think of anything else please let me know.

 

[Todd Ziegler]

I know it should not be possible. But looks like a portion of uncolored batter. Was it in corner both times?

That area just had confetti in it, no coloring. However I agree with @DeeAnna that it is a gelling failure.

 

[Todd Ziegler]

It does seem that the discoloration is in the corners. If the discoloration hasn't spread, then I would guess it is a problem with the mold lining.

That was my first thought but I pay special attention to the corners because I had some leftover one time and since then I use isopropyl alcohol to clean the corners and the whole mold before I use it.

 

[SoapDaddy70]

I think I have had the same issue a couple of times. See this post of mine. Soda Ash or something else?
This happened again to me recently. Both times it happened it was a batch I made in a 4 bar silicone mold.

 

[AliOop]

I will be no help at all, but just have to say that the problem may be the cranky attitude of the soap shreds. That little guy in the mis-colored corner is obviously quite out of sorts. Mr. Grumpy-pants.

 

[SoapWitch]

A bit of saponified soap doesn't seem it would cause discoloration, unless that soap was a discoloring soap like brown, due to a fragrance oil. If additional soap were the case confetti (shaved pieces of soap added to batter) would do the same. Saponification is harsh process, but additional soap like embeds etc won't cause discoloration, but can affect the colors. It could be unmixed soap, fragrance oil (even unmixed properly) or oils that might have gone bad. Oils that are "bad" is a tricky thought as even bad oils can be made into soap. OR, this could be colors of previous batches left behind, in which case it is no longer discoloration, but colors from previous batch affecting. Does any of this suit? And it certainly appears the color is coming from the corners. I wonder, have you run your molds through the dishwasher? That could help with understand where the color is coming from in future batches.