How to keep silicon molds dust free ?!

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Well-Known Member
Nov 2, 2023
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I'm so disappointed that my last batches of soap, which are on the white (whitish), ended up encrusted with dust on the sides touching the mold.
I clean them after use, then store them in a clean and closed container but they still have dust on them when I use them !
My best guess is that I have to wash them again right before using and then airdry them upside down, because if I dry them with a towel, I seem to actually rub more dust on it, even with some sort of microfiber towels.
Is there an other trick ? Maybe less time consuming
I don't think there's a better way. Maybe zip em up in a nylon bag?
Only takes a sec to dunk em in the sink n turn em upside down in washer machine. It doesn't have to be bone dry. A few drops water in my mold before pouring won't hurt anything. I wash molds very first thing so they can dry while in preparing everything else.
I don't think it's ash, I'm not experimented but I think I've seen it on other soaps and it's not that.
Maybe "dust" is not the right way to describe these tiny things.
If it was visible on my silicon mold before pouring, I didn't see it ;)
But it doesn't look like the white stuff showed on the thread you're talking about @Nona'sFarm .

Thank you all for trying to help, I guess I just need to clean my molds better and right before using.


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It's hard to see much in the picture you posted, but that absolutely could be soda ash, which can take on a lot of different forms, including bumps, crystals, or powder.

It could also be a form of "silicone rash," although my experience with that tends to be holes or indents in the areas touching the mold, rather than bumps.

Honestly, I have some silicone molds that create whitish edges on my soaps, no matter what recipe I use, whether I gel or don't gel, etc. My more expensive molds from reputable soap sellers never do this; only the less expensive ones from Amazon or AliBaba. Some of the cheaper molds started out fine, but eventually started giving these bad results over time.

As a result, I'm convinced that some molds are made with inferior quality silicone that reacts with the caustic soap batter in a variety of unintended and unpleasant ways. I keep meaning to try greasing them with some mineral oil to see if that helps, but haven't remembered to do that yet. If you give that a try, please let us know if it resolves the issue for you. :)
But isn't soda ash supposed to be white ? It is indeed difficult to see on the picture, but I'm talking about tiny black specks on my white soap. Might look like nothing on the pic but when I look at my soaps its all I can see 😔

Still good to know that not all silicone molds are made equal. This particular one I bought at a yard sale and don't know where it was bought from originally.
Oh goodness, I didn’t think you were talking about black specs. I couldn’t even see them until I enlarged your photo quite a bit. But I do see them now.

Are you sure those are coming from the molds? I am wondering if there is something else happening during your process that is introducing those specks, which are then sinking to the bottom of the mold.

That was actually happening to me from one of my stick blenders. I couldn’t figure out where these little specs were coming from. When the stick blender broke, I realized it was probably tiny pieces of the plastic flaking off from inside before the connecting piece finally sheared off.

Another stick blender had gotten product up inside the shaft where it couldn’t be cleaned. Bits of it would come out whenever I used it. 🤮 That one had to be trashed, too.

I’ve also had some batches of lye that had black flakes in them (Red Crown from the hardware store). I had to strain every batch of lye to keep those tiny black flakes out of my soap.

Those are just some theories that come to mind. But in case it is coming from the mold, I’d try rinsing the mold right before using it, and then greasing the mold cavities very lightly with some mineral oil or Vaseline. That should seal off the mold surfaces well enough to prevent anything in the mold from reacting or coming off into the batter.
It could be from any oh my utensils that had not been cleaned properly too. Maybe my bowl was dusty ? Or my blender (it's white, so I think I can cross bits of it oh the list of suspects).
I suspected the mold first because I find that all my molds attract dust like crazy. And I find it a pain to constantly wash them. But I guess there is no way around.
Thank you for the tip on mineral oil.

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