Soda Ash. Could it be my MOLD?

[Elysium]

Hello soaping folks,

So, I have 3 main soap molds: one is a 2# silicon log mold, the second is a 5.5# wood log mold with silicon liner, and the third is an acrylic slab mold.

EVERY TIME I use the acrylic slab mold, I get soda ash on top. Even when I'm using the same recipe and FO as I've used without ANY soda ash in the log molds.

I used to scrape off the tops of the slab mold soaps (sloughing off the tops to get to the pretty swirls underneath), but lately there has just been TOO much soda ash. And it's taking too long to clean or it isn't as clean as I'd like.

With all the soaps, I use 99% alcohol to spritz them every thirty minutes for 90 minutes after they've been poured. This does nothing to the slab mold soaps, it seems. I don't CPOP, but I do put them in the oven at about 165 degrees (and turned off) so they go through full gel.

However, I've tried not doing this, and it does't seem to matter.

Could it be the mold itself? Is acrylic (by any chance) more likely to have this problem? I will happily go by a silicon slab mold if it ends this nonsense.

Below is a picture of the same recipe, same FO soap -- one made in a log mold, one made in the slab. And me TRYING to clean up the slab one -- unsuccessfully!

All advice appreciated!

 

[navigator9]

I don't use acrylic molds, but I imagine you could do the same with them as you can with silicone molds...before removing the soap from the mold, just run the top of the soap under very warm running water at the sink, then let dry before removing. This should wash off any ash.

By the way, "I don't CPOP, but I do put them in the oven at about 165 degrees (and turned off) so they go through full gel." ...that is CPOP.

 

[Dahila]

I think it depens on ingredients. My dandelion soap gets so much ash even after I cut it, on the sides, Last time I made it, it had a bit of ash, I sprayed it twice at least with 99 alcohol

 

[Elysium]

I don't use acrylic molds, but I imagine you could do the same with them as you can with silicone molds...before removing the soap from the mold, just run the top of the soap under very warm running water at the sink, then let dry before removing. This should wash off any ash.

By the way, "I don't CPOP, but I do put them in the oven at about 165 degrees (and turned off) so they go through full gel." ...that is CPOP.

Oh! I guess I misunderstood. I thought CPOPers left their ovens on for a couple of hours and were trying to cut down on cure time.

Thanks for letting me know!

 

[shunt2011]

Oh! I guess I misunderstood. I thought CPOPers left their ovens on for a couple of hours and were trying to cut down on cure time.

Thanks for letting me know!

You really can't cut down the cure time. CPOPing just pushes along the saponification time. I too just put my mold in a warm oven, turn it off and let it sit in there until cool. Or I just put a lid on it and insulate it with some towels.

 

[Obsidian]

Soda ash is formed when lye in soap batter comes in contact with the air. Makes sense that a slab mold with its larger surface area could develop more ash.
Have you tried covering the mold with cling wrap after you spritz? You won't be able to CPOP it if you do but it might help with the ash.

 

[DeeAnna]

What lye concentration do you use? The bar in the upper right of your photo looks like it was pretty soft when you cut it -- not something I'd expect to see with a typical CPOP'ed soap. The bar on the left shows mottling (aka "glycerin" rivers); that suggests your water content is fairly high (low lye concentration).

 

[Elysium]

My lye concentration was 29%, so pretty high water. Which reminds me, I was reading this (http://auntieclaras.com/2015/06/overheating-soap/), and for a while I was master-batching lye at a 1:1.5 ratio and having much better results (until I used a rose FO).

I bet you're right in what I think you're hinting at: I should use a greater water discount.

 

[DeeAnna]

Yeah, that's what I was hinting at. "Full water" for a typical recipe with a blend of fats means about 28% so using a lye concentration of 29% is not a huge change, really. I gather you already have experience with 40% lye concentration (water:lye ratio of 1.5:1), but for others considering using less water in their recipe, I suggest trying 30% for a batch or two, then trying 33% for a couple more batches. See what works for you. Under 30% lye concentration, it can be tough to avoid gel. Starting about 30% or so, gelling becomes less likely. At 33% or more, I'd say gelling is unlikely.

 

[Elysium]

When you say gel... What do you mean, exactly? I'm a little confused.

 

[SuzieOz]

Elysium, I've had troubles just lately with more soda ash than usual - using the same recipes and moulds that usually work for me. I'm wondering if my problem is due to my house being cooler. We're going into Winter now - just wondering where you live and whether there have been changes in temperature lately.

Otherwise, I've also found (as said above) that the more water in my recipe, the more likely I am to have soda ash.

It can be quite tricky trying to work all the variables together to make a nice soap. Good luck!

 

[DeeAnna]

Gel is a physical state that soap can turn into. Soap in gel is not a solid and it's not a liquid -- it's somewhere in between. A soap in the gel state can have a translucent greasy appearance that is a lot like vaseline (petroleum jelly), so you will often see gel described as a "vaseline" look.

Many people think soap becomes a gel only when it is saponifying, but that's not true. When any soap gets hot enough for whatever reason, it will turn from a solid into a gel. Saponification is one time when the soap may get that warm, but you can also just add heat long after saponification is done and get soap to turn into a gel.

Soap turns into a gel at different temperatures based on its water content and the types of fatty acids in the soap. Some kinds of soap at room temperature are already in a gel state without having to add heat -- the KOH soap paste that people dilute to make liquid soap is an example.

Hope this helps!

When you say gel... What do you mean, exactly? I'm a little confused.

 

[Elysium]

So, when you say at 33% gelling is unlikely... How does gelling relate to the soda ash? I'm sorry if I'm being particularly dense. I'm learning a lot from you, and I want to make sure I'm not missing something. :?

 

[DeeAnna]

My main idea was to suggest that you will get less ash by using less water in the recipe. I can't guarantee that less water will get rid of ash entirely, but it can help.

I don't think you're dense -- I really think I'm not doing a good job of explaining clearly. By talking about gel, I meant to explain that using less water means your soap will be less likely to go into gel as well. I apologize if this was confusing -- I didn't mean to do that!

 

[Steve85569]

So, when you say at 33% gelling is unlikely... How does gelling relate to the soda ash? I'm sorry if I'm being particularly dense. I'm learning a lot from you, and I want to make sure I'm not missing something. :?

You are not being dense you are learning. There's lots to absorb here.

As the lye concentration increases the temperature at which soap will enter "gel" increases dramatically.

So by reducing the amount of water in the raw soap you reduce the chances of getting the effects of gel stage by a bunch even if you put the soap in the oven.

DeeAnna's suggestion for trying lower amounts of water is a good one. You'll be able to see for yourself what happens and doesn't happen as you reduce the water content of the raw soap. That's how a lot of us have learned.
At least she didn't give you the full on chemistry lesson (yet):mrgreen:.

Steve

 

[TBandCW]

I'm no soap expert, I found a recipe that works for me and stuck with it for all the soaps I sell. I had soda ash on top when I used a mold like this:
http://http://www.wholesalesuppliesplus.com/products/tray-soap-mold-12-beveled-square.aspx

When I switched to this mold with the lid (I use the silicon insert) no ash at all:
https://www.brambleberry.com/18-Bar-Unfinished-Birchwood-Mold-P5168.aspx

 

[penelopejane]

You can use a piece of cardboard for a lid and wrap in a blanket too. I don't think it's the mold I think it's the method.
I use a tiny spray of isopropyl alcohol now and think I've cured ash but I'm also using a higher lye concentration (or attempting to) on a few mixes so that could be an added benefit.

 

[dixiedragon]

Here's a pic of gel:
http://www.teachsoap.com/forum/viewtopic.php?f=2&t=5450

A dark, translucent spot starts in the middle of the log, where the soap is hottest. Most of us want either no gel or full gel, meaning we want the gel to reach from corner to corner. A partial gel results in a darker, translucent spot in the middle of the log when the soap cools and is ready to be cut. This is just a cosmetic flaw. The soap is totally fine and usable.

Here's a pic:
http://www.modernsoapmaking.com/troubleshooting-partial-gel-soap/

What Deanna is saying (she is very smart and mathy and I am not mathy, so this is my non-mathy-person interpretation) is that when you use the same amount of lye, but less water, the soap is less likely to gel. This is also a higher lye concentration. If you use the same amount of lye, but more water, the soap is more likely to gel. She gave us a bunch of mathy, science-y reasons for this. The consensus is that full corner-to-corner gel can stop ash from forming.

But there are some folks who get ash no matter how hard they try, and some people (like me) who very rarely get ash. My personal theory - it has nothing to do with ingredients and something to do with environment. I use tap water - no ash. I've used coconut milk - no ash. I've used distilled water - no ash. My personal theory is that curing in a cool, dry room helps. I cure in a finished basement room with a dehumidifier. I have a soaping friend who lives about 30 minutes from me. We use similar recipes - we're both lard soapers. But my curing room has a dehumidifier and hers doesn't, and she gets more ash than me.

 

[penelopejane]

Dixie dragon good explanation.
Some people get ash before they've unmolded the soap.
If ash is a result of the lye and water in the air mixing as it cures it must start with the mix method then be effected by the humidity as it saponifies and then by the humidity as it cures as well as it can show up later as soap cures.

Have just read scientific soap making re ash. It's complicated!