What are your best practices for preventing soda ash?

Soapmaking Forum

Help Support Soapmaking Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
I very rarely get ash (even my salt bars don't have ash). I have no idea of the mechanics behind it, so my general process:

I use tap water. I use 35% water (percentage of oil weight). My oils are about 100 and my lye is room temp. I gel. I cure my soaps in a room with a dehumidifier.
 
I used to get a lot of ash on lavender soap in particular. I usually prefer to soap at cooler temperatures, but I found that if I used very warm oils and lye, there was much less ash on the lavender soap. Also, spraying with isopropyl alcohol does seem to help - I usually do it a couple of times while it coming to gell state to get a nice even mist over all of the top, then leave it alone as it cools down, covered.
 
I have tried the alcohol thing. It doesn't work for me. I have been using some of the 96% "heads" I get from running my still. That stuff is good if you want to set things on fire or throw in the eyes of your enemy. Also makes good window cleaner. Just doesnt help with ash on soap.

I have found since I have switched from using "full water" to 33% lye concentration and cpop my soaps I'm not getting ash anymore or if I do ts really light.

I made a batch today at 40% cpop so will see how that goes over the coming few days
 
I agree that less water in the recipe tends to reduce the amount of ash. At 30% to 33% lye concentration, I will get a thin film of ash on the top of some soaps, but seldom much more than that. When a bunch of us were doing the infamous "super lye heavy" Andalusian castile experiments about 2 years ago, we were using around 15% NaOH concentration to make this soap. The ash that formed on these soaps was impressive. A few bars looked like they were growing fur or a coating of fluffy snowflakes.

I believe I get less ash when I soap in the winter (less humid) months compared to summertime when the humidity runs 80% or higher.
 
I made a batch once with 50% water as percent of oils because I wanted very intricate swirls. I'll never do that again! The ash was sooo bad that you couldn't even see the design since it was a slab.

I get more ash on non-gelled soaps as I do with gelled soaps. I get no ash on my soaps with a 45% lye concentration when I gel them. If I don't, I get a very very thin coating. On my 33% lye concentration batches, I regularly get a thin coating of ash on the tops of my loaf. Some scents it's worse than others. I also notice if I cut too early that I'm more likely to get ash (when the loaf is still warm). If I allow it to cool in the oven completely before cutting, I get a lot less ash. I'm in a very humid environment although I'm not sure that has any effect.

I am somewhat convinced that getting too close to my soaps when they are not finished saponifiying, and they are uncovered and I breathe on them that the likely hood of ash goes up. I could be crazy there! I was going to test it one day but small amounts of ash really don't bug me much.
 
I've found that for me, it's easier to remove it than to try to prevent it. I used to cover the top of the soap after pouring with saran wrap. The wrap has to touch the surface of the soap, and you know how much fun it is to deal with saran wrap, so imagine trying to get it smoothly over the top of your soap. Then for years, I sprayed with alcohol. I think it helped a bit, but I found it made the tops of my soaps kind of sticky. And then one day, I was watching a youtube video by Ariane Arsenault, where she took a whole loaf of soap, still in its silicone liner, and held it under the faucet, running warm water over the top to remove ash. I smacked myself on the forehead and thought "Now why didn't I ever think of that???" It was one of those light bulb moments...you do the whole loaf at once. It can be done bar by bar, but this is so much easier. Steam also works, if you have one of those clothes steamers. But it's so simple to just hold the whole darn thing under the faucet, that since that day, I've never done anything else. Hope this helps.
 
After reading through this and everything else I could find (I'm a new soaper) It seems like people are having a lot of seemingly contradictory experiences. Some think soaping at room temperature prevents it and some think at high and I'm just wondering if possible temperature has nothing at all to do with it and if the issue might not be humidity and evaporation rates in addition to speed of saponification. So higher temps works because it speeds up evaporation rates but maybe the people doing it at room temp find that works because however they are heating oils or whatever is creating higher humidity in the room. Please tell me if any of this just sounds completely stupid. I'm just trying to make sense of the completely different experience people are having.
 
Part of the reason for different experiences is that no two people are using the exact same recipe (oils, ingredient temps, colors, fragrances, additives) or process (emulsion v. medium trace, for instance). Nor are they making them in identical environments (heat, humidity, air exposure). All of those things affect whether one gets ash, and how easy it is to remove it.

For instance, with some of my recipes, it would do no good to wash the whole loaf of soap before cutting - because the ash shows up later, over time. It's best if I wait till the bars are cured if I want to remove the ash for good.

So yes, you will see many different suggestions. All of them work for some, but few work for all.
 
I cover the batch with a strip of silicone, then the wooden lid of the mold. Leave until completely cold, then a few hours after. I never get ash.
 
I never used to get ash until the day I certified my recipe for sale, then I got worse ash every time I made it! I always used to refrigerate my soaps to prevent gel as gelling messes up my natural colours. But the ash seemed to affect the inside and bottom corners of the soap as well as on top so I tried cpoping in desperation despite the effect on the colours but I still didn't find it really prevented ash. Covering didn't help as most of the ash seemed to start on the corners at the bottom of the mould. In fact mine were always fine until a few days after unmoulding when the ash and crumbliness would just start to develop. I always soaped at 33% because everyone seemed to recommend this for preventing ash. Finally I read a thread about someone who reduced their water further and got results and I took my water ratio right down to 1.5:1. This has worked, my last batch had no ash and refrigerating them to prevent gel has meant my lovely natural colours are back.

So my view is that all the other suggested options, cpoping, soaping at higher or lower temperatures, covering (I never tried alcohol except to drink after each failed batch!), None of these worked for me but considerably discounting my water did. Maybe you don't need to discount as radically as I did, but it works for me.
 
Im on the soda ash struggle as well. I usually do not get ash if I pour at a thicker trace, but I notice I get it more when Im trying to do swirls or some design that requires a lighter trace. Today I unmolded and cut my lavender bar and had quite a lot of ash, im thinking due to light trace pour PLUS the lavender EO. I have tried alcohol spray but didnt seem to work for me. I have never tried CPOP and perhaps I should give it a go. I do sometimes cover with saran wrap but that tends to leave water spots on the top.

QUESTION: If I want to steam the ash, when should I do this? Also Ive read running the bars under cold water helps? But when do I do this? Im thinking closer to the full cure time? Thanks!
 
I read in a book that you should spray the top of your soap with 91% alcohol and that that should eliminate the ash. I have never done it as I have yet to get ash.

Robert
I spray the top of my soap with 91% alcohol and it works fine on the top. In fact, the 91% alcohol on top has stopped my soap from discoloring on top, which just looks odd when the rest of it has darkened. (see pic below) And I use a 33% lye concentration.

But I get ash on the edges and cut sides after I cut. And if I use individual molds, like my stone shaped silicone mold, the whole thing ashes up. :smallshrug:

1633378704976.png
 
I spray the top of my soap with 91% alcohol and it works fine on the top. In fact, the 91% alcohol on top has stopped my soap from discoloring on top, which just looks odd when the rest of it has darkened. (see pic below) And I use a 33% lye concentration.

But I get ash on the edges and cut sides after I cut. And if I use individual molds, like my stone shaped silicone mold, the whole thing ashes up. :smallshrug:

View attachment 61447
Like you, after pouring my loaf molds, I spray with alcohol, cover with plastic wrap, cardboard, and then a pile of towels to gel. I have never gotten soda ash since doing these steps.

I am used to unmolding in 24 hours. My leftover batter goes into individual cavity molds the size of one bar. When I unmolded them after 24 hours, the sprayed top stayed ash free -- but all other surfaces got it big time. Now I leave the soap in the mold several days before unmolding. Perhaps you can try waiting (I know, I know) to unmold?
 
Like you, after pouring my loaf molds, I spray with alcohol, cover with plastic wrap, cardboard, and then a pile of towels to gel. I have never gotten soda ash since doing these steps.

I am used to unmolding in 24 hours. My leftover batter goes into individual cavity molds the size of one bar. When I unmolded them after 24 hours, the sprayed top stayed ash free -- but all other surfaces got it big time. Now I leave the soap in the mold several days before unmolding. Perhaps you can try waiting (I know, I know) to unmold?

WAIT!?!?!?!?! What is the "wait" of which you speak?
 
After pouring into loaf mold depending on the formula spray with 91% alcohol and wrap with plastic wrap. In other cases spraying with 91% alcohol works perfect.
 
Back
Top