Glycerine Rivers & Soda Ash – How To Manage

Two more soaping terms you will come across in your craft are glycerine rivers and soda ash so lets cover these terms and how to deal with them.


Glycerine Rivers

sometimes called crackle are a visual effect in colored sections of a bar of soap that look like a crack or fractured color change.  They do not harm or affect the quality of your soap. These are distinctive striations in your design that can look like rivers. Now, there is a whole science behind this but most commonly soapers want to know how to control this effect.

Typically this will happen with certain color pigments like ultra marine blues and titanium dioxide and it happens when the soap is going through the gel phase and becoming hotter. During the chemical reaction that’s happening water will pool together in some places in the bar in different density. Since glycerine is a by product of soap, it is also being formed in different densities and this crackled look is created.

The remedy for this is to give your recipe a water discount. Use 10 percent less water, make sure you’re colorants are mixed well, and pour the batter at a slightly thinner trace. You may need to practice this a few times before you get the hang of controlling your glycerine rivers, but with a little practice it will work.




Soda Ash

Soda Ash is an effect that happens on the surface of your soaps when some of the lye hasn’t been saponified and it reacts with carbon dioxide in the air. That can occur over time during the curing process, or it can take several weeks.

This soap was a little unusual because it ashed in spots like chicken pox. This ash developed a year after it was made.

This can be tricky because there could be a few reasons why your soaps can ash.

The most obvious reason is that your lye wasn’t mixed well enough or you have just a bit too much lye in your recipe. These are easy remedies that can be fixed by mixing or measuring more carefully.

Another  reason can be the humidity in the room during the curing process. If you have followed your recipe correctly and you seem to have a chronic problem with soda ask, then try putting a dehumidified in to the room or try curing in a place that is more dry. If you’re still having a problem that doesn’t feel identifiable to you then you can take some preventative measures  to keep the ash from forming that might be helpful.

Here is a BEFORE image of a bar that developed soda ash before it was done curing.


First, before you set your batter aside to cure spray the top with 99% isopropyl rubbing alcohol, also place a flat piece of cardboard over the top of the mold as it is setting up. This will minimize contact with the air while your batter is becoming harder. You can do this too during the curing process by placing the bars just a half inch from each other and placing a price of cardboard on top of them. Don’t let your curing bars touch each other. You want them to be able to breath and allow the water to evaporate.

If this is still a problem, try working with a bit less water in your recipe. Reduce the water in the recipe by only 10% . This is best if your oils are soft. It might not be possible if you are working with hard oils.

So if you have soda ash, how do you get rid of it?

The first thing to know is that soda ash does not affect the quality of your soap. So does it bother you enough to do anything? It’s only cosmetic. If the answer is yes, then put on a pair of gloves and wash your bars. Rub the surfaces until that thin layer of ash comes off. This is pretty easy.

If you don’t want to lather up, then just wet a paper towel and use that as a rub. Finally, if you have too many vars to clean off individually, you can steam them off. A hand held clothing steam is just the thing for the job, but if you aren’t sure about what kind of out come you can get with one of these you can use the steam from your tea pot. Hold it over the hot water steam for just a minute and rub the humidity across the bar. This will remedy your soda ash.

Here is the same bar AFTER it has been washed lightly with the scrubby side of a kitchen sponge.

If you need to adjust your recipe and reduce the amount of water. Go ahead and run it through our soap calculator, just to double check and be sure to print a copy for safe keeping.

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