soda ash (4 of 5) pieces homemade soap

How to Remove Soda Ash from Homemade Soap

Do you know what’s a frustrating problem for any soap maker? Soda ash. I tried all the tricks before I learned how to remove soda ash from my handmade soaps in a way that was easy and effective.

What is it and how it is formed? It is scientifically called Sodium Carbonate. When the carbon dioxide in the air combines with the sodium hydroxide in your freshly manufactured soap batter before saponification is complete, soda ash is created.

Soap without soda ash (left) and with soda (right)
Soap without soda ash (left) and with soda (right)

From shaving it off the outside layer, steaming it, and spraying it with alcohol. Nothing really worked well in my opinion. Some recommend preventative measures by spraying the freshly poured soap with 99% isopropyl alcohol but my mold has individual cavities and the ash also forms after coming out of the molds on the 5 sides where the mold covered the bars so that’s not really going to work.

How To Remove Soda Ash From Handmade Soap
Soap with white dusty residue

Soda ash also seems to be a seasonal problem for me, though I don’t understand why that would be… it always gives me the most problems with the soap I make in the fall and winter.

Some types of soap seem to be more prone to it than others. I’ve had it on my Homesteader’s Tallow Soap on occasion, but have yet to see it pop up on my Gardener’s Super Scrub Soap. Bizarre. It really drives me up the wall when I make a pretty swirly topped Flower Infused Milk Soap with herbs I got from my herbal garden and all the lovely peaks and valleys are ash-dusted like snow on a mountain range. Super frustrating!

Thankfully, it is perfectly harmless and is only a cosmetic problem. (Pun not intended.) If I were making soap just for personal use, I wouldn’t worry about it at all, but if you would like to give your bars away as a gift, then you’re going to want them to be beautiful I’m sure.

So when my bars start looking like they’ve got white mold, what do I do?

How to Remove Soda Ash from Homemade Soap

Consider wearing gloves so you don’t leave any fingerprints.

1.) Use a spray bottle of water set to mist and finely spritz your bar of soap with the water.

2.) Use a dry, lint-free rag to polish the soda ash away.

3.) Brush the rag across the surface of the soap in one direction.

4.) Blow dry each side that you need to clean until it is fully dry before handling it with your fingers.

Couldn’t be any easier, could it? (Unless it wasn’t there to begin with).

Have you learned how to prevent soda ash from forming on your handmade soaps?

Farmstead Soap and Salve from Reformation Acres
Farmstead Soap and Salve Reformation Acres

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  1. I find the best prevention is to leave the soap longer than my patience would normally allow. If I give it a good 48 hours I’m much less likely to experience soda ash. It’s excruciating because I wanna see those swirls! I wanna know how it all turned out!

    I also use isopropyl alcohol, spritzing them as soon as the finishing touches are made in the new soap. I’m not too worried about that being considered an additive as I’m sure it 100% evaporates later.

    If all else fails your method is the same as I use. Even if preventative measures fail, at least you won’t have super thick soap ash.

  2. Hi I use magic spongers to clean off the ash they don’t leave any fabric behind you can get them cheap on eBay

  3. Thank you! I am just about to start trying to make soap for the first time. Glad to have this knowledge tucked away for if I need it! Have a great day!