Soda Ash

Soda Ash

Soda Ash

You may have noticed that your handmade cold process soap sometimes has a light film of white “ash” on it.


This is Soda Ash.


Soda Ash is a result of the unsaponified lye in the soap reacting with the carbon dioxide in the air. It is completely harmless.


Many soapmakers like to leave this beautiful by-product of the soapmaking process on the soap as it doesn’t affect the quality of the soap and disappears after a couple of rinses. Others prefer to steam it off allowing bright colours and patterns to shine through.


Soda Ash can affect the colour of soap and intricate designs. The beautiful Woodland soap pictured below would have a white film on it which can be unattractive to customers although each bar would be unique.


woodland soap without soda ash


It can be prevented and removed in several ways.


  1. Covering the soap after pouring. Forcing the soap into a gel phase will help to prevent the formation of soda ash and keep colours bright and vibrant.
  2. Spritz with Isopropyl Alcohol – this then evaporates. However many soap makers don’t like to spray their soaps with this especially those who add toppings to their soaps
  3. Steaming the soap after curing. This can be done using a handheld steamer but can take time which many small businesses don’t have
  4. Making your soap at warmer temperatures. As soapmaking is a delicate process temperature can be a huge factor in creating designs and patterns.


I personally like to leave it on the soap. It can be beautiful. It is a part of making cold process soap.


What do you think?


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