Common visual blemishes on cold process soap

Common visual blemishes on cold process soap

Cold process soap is handcrafted from start to finish. As a result, there are some common things that can occur during soap making to make the final appearance of the soap appear as if the soap is blemished.

But fear not. Today I explain to you common things you will see on cold process soap and why they occur.

Gel Phase

Gel Phase occurs during the soap making process and usually happens as a result of the temperature of the product. It doesn’t affect the quality of the soap but it may affect the appearance. Some soap makers force their soap to go through gel phase as it can give an almost ombre type appearance or make certain colours more vibrant.

Our soaps tend to go through partial gel phase on their own because we live in a sub tropical climate. Warm temperatures are key to enacting gel phase and in Queensland we have more warm temperatures than cold. But during winter time, we have much drier and cooler days and nights compared to the more common humid days in the summer. Additionally, if the room or area one soaps in goes through temperature fluctuations, this can also encourage gel phase.

Gel phase does absolutely nothing to the usability of the soap. Gel phase will only appear as darkened edges on a final product that has cured, and in some instances fade significantly and disappearing. So if you do see gel phase on your soap or what appears to be a slight colour difference, fear not. Your soap is still very safe to use and gel phase makes no impact on the final product.

Glycerin dew or glycerine rivers

Melt and Pour soap is often used in CP soap making to add additional layers or dimensions in the form of embeds. Often MP soaps are also made to test additives in soap. We use MP soap in a variety of ways, but mostly as embeds and testers. We sell these MP soaps.

MP soap has added glycerine into the base during the manufacturing process to make the soap base easier to work with and also acts as a humectant. Humectants merely draw moisture from the air and onto the skin, but MP soaps specifically and in tropical climates may attract glycerine dew when sitting on the counter.

This does not affect the quality or usability of the soap. Glycerin dew can be unsightly, but that’s because the soap is ‘sweating’ due to the temperature in the environment.

Glycerin rivers tend to occur more in cold process soap and much more visible when using pigments. We use clays to colour our soap and currently do not have glycerine rivers showing in any of our soaps. Glycerin rivers occur when, during the soap making process, the soap batter gets too hot which causes the glycerine to congeal, making the rivers more visible.

Soda Ash

Soda Ash is completely harmless and you’ll see soda ash on cold process soap more often. Soda ash appears as a white, ashy type of film on the very surface of the bars, and often on the top. It is totally harmless.

Soda ash tends to form when unsaponified lye reacts with naturally occurring carbon dioxide in the air. It does not affect the soap bars and is completely safe to use. It can obscure more intricate designs, especially if a soap maker is doing elaborate swirls. On very rare occasions it can run through an entire bar length of soap or make the soap feel crumbly.

Soda ash occurs as a result of temperatures used during the soap making process. Cold process soap is called so because it doesn’t require heating. But where heat does occur is when sodium hydroxide (lye) is mixed with water, and the chemical reaction causes heat. As a result of this heat, and particularly our use of hard and soft oils, we tend to soap at 110-120 F and mix our batter to medium trace to ensure our soaps are less likely to get soda ash (though we have had a batch fail when we did the opposite of this and it failed!)

Back to blog