Is it possible to use a Chelating agent in M&P soaps?

[BlueRaven]

I understand that a chelating agent gets to react with the lye solution in cold process soap making, but I was wondering if I can add any chelating agents to an M&P soap as well (the reason I'm looking to use a chelating agent is to prevent the oxidation of the Matcha green tea additive that I am including in my S&P soap base). I would greatly appreciate any advice

 

[not_ally]

I don't think you need a chelator to prevent oxidation with MP, assuming the base isn't expired. If it's a good brand I would think that they used fresh oils and anti-oxidative processes (ie; no metal equipment) to make the base. I've never experienced DOS or any other symptoms of oxidation with the MP brand I use (SFIC), even after a year+ of storage. In soaping terms, oxidation usually refers to oils going rancid, I don't think chelation/the same preventive methods would apply to matcha powder.

ETA: are you in Cardiff, Wales or Cardiff, California?)

 

[BlueRaven]

I don't think you need a chelator to prevent oxidation with MP, assuming the base isn't expired. If it's a good brand I would think that they used fresh oils and anti-oxidative processes (ie; no metal equipment) to make the base. I've never experienced DOS or any other symptoms of oxidation with the MP brand I use (SFIC), even after a year+ of storage. In soaping terms, oxidation usually refers to oils going rancid, I don't think chelation/the same preventive methods would apply to matcha powder.

ETA: are you in Cardiff, Wales or Cardiff, California?)

I'm using Stephenson soap base which should be okay. I add matcha powder to my soap and it turns out a beautiful green. Sadly, the colour gets darker over time which I think is the result of the matcha powder oxidizing. I haven't managed to find much information about how to prevent this, but I half thought that a chelating agent might be helpful. But what you said makes sense. I'll try to figure out some other solution. Thanks!

I'm from Cardiff, Wales

 

[DeeAnna]

If you want to experiment with an additive that might keep matcha from oxidizing, you'll need to use an antioxidant.

The purpose of a chelant is to immobilize metal ions that can accelerate the process of oxidation. A chelant does not directly prevent oxidation because oxidation occurs for a variety of reasons, not just the presence of metal ions.

I don't think an antioxidant is going to solve your problem, however, because I suspect the color change is more due to the alkaline pH of soap. If the browning is caused purely by oxidation, then botanical colorants buried deep inside a bar of soap shouldn't fade or turn brown.