BASICS OF PRESERVATIVES
Preservatives are an important part of DIY bath and body products. They help prevent mold and bacteria growth, which extends the shelf life of products and makes them safe to use. Check out this post for more information on the options we carry and how to use them.
Preservatives are recommended for products made with water or products that may get water splashed in during use. This post has information on whether they’re needed for soap, lotion, and more. Keep in mind these are general rules and may be different based on your preference, how the product will be used, whether you’re selling the product, etc. It’s a great place to start and adjust from there.
Cold process and melt and pour soap
You never have to worry about adding a preservative to cold process or melt and pour. They have a pH level of 9-10, which doesn’t allow mold or bacteria to grow. Just another reason to love handmade soap.
If you make a product with water, you need a preservative. Anhydrous products (oil based) don’t need preserving, although products that might come into contact with water, like scrubs or in shower lotion bars, require preservatives.
Cold process soap (made with sodium hydroxide) does not need a preservative. For other high pH products such as liquid soap, generally if the pH is above 10 a preservative may not be required. If the pH is below 10, an expert microbiologist advises liquid germall plus can be used (despite the supplier recommended use below pH8). Alternatively, Suttocide A or Glydant Plus can be used.
It’s a common myth that anti-oxidants like vitamin E, Grapefruit Seed Extract and rosemary extract are preservatives but they are not. Oxidation of oils and butters leads to rancidity and anti-oxidants slow down this process. These anti-oxidants do not prevent bacteria, yeast, or mold from spoiling your product. (Yeasts and molds are fungi).