Sunday, January 29, 2012
When should you use a preservative?
If you want to make an oil in water lotion (what we normally make), you must add a preservative. If you change every millilitre of water in the lotion to being honey or aloe or a hydrosol, those are still water based ingredients and you must add a preservative. If you make a body wash, shampoo, conditioner, or any other product that contains water or a water like ingredient, you must add a preservative.
If you have a product into which someone might put their wet hands - for instance, a sugar scrub - you will need to add a suitable preservative. (Click here for more information on water activity and preserving!)
Let's go back a step...What is a preservative? Preservatives help prevent microbial growth in our products, which can cause separation of our emulsions, speed up rancidity of our oils and butters, and cause weird smells and colours.
Vitamin E is NOT a preservative. It is an anti-oxidant that can help retard rancidity, but it is not a preservative that will prevent microbial growth.
Citric acid is NOT a preservative. It can be used as an anti-oxidant that can help retard rancidity, but it will also mess with the pH of your product (making it more acidic by 1 pH at 0.2% or so).
Grapefruit seed extract is NOT a preservative. (I've gone into greater detail about this in this post.)
Essential oils are NOT preservatives. They might have some anti-microbial features (like eugenol), but none of them have been proven to be effective preservatives in our products. (More about this tomorrow!)
Raymond's amazing homemade ice cream and I still get sick. It sucks, but that's my reality. I don't get to eat ice cream or drink egg nog or enjoy cake with tons of whipped cream. In a similar vein, if you are allergic to preservatives, if you want only 100% organic products, if you're against them somehow, or if you don't want to spend money on more ingredients, then you don't get to use water containing products and will have to stick to anhydrous products.
I know this sounds harsh, but this is the reality. I don't care how many blogs or suppliers out there try to convince you that you can make products that don't contain preservatives, you can't make a water containing product without a preservative, and writing to me to ask for my blessing to make a water containing product without a preservative is pointless. It's like asking your vegan friend to grill you up a tasty steak - it's not going to happen.
Preservatives - a whole bunch of posts on the topic
Why use a preservative?
Mechanisms of rancidity
Storing products in the fridge
If you really want to make products without preservatives...
The importance of preservatives