Substitutions
What preservative should I use? How much of it should I add?
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...
Do I need to add a preservative to this recipe? How long will it last?
Short answers: Does it contain water, OR will it come into contact with water, and do you intend to keep it longer than a day or two? Yes, you need...
If I add one water containing ingredient to an otherwise water-free formula, do I need a preservative?
Yes. The inclusion of water always means you need a preservative unless the product is intended for immediate use. You will also need to incorporate an emulsifier...
Do I need to add a preservative to this if I plan on keeping it in the fridge?
Think of unpreserved DIYs that contain water like leftover food. How long would you leave a chili or a soup in your fridge before deeming...
How long will last? What is its shelf life?
Long story short, it’s pretty impossible to give you an accurate answer to this, but I’ll try to help you determine a ballpark. Probably at least a...
Preservative Calculator
It is best to include your preservative as part of the original formulation, as a percentage, by weight. This calculator adds the preservative on top...
If I don’t have a broad-spectrum preservative, what can I use instead?
Nothing. Seriously. There is nothing that will replace a true broad-spectrum preservative. If you do not have one, you should buy one, or you should only...
Some common myths & misconceptions about preservatives
Whenever you’ve got water in a product, you need a broad spectrum preservative. Here are some common misconceptions about times when a preservative might not be...
Do I need to add a preservative to my soap?
If you are making your soap properly (that is, without a ridiculously high superfat percentage, and ensuring you’re measuring & calculating correctly)—no. Soap has a...
How will adding - ingredient impact the shelf life of my product?
To start with, there’s two main categories of product when we’re talking shelf life: things that are 100% oil based (lip balms, body butters, salves),...
On “antibacterial” ingredients
There are lots of ingredients out there that are touted to have antibacterial properties. These include things like honey, salt, and lots of essential oils...
Can I use a different preservative than the one you’ve used?
Maybe. Different preservatives have different strengths and weaknesses, and different requirements for success that may or may not be compatible with the formulation. If you...
How do I know my preservative is working?
The two biggest ways you’ll know if your preservative is working are either the test of time (months and years), or a professional microbial challenge...
Why did my formulation spoil?
In the broadest sense, your formulation spoiled because some sort of microbes overcame your preservation system and are now having a party in your project,...