Amount 0.5-1% of the total weight
Type: Optiphen ND
Like bar soap, liquid soap has a pH level that doesn’t allow mold to grow. However, it does require distilled water for dilution. You can add a preservative to be extra careful or if you plan to sell it. The same goes for the Bramble Berry liquid soap bases – you can add preservatives to the ones that need to be diluted, but the ready-to-use options are already preserved and don’t need extra.
Amount: 1% of the total weight
Type: Optiphen, Phenonip, or Germaben II
Lotion always needs a preservative because it’s made with water. Without one, the shelf life will only be a few weeks.
This is a simple mixture of butter and oil. Because there’s no water and it will likely be applied to dry skin, don’t worry about a preservative. As always, you can add one if you plan to sell it.