Avocado oil is pressed from the flesh of Persea gratissima, a fruit tree native to Central America and now cultivated across Mexico, Chile, Peru, South Africa, and Spain. Unlike most plant oils, which are pressed from seeds, avocado oil comes from the fatty pulp surrounding the pit. Spain is among the leading producers of avocado oil in Europe, and the source of the refined avocado oil we use at Eternal Sunday.
Why it works in soap
Avocado oil is exceptionally high in oleic acid, typically running between 60 and 80% of its fatty acid profile. Oleic acid is a monounsaturated fatty acid that saponifies cleanly in cold-process soap, contributing to a mild, conditioning lather and a bar that is gentle on skin. It also brings a meaningful concentration of vitamins A, D, and E, which survive the saponification process to some extent and contribute to the soap's skin-feel.
In cold-process soap formulation, avocado oil is valued for the same reason olive oil is: it produces a conditioning, mild bar rather than a stripping, high-lather one. It pairs well with coconut oil (which provides the lather) and shea or cocoa butter (which provide the hardness), filling a similar role to olive oil but with a slightly lighter feel and faster absorption.
Refined vs. virgin
We use a refined avocado oil, which means it has been processed to remove the deep green pigment and mild grassy scent of unrefined virgin avocado oil. In soap formulation, a refined oil is preferable: the natural pigment of unrefined avocado oil can affect the colour of the finished bar inconsistently, and the scent competes with our essential oil blends. Refined avocado oil gives us a neutral, predictable base that behaves consistently from batch to batch.
The refining process also produces an oil with a higher smoke point and longer shelf life, which is why refined avocado oil is widely used in both food and skincare formulations. The fatty acid profile that makes it effective in soap remains intact after refining.
Food-grade in soap-making
The avocado oil we use is food-grade rather than a cosmetic-specific product. This is common practice in small-batch soap-making and entirely appropriate for the application. Cold-process soap does not require cosmetic-grade carrier oils. The saponification process that converts oils and lye into soap and glycerin is the same regardless of the grade, and food-grade refined avocado oil from a reputable source performs identically to its cosmetic-grade equivalent in the finished bar.
In our products
Avocado oil appears in our cold-process soaps, where it contributes conditioning properties and a mild, gentle lather. It works alongside olive oil, coconut oil, shea butter, and castor oil to create bars that cleanse effectively without stripping the skin of its natural moisture.
