Extra Virgin Oil
This is an unrefined oil and the highest quality of olive oil that you can buy. It is made by grinding olives into a paste, then pressing them to extract the oil. There is no heat involved, so is often labelled as cold-pressed. The olive oil has no defects and has a free acidity that is less than or equal to 0.8. This oil often has a green colour, which can affect the colour of your soap batter and make getting the colours you want more of a challenge. This type of olive oil contains less oleic acid
Virgin Olive Oil
This oil has minimal defects and has a free acidity between 0.8 and 2. This oil has a slightly higher level of oleic acid in it.
Regular Olive Oil
This is any cold-pressed oil that doesn’t meet the standards above and so is refined to get rid of impurities, giving the oil a lighter colour. It is then blended with a bit of premium Extra Virgin Olive Oil
Pomace Olive Oil
This oil is extracted from the olive pulp using chemical solvents are the virgin oil has been pressed.
Which Version Of Olive Oil Is The Best For Soap Making?
Soap makers have their own preferences of which type of olive oil to use and where to get it. Personally I buy Virgin or Extra Virgin from my local supermarket, but I make sure there is a lot of time left on the expiry or best before date. I have heard other soap makers complain that their soap goes rancid quickly with store bought olive oil and they get DOS – dreaded orange spots, which are caused by rancidity. and so they only buy from cosmetic suppliers. I have never had this happen to me.
Pomace oil is cheaper, but it is a much darker green colour, which I don’t like and it speeds up trace, so is not so good for swirling.
I recommend trying some comparison batches to see what works well for you.
Fatty Acid Profile For Olive Oil
Lauric – hardness, cleansing, bubbly lather 0%
Myristic – hardness, cleansing, bubbly lather 0%
Palmitic – hardness, stable creamy lather 6-14%
Stearic – hardness, stable lather 3-5%
Ricinoleic – conditioning, moisturizing, stable creamy lather 0%
Oleic – conditioning, moisturising, lather silkiness 63-83%
Linoleic – conditioning, moisturising, lather silkiness 6-14%
Linolenic – conditioning, moisturising, lather silkiness 1%
Using Olive Oil In Your Soap
As you can see from this, olive oil adds conditioning properties and helps give a silky lather, but it doesn’t make a hard bar initially. I usually use around 20-30% in my recipes, unless I am making a Castile soap. The more you use the milder and more gentle your soap will be, but it will be low cleansing with a low lather. It can also be sticky on unmolding and difficult to unmold. Sometimes you have to leave it for as long as week before you can get it out of the mold. You can counteract this by doing a water discount of 10-15% and also using sodium lactate or salt at 1 teaspoon per pound or 450g oils, to help your soap to harden. Be prepared to cure your soap for a long time if it contains high amounts of olive oil. Castile soap is best left to cure for at least 6 months to avoid a slimy bar.
Substituting Other Oils For Olive Oil
I wouldn’t recommend doing this in a recipe that has 100% olive oil in it. Olive oil is the only liquid oil that will be rock hard after curing. All other liquid oils will create a mushy soft bar, that will be hard to unmold and will wash away quickly. You can substitute oils for a bit of the olive oil in a formula that also contains hard oils and butters.