Why does olive oil soap have so little lather?

Because that is what olive oil does. It produces a low, slick lather rather than a bubbly one, and the trade-off is mildness. Recipes that lather generously usually rely on coconut oil for it.

What is Castile soap?

Traditionally a soap made entirely from olive oil, named after the region in Spain. The name is now used more loosely for vegetable-oil soaps generally.

Is olive oil good for the face?

It is rich and slow to absorb, which some people find suits dry skin and others find too heavy. It is more commonly used on the body. Patch test if you are unsure.

Olive Oil

INCI Olea Europaea (Olive) Fruit Oil

Overview

Pressed from the flesh of the olive rather than its seed, and the oil that makes a soap mild — the whole basis of Castile soap and the gentlest of the everyday oils.

What it is

Olive oil is one of the few culinary oils that comes from the flesh of a fruit rather than a seed or a nut. That difference shows up in the INCI name, which specifies fruit oil, and it is part of why olive oil behaves the way it does.

It is dominated by oleic acid, which typically makes up around three quarters of it. Oleic acid is a long, single-bonded fat that spreads easily and absorbs slowly — the opposite of the short, fast-absorbing fats in coconut oil. Olive also carries a small amount of squalene, a component that occurs naturally in human skin, and the same molecule that becomes squalane once it is stabilised.

Where it comes from and how it’s made

The olive tree has been cultivated around the Mediterranean for thousands of years, and Spain, Italy and Greece still account for most of the world’s supply.

The best-known grades come from mechanical pressing alone. Extra virgin and virgin oil are pressed without heat or solvents, and are graded on acidity and taste.

There is another grade worth being honest about, because it is common in soapmaking. After the first pressing, the pulp and stones left behind still hold oil, and that residue is extracted to produce olive pomace oil. It is a lower grade for eating, but it saponifies well and is widely used in soap. If a maker is using it, the label will say so.

What it does in a formulation

In soap, olive oil is the mild one. A bar made entirely from it is Castile soap, and it is the standard against which gentleness is measured: very low lather, a slick rather than bubbly feel, and a bar that starts soft and becomes extremely hard over a long cure.

That behaviour is also its limitation. Olive alone lathers poorly and takes a long time to become usable, which is why almost every soap recipe balances it against something that hardens and lathers quickly — coconut oil, most often. Once saponified it appears on a label as sodium olivate rather than olive oil.

Outside soap it is a slow, rich oil. It sits on the skin longer than lighter oils, which suits a massage or body oil and can feel heavy in a facial one.

Why Lovebee uses it

Olive oil is the backbone of our soap. It is the oil that decides whether a bar is kind to skin, and everything else in a recipe is balanced around it.

It is also the least fashionable ingredient we use, and we think that is a point in its favour. It has been made into soap for a thousand years, it needs no explanation, and it does its job without needing to be marketed.

Good to know

Slow to absorb compared with lighter oils. That suits a body or massage oil and can feel rich on the face.
Liquid at room temperature, and it may cloud or thicken in a cold room. That is normal and reverses as it warms.
Vegan and entirely plant-derived.
Keeps around eighteen months to two years stored cool and away from light.
Once saponified it is no longer olive oil but sodium olivate, which is why it appears under that name on a bar soap label.

Common questions

Why does olive oil soap have so little lather?: Because that is what olive oil does. It produces a low, slick lather rather than a bubbly one, and the trade-off is mildness. Recipes that lather generously usually rely on coconut oil for it.
What is Castile soap?: Traditionally a soap made entirely from olive oil, named after the region in Spain. The name is now used more loosely for vegetable-oil soaps generally.
Is olive oil good for the face?: It is rich and slow to absorb, which some people find suits dry skin and others find too heavy. It is more commonly used on the body. Patch test if you are unsure.