High-olive bastile bar
Three-quarters olive oil, with coconut and castor for the lather pure castile lacks. Unscented and gentle, it traces slowly and wants a long cure, and repays it: at eight weeks it is a hard, mild bar with a fine, creamy lather.
- Skill
- Beginner
- Method
- Cold process
- Batch
- 1000 g of oils about 1388 g of batter
- Hands-on
- 1 hour
- Cure
- 8 weeks
- Gel phase
- Yes insulate the mould
What you need
For 1000 g of oils, which fills a 1.5 litre loaf mould. Weigh everything, liquids included.
| Olive Oil · 75.0 % | 750 g | 26.46 oz |
| Coconut Oil · 20.0 % | 200 g | 7.05 oz |
| Castor Oil · 5.0 % | 50 g | 1.76 oz |
| Sodium hydroxide (NaOH) · the lye, 100 % pure | 135.9 g | 4.79 oz |
| Distilled water · for a 35 % lye solution | 252.3 g | 8.90 oz |
- Superfat
- 6 %
- Temperatures
- Oils and lye solution each between 32 and 43 °C (90 and 110 °F)
Method
-
Get ready
Put on splash goggles, nitrile gloves and long sleeves, open a window or turn on the extractor fan, and keep children and pets out of the room. Set the mould out level where it can stay for three days. -
Weigh the oils
Weigh 200 g coconut oil into the pot, and 750 g olive oil and 50 g castor oil into a jug. -
Make the lye solution
Weigh 252.3 g distilled water into a heat-safe jug and 135.9 g sodium hydroxide into a dry container; that is a little less water than usual, which helps this soft soap set. In a well-ventilated spot, pour the lye slowly into the water, never the water onto the lye, stir until clear and leave it to cool, labelled and out of reach. -
Melt the coconut oil
Melt the coconut oil on low heat, then pour in the olive and castor oils. -
Check the temperatures
Go ahead when the oils are clear and both they and the lye solution are between 32 and 43 °C (90 and 110 °F). -
Combine
Pour the lye solution into the oils down the shaft of the stick blender, tap the blender to let trapped air out, and keep the blade under the surface while it runs. -
Blend patiently to light trace
High-olive batter stays thin for a long time. Pulse and stir, over and over, for ten minutes or more if need be, and don't stop at the first slight thickening: wait until a drizzle leaves a faint line on the surface. -
Pour and insulate
Pour into the mould, tap it on the worktop to raise air bubbles, cover it with a lid or board and wrap it in a towel for a day to keep the warmth in. -
Give it time in the mould
Leave the loaf in the mould for two or three days, until it is firm to a pressed finger; soap this rich in olive oil starts soft. -
Unmould and cut
Unmould it with gloves on and cut it into bars about 2.5 cm (1 in) thick. The cut faces may feel slightly slippery at first, which is normal. -
Cure for eight weeks or more
Stand the bars on edge in a dry, airy room and turn them every week or so. They are ready at eight weeks and keep getting harder and milder for months after that.
Tips
- Keep a bar in use on a draining dish. Olive-rich soap goes soft if it sits in water and firms up again as it dries.
- Extra virgin olive oil gives a greener bar than refined or light olive oil. Our calculator treats them as the same oil, so the lye does not change.
- A white bloom of soda ash is common on slow, high-olive loaves. It is harmless: plane it off with a vegetable peeler once the bars are firm, or leave it.
The oils
| Oil | Share |
|---|---|
| Olive Oil (virgin / refined / olive oil) | 75.0 % |
| Coconut Oil | 20.0 % |
| Castor Oil | 5.0 % |
How it is made
| Process | Cold process |
| Alkali | NaOH |
| Superfat | 6 % |
| Water | lye water at 35 % |
| Iodine value | 69 |
| INS | 133 |
Why make it
For anyone drawn to castile soap but not to its slow, slippery lather. Castile, the olive oil soap of Spain, has a long reputation as the mild soap of choice, and three-quarters olive keeps most of that mildness, cleansing 14 and conditioning 68 on our scale, while coconut and castor add the lather pure olive lacks. Makers often choose a bar like this, unscented, for older skin or anyone who finds soap drying. It is still soap, though: for a baby's bath the NHS suggests plain water or a cleanser made for babies, and for eczema it advises washing with an emollient instead of soap. The catch is patience, a soft loaf that needs days in the mould and a cure of two months or more.
Sources
- Castile olive oil soap · Smith College Museum of Ancient Inventions
- Atopic eczema: treatment · NHS
- Washing and bathing your baby · NHS
What tradition, makers' experience and research say about soaps like this, each labelled for what it is. It is not medical advice, and no soap treats a skin condition: if you have one, ask a doctor or pharmacist.
What the numbers say
- Lauric acid 9.8 %
- Myristic acid 3.8 %
- Palmitic acid 12.2 %
- Stearic acid 2.8 %
- Ricinoleic acid 4.4 %
- Oleic acid 53.5 %
- Linoleic acid 9.8 %
- Other 4.9 %
Saturated : unsaturated 31 : 69
Computed from the fatty acids of the fats above. The bands are what the craft has settled on, not chemistry — a bar outside one is not wrong.
From the guides
All guides
Castile soap: pure olive oil, and why it's worth the wait
What castile soap really is, why pure olive oil traces slowly and starts soft and slippery, how long to cure it, and a recipe with the calculator's numbers.
Curing and storing handmade soap
What curing does to cold process soap and what it doesn't, how long it takes, how to set bars up to cure, how to tell when they're done, and how to store them.
Gel phase: to insulate or keep it cool
What gel phase is, why a loaf turns dark and translucent, how gelled and ungelled bars differ, why partial gel is cosmetic, and how to cause or prevent it.
Guides with this recipe
Where these proportions come from
Adapted from Kelly Cable's castile-style bar, olive and coconut oil at about 78:22: olive held at three-quarters, 5 % castor added for a creamier lather, a 6 % superfat for a gentler bar, and a slightly stronger 35 % lye solution so the slow, soft batter firms up sooner.
Formulation adapted from The Natural Soap Making Book for Beginners by Kelly Cable (Althea Press, 2017). The method and notes are ours.