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Facial bars

Charcoal and tea tree facial bar

Three slate grey bars of charcoal facial soap beside a dish of black charcoal powder and a sprig of tea tree on a golden yellow backdrop

A firm, mild face bar of tallow, olive and argan oil, coloured slate grey with activated charcoal and lightly scented with tea tree and lavender. Coconut is held to a fifth of the oils and the superfat set at 7 % for a gentler wash than an everyday bar.

Skill
Beginner
Method
Cold process
Batch
1000 g of oils about 1436 g of batter
Hands-on
1 h 15 min
Cure
6 weeks
Gel phase
Yes insulate the mould
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What you need

For 1000 g of oils, which fills a 1.5 litre loaf mould. Weigh everything, liquids included.

Edible Tallow · 35.0 % 350 g 12.35 oz
Olive Oil · 30.0 % 300 g 10.58 oz
Coconut Oil · 20.0 % 200 g 7.05 oz
Argan Oil · 10.0 % 100 g 3.53 oz
Castor Oil · 5.0 % 50 g 1.76 oz
Sodium hydroxide (NaOH) · the lye, 100 % pure 136.0 g 4.80 oz
Distilled water · 260 g for a 34 % lye solution, 16 g set aside 276.2 g 9.74 oz
Activated charcoal · 0.75 tsp, stirred into 1 tbsp of the recipe's olive oil 1.7 g 0.06 oz
Kaolin clay · 2 tsp, stirred into 16 g of water held back from the recipe's water 5.5 g 0.19 oz
Tea tree essential oil · 1.2 % of the oils, at trace 12 g 0.42 oz
Lavender essential oil · 0.5 % of the oils, at trace 5 g 0.18 oz
Superfat
7 %
Temperatures
Oils and lye solution each at 38 to 43 °C (100 to 110 °F)

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Method

  1. Get ready

    Open a window, put on splash goggles, nitrile gloves and long sleeves, and line or set out a 1.5 litre loaf mould. Add a dust mask while you measure the charcoal and clay: both are fine powders that float and settle everywhere.

  2. Weigh everything

    Weigh 350 g tallow and 200 g coconut oil into the pot, and 300 g olive oil, 100 g argan oil and 50 g castor oil into a jug. Weigh 276.2 g distilled water into the lye jug and pour 16 g of it into a small cup for the clay, then weigh 136.0 g sodium hydroxide last, into a dry container.

  3. Make the lye solution

    At an open window or under the extractor fan, pour the sodium hydroxide slowly into the water in the lye jug, never the water onto the lye, and stir until clear. Keep your face out of the vapour and leave the jug to cool, labelled and out of reach.

  4. Disperse the charcoal and clay

    Stir ¾ tsp (1.7 g) activated charcoal into 1 tbsp (about 14 g) of olive oil taken from the jug until no dry specks remain. Stir 2 tsp (5.5 g) kaolin clay into the 16 g of held-back water to a smooth, thin slurry.

  5. Melt the fats

    Melt the tallow and coconut oil on the lowest heat, then stir in the rest of the olive oil and the argan and castor oils. Let the oils and the lye solution each come to 38 to 43 °C (100 to 110 °F).

  6. Blend to light trace

    Pour the lye solution into the oils down the shaft of the stick blender, then pulse for a few seconds at a time, stirring between pulses. Stop at light trace, when the batter looks like thin custard and a drizzle leaves a faint line that sinks back within seconds.

  7. Add the clay, charcoal and scent

    Whisk in the clay slurry, then the charcoal oil, then 12 g tea tree and 5 g lavender essential oil. Pulse two or three times, just until the colour is even and no grey streaks remain; clay thickens the batter, so move on promptly.

  8. Pour and insulate

    Pour into the mould, scraping the pot clean, and tap the mould on the worktop to bring up air bubbles. Cover it and wrap it in a towel so the whole loaf gels, which gives an even, deep grey.

  9. Clean up

    With your gloves still on, wipe the batter off the pot and tools with paper towels into the bin, then wash everything in hot soapy water. Charcoal smears on worktops, so wipe spills while they are wet.

  10. Unmould and cut

    After 24 to 48 hours, when the loaf is firm to a pressed finger, put your gloves back on, unmould it and cut it into bars about 2.5 cm (1 in) thick.

  11. Cure

    Stand the bars on edge on a rack with air around them, out of the sun, for six weeks, turning them every few days.

Tips

  • The lather can look pale grey: that is charcoal released from the bar, and it rinses off skin and basins. Keep to the dose given, because more charcoal makes a greyer lather that can mark pale washcloths.
  • Buy tea tree oil in small bottles and keep it cool and tightly closed. Old, oxidised tea tree oil is more likely to irritate skin than fresh. At 1.2 % of the oils it is under 1 % of the bar, the most the EU's safety committee judges safe in a face wash, so don't raise it.
  • If the centre of the cut bars is darker than the edges, the loaf only partly gelled. It is purely cosmetic; next time wrap the mould in a second towel or stand it somewhere warmer.

Why make it

A firm, mild face bar: tallow and olive oil with coconut held to a fifth and a 7 % superfat, cleansing 15 and conditioning 54 on our scale, so it washes without the tight feel of a coconut-heavy bar. Tea tree oil, distilled from an Australian Melaleuca whose leaves have a long history of use there, has a sharp, clean smell many people like in a face wash. The laboratory and clinical work on it concerns the oil itself, usually stronger and left on the skin; a soap that is rinsed off is not a medicine and makes no claim to be one. Charcoal is sold on a deep-cleaning reputation borrowed from water filters, but in a bar rinsed off in a minute it mainly colours the soap. The caveat: tea tree can sensitise skin, more so once oxidised, and the EU's safety committee judges it safe only up to 1 % in a face wash; this bar stays below that.

Sources

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 5.2 %
  • Palmitic acid 16.1 %
  • Stearic acid 10.0 %
  • Ricinoleic acid 4.4 %
  • Oleic acid 40.1 %
  • Linoleic acid 8.6 %
  • Other 5.2 %

Saturated : unsaturated 44 : 56

Hardness 41 29–54
Cleansing 15 12–22
Conditioning 54 44–69
Bubbly lather 19 14–46
Creamy lather 31 16–48

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.

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Where these proportions come from

Adapted from Kelly Cable's charcoal and tea tree soap: her tallow, olive, coconut and argan blend, with coconut cut from a quarter to a fifth and castor oil added in its place for a milder face bar with a steadier lather, the superfat set at 7 %, and a little kaolin clay for slip.

Formulation adapted from The Natural Soap Making Book for Beginners by Kelly Cable (Althea Press, 2017). The method and notes are ours.

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