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Richer bars

Yogurt and lavender bar

Ivory bars of yogurt and lavender soap with softly swirled tops beside a small bowl of plain yogurt and a small unlabelled amber glass bottle on a turmeric yellow backdrop

An olive-rich bar with plain yogurt stirred in at trace and a lavender and clary sage scent. The yogurt never meets the fresh lye, so there is nothing to freeze: the easiest way into milk soap.

Skill
Beginner
Method
Cold process
Batch
1000 g of oils about 1488 g of batter
Hands-on
45 min
Cure
6 weeks
Gel phase
No keep it cool
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What you need

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

Olive Oil · 50.0 % 500 g 17.64 oz
Coconut Oil · 25.0 % 250 g 8.82 oz
Cocoa Butter · 10.0 % 100 g 3.53 oz
Shea Butter · 10.0 % 100 g 3.53 oz
Castor Oil · 5.0 % 50 g 1.76 oz
Sodium hydroxide (NaOH) · the lye, 100 % pure 139.3 g 4.91 oz
Distilled water · for a 36 % lye solution 244.1 g 8.61 oz
Plain whole-milk yogurt · unsweetened, at room temperature; stirred in at light trace 75 g 2.65 oz
Lavender essential oil · 2.5 % of the oils, at trace 25 g 0.88 oz
Clary sage essential oil · 0.5 % of the oils, at trace 5 g 0.18 oz
Superfat
5 %
Temperatures
Lye solution and oils at 30 to 35 °C (86 to 95 °F)

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Method

  1. Make the lye solution

    Put on goggles, gloves and long sleeves and work where the air moves. Sprinkle the sodium hydroxide into the cold distilled water, never the water onto the lye, stir until it clears, and let it cool to 30 to 35 °C (86 to 95 °F).

  2. Bring the yogurt to room temperature

    Weigh the yogurt into a small bowl, stir it smooth and leave it on the bench while you work, so it is not fridge-cold when it goes in.

  3. Melt the oils

    Melt the coconut oil, cocoa butter and shea butter gently, stir in the olive and castor oils, and let them cool to 30 to 35 °C (86 to 95 °F).

  4. Weigh the scent and line the mould

    Weigh the lavender and clary sage essential oils into a small glass and line the mould.

  5. Blend to light trace

    Pour the lye solution into the oils through a sieve and stick blend in short bursts, stirring between them, until the batter looks like thin custard.

  6. Add the yogurt

    Whisk a ladle of batter into the yogurt to loosen it, pour it back into the pot and stick blend for a few seconds, until no white streaks or lumps are left.

  7. Add the essential oils

    Stir in the lavender and clary sage, then give the batter two or three short bursts with the blender.

  8. Pour

    Pour into the mould, tap it on the bench to release air, and swirl the top with the back of a spoon if you like a textured finish.

  9. Keep it cool

    Leave the mould uncovered and unwrapped in a cool room; in a warm kitchen, put it in the fridge for the first night. Heat can turn the yogurt bright yellow and give it an off smell.

  10. Unmould and cut

    Unmould when the loaf is firm, usually after two to three days for a bar this rich in olive oil, letting it reach room temperature first if it was in the fridge, and cut it into bars.

  11. Cure

    Stand the bars on a rack with air around them for six weeks, turning them now and then.

Tips

  • Use ordinary plain, unsweetened yogurt. Greek yogurt carries less water and flavoured yogurt carries sugar, and either one changes the recipe.
  • The yogurt brings 66 g of the recipe's water, so the lye dissolves in a little less water than usual, a solution of about 36 %. Let it cool before you use it.
  • Olive oil makes a slow, forgiving batter, so there is time to add the yogurt and the scent before it thickens: a good first milk soap.

Why make it

An olive-rich, conditioning bar, conditioning 57 and cleansing 17 on our scale, and an easy first milk soap, because the yogurt goes in at trace instead of meeting the hot lye. Milk soaps have long been recognised among makers for their gentleness (Casey Makela), and many people choose them for dry skin. The evidence is thin, and one reason is chemistry: yogurt's lactic acid is neutralised by the lye into sodium lactate, so the bar keeps none of yogurt's acidity, and what the milk mostly adds is a creamier lather and a softer feel. Lavender, softened with clary sage, is one of the best-loved scents in soap. Keep the loaf cool while it sets, or the yogurt can turn yellow and smell off.

Sources

  • Casey Makela, Making Natural Milk Soap · Storey Publishing, 1999

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 12.3 %
  • Myristic acid 4.7 %
  • Palmitic acid 12.2 %
  • Stearic acid 9.8 %
  • Ricinoleic acid 4.4 %
  • Oleic acid 44.8 %
  • Linoleic acid 7.7 %
  • Other 5.1 %

Saturated : unsaturated 42 : 58

Hardness 39 29–54
Cleansing 17 12–22
Conditioning 57 44–69
Bubbly lather 21 14–46
Creamy lather 26 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 Faiola's yogurt soap, an olive and coconut oil base with plain yogurt blended in after the lye rather than into it. We added cocoa and shea butter for a firmer bar and set the water so the lye still dissolves in a solution of about 36 % once the yogurt's share is taken out.

Formulation adapted from Soap Crafting by Anne-Marie Faiola (Storey Publishing, 2013). The method and notes are ours.

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