Beer and castor shampoo bar
A shampoo bar with flat beer as half its liquid and a fifth castor oil for a dense, lasting lather, on olive oil, babassu, cocoa butter and shea. The beer cures it to a light caramel, and clary sage and orange scent it. Use it with an acid rinse.
- Skill
- Intermediate
- Method
- Cold process
- Batch
- 1000 g of oils about 1458 g of batter
- Hands-on
- 1 h 15 min
- Cure
- 6 weeks
- Gel phase
- No keep it cool
What you need
For 1000 g of oils, which fills a 1.5 litre loaf mould. Weigh everything, liquids included.
| Olive Oil · 30.0 % | 300 g | 10.58 oz |
| Babassu Oil · 25.0 % | 250 g | 8.82 oz |
| Castor Oil · 20.0 % | 200 g | 7.05 oz |
| Cocoa Butter · 15.0 % | 150 g | 5.29 oz |
| Shea Butter · 10.0 % | 100 g | 3.53 oz |
| Sodium hydroxide (NaOH) · the lye, 100 % pure | 137.3 g | 4.84 oz |
| Distilled water · for a 33 % lye solution | 140.7 g | 4.96 oz |
| Beer, flattened and boiled · half the liquid, frozen to a slush with the water | 150 g | 5.29 oz |
| Vinegar (5 % acetic acid), for the rinse · in a mug (250 ml) of water, poured through the hair after washing; not part of the soap | 1 tbsp | |
| Clary sage essential oil · 1.5 % of the oils, at trace | 15 g | 0.53 oz |
| Sweet orange essential oil · 1.5 % of the oils, at trace | 15 g | 0.53 oz |
- Superfat
- 5 %
- Temperatures
- Beer lye solution and oils at 30 to 32 °C (86 to 90 °F), no insulation
Method
-
Flatten the beer the day before
Open a 330 ml bottle or can of pale beer and leave it uncovered for 24 hours, then boil it and simmer it for 30 minutes, watching that it doesn't foam over. Let it cool, weigh out 150 g and keep it in the fridge: boiled beer left at room temperature goes mouldy. -
Freeze the liquids to a slush
Stir the 150 g of flat beer into 140.7 g of distilled water in the lye jug and freeze it until it is slushy, checking after an hour and then every 20 minutes. -
Get ready
Put on goggles, gloves and long sleeves, open a window and line a 1.5 litre loaf mould. Weigh 250 g babassu oil, 150 g cocoa butter and 100 g shea butter into the pot, 300 g olive oil and 200 g castor oil into a jug, and 137.3 g sodium hydroxide into a dry container. -
Add the lye to the beer slush
Stand the jug in a bowl of cold water and stir in the sodium hydroxide a quarter at a time, letting each portion dissolve before the next, never the liquid onto the lye. It smells strongly and darkens as the beer's sugars meet the lye; let it cool to 30 to 32 °C (86 to 90 °F). -
Melt the oils
Melt the babassu oil, cocoa butter and shea butter until just clear, stir in the olive and castor oils and let them cool to 30 to 32 °C (86 to 90 °F), no lower, or the butters start to set. -
Mix the essential oils
Weigh 15 g clary sage and 15 g sweet orange essential oil into a small glass and stir them together. -
Blend to light trace
Pour the lye solution into the oils through a sieve and stick blend in short pulses. Castor oil and the beer's sugars both speed trace, so stop at light trace, add the essential oils and blend for a few seconds more. -
Pour and leave it uncovered
Pour into the mould and tap it on the worktop to let air out. Leave it uncovered in a cool room with no towel over it: the beer's sugars heat the loaf. -
Unmould and cut
After 24 to 48 hours, once the loaf is firm, unmould it with gloves on and cut it into bars. -
Cure for four to six weeks
Stand the bars on a rack with air around them for four to six weeks. The beery smell fades as they cure. -
Wash your hair and rinse with acid
Lather the bar into wet hair and rinse well, then pour a mug (250 ml) of water with 1 tablespoon (15 ml) of 5 % vinegar through it, keeping it out of your eyes, and rinse again with water if you like. -
Let the bar dry between washes
Stand it on a draining dish so it stays firm.
Tips
- Babassu is a lauric oil much like coconut, and it is what Cable uses in her beer soap. Coconut oil can take its place weight for weight, but it takes a little more lye, so run the swap through the calculator first.
- Boiling doesn't remove all the alcohol: about a third of it is still there after 30 minutes' simmering. That is fine in soap; the boil is there to get rid of the bubbles, which foam up when the lye goes in.
- Castor oil at 20 % is the top of the usual range for a shampoo bar. Past that, a bar stays soft and tacky however long it cures.
- In hard water, soap leaves a dull, waxy film on hair, and the acid rinse is what lifts it. If your water is very hard, a syndet bar may suit you better.
The oils
| Oil | Share |
|---|---|
| Olive Oil (virgin / refined / olive oil) | 30.0 % |
| Babassu Oil | 25.0 % |
| Castor Oil | 20.0 % |
| Cocoa Butter (Theobroma Oil) | 15.0 % |
| Shea Butter | 10.0 % |
How it is made
| Process | Cold process |
| Alkali | NaOH |
| Superfat | 5 % |
| Water | lye water at 33 % |
| Iodine value | 57 |
| INS | 146 |
Why make it
For people who want to try washing their hair with a bar. A fifth castor oil and a quarter babassu give a dense, lasting lather, bubbly 34 and creamy 40 on our scale, and the beer's sugars add to it, as makers of beer soap have long found. The beer brings no proven benefit to hair; its part is lather, colour and the story. The caveat is real: soap is alkaline, around pH 9 to 10, and a review of shampoo pH found that alkaline products leave the hair surface more negatively charged, which means more friction and frizz. That is why this recipe pairs the bar with an acid rinse, and why it does better in soft water than hard, where soap leaves a dull film. People with very hard water, or with coloured or permed hair, often get on better with a syndet shampoo bar.
Sources
- Pure Soapmaking · Storey Publishing, 2016
- The shampoo pH can affect the hair: myth or reality? · International Journal of Trichology, 2014
- Hardness of Water · US Geological Survey, Water Science School
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 11.9 %
- Myristic acid 4.8 %
- Palmitic acid 10.9 %
- Stearic acid 11.7 %
- Ricinoleic acid 17.7 %
- Oleic acid 35.1 %
- Linoleic acid 6.7 %
- Other 3.5 %
Saturated : unsaturated 41 : 59
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
Shampoo bars: what true soap does to hair
Soap shampoo bars, honestly: what alkaline soap and hard water do to hair, why an acid rinse helps, when a syndet bar is the better choice, and a recipe.
Beer, wine, coffee, tea and juice in soap
Using beer, wine, coffee, tea or juice in place of soap's water: how to prepare each one, add the lye safely, and what the calculator does with the liquid.
Soap in hard water: scum, chelators and rinse
Why soap turns to scum in hard water, how much soap each litre wastes, what a chelator in the bar can and cannot do, and why coconut soap copes best.
Where these proportions come from
Adapted from the beer soap in Kelly Cable's Natural Soap Making Book for Beginners: her olive oil, babassu, cocoa butter and shea butter and her flat-beer method, with beer as half the liquid, but with a fifth of the oils moved to castor oil for a shampoo lather, at the same 5 % superfat.
Formulation adapted from The Natural Soap Making Book for Beginners by Kelly Cable (Althea Press, 2017). The method and notes are ours.