A natural detergent – soapnuts

First published October 2007, last updated May 2010.

Soapnuts, or soap berries, have been used as a natural detergent for centuries.

Soapnuts come from the fruit of the trees of the sapindus genus, from the family Sapindacea. There are around a dozen species; native to India, China, Southern Asia, parts of north and central America. The one most widely used for its detergent attributes is Sapindus mukorossi, known simply as the Soap Nut Tree or Chinese Soapberry.

Soap nuts are a small yellow-brown fruit around just under a half to just over three-quarters an inch in diameter; containing a black seed. The shells contain a substance called saponin, usually present in quantities of around 10-15%. Saponin dissolves in water to form suds and can dissolve fats and oils and help to lift grime. Soapnuts are also suitable for use in greywater and blackwater recycling systems.

Clothes washing

A few shells in a cotton bag or just 2-3 teaspoons of soapnut powder can replace your normal washing detergent and fabric softener. A cotton bag containing a few shells will last for up to 3-4 washes. It appears to work out to be quite a bit cheaper too – you can save up to 50% on normal washing detergent. Soapnuts are fragrance free and if you use the shells instead of powder, they can be added to your compost once their saponin levels have been depleted. Soap nuts are used extensively in some countries for washing woolens and delicates.

Note: While good for normal washing, soapnut isn’t great on really stubborn stains (red wine, grass, blood) from what I’ve read. Warm water is also needed for maximum effectiveness in order to help release the saponin; the higher the temperature, the more saponin is released. 

In the case of cold water washing, you may need more soapnuts or probably a better way to go is to soak the bag with the nuts in a bit of hot water for a few minutes and then throw the bag and water in with your wash.

Another great aspect about soap nuts is that they are low sudsing, meaning they are well suited to high-efficiency and front loading washing machines.

Shampoo and body alternative

Note: As with anything new you apply to your skin, it’s always best to test first on a small area first, and if you’re allergic to nuts; play it safe and don’t experiment.

Soapnut powder can be applied directly to your hair and body to replace soap and shampoo. Soap nut is also used to remove head lice. Very little is needed, around a teaspoon of soapnut powder for long hair; but be aware that when used in this way, it won’t lather like ordinary shampoos. 

Washing Dishes

Soapnut powder or shells can be added to a sink of water to provide you with a totally bridgeable and natural dish washing detergent – and it can also be used in dishwashers! A reader mentioned placing 3 half shells in the cutlery basket, which lasts about 3 loads. Using soapnuts works out to be even cheaper than the cheapest dishwashing powder!

Polishing jewelry

Commonly used for polishing jewelry in India and said to be great for silver and gold – add water to soapnut powder to form a paste, apply then buff off.

Garden

A weak solution of soapnut sprayed on plants can help deter pests such as aphids

Washing cars, floors, window etc.

Boil a handful of crushed soapnut shells in 2 cups of water, simmer for 5-10 mins, then strain. You’ll be left with a cleaning liquid concentrate that can be used for washing cars, floors and just about any surface!

Soapnut in medicine

It seems that some folks ingest soapnuts to cure a number of ailments and it’s also used in Ayurvedic medicine as a treatment for eczema and psoriasis. Be sure to consult an alternative therapy professional before using soapnut to treat any medical condition. I noticed all sorts of weird and wonderful potions and concoctions around the web for treating this, that and the other- it’s one thing to use soap nut to wash dishes, quite another to start eating the stuff. Play it safe, don’t do it – I hear they are terribly bitter anyway :).

Soapnuts and fish

Just because something is natural, it doesn’t mean it’s totally harmless. The saponin in soapnuts in large enough quantities can have a toxic to fish. It’s been used for centuries as a way to stun fish in ponds that then float to the surface for easy gathering. Saponin does break down quite readily, so it doesn’t pose a significant environmental threat, but as a precaution, don’t empty buckets of the solution directly into waterways.

Soapnut availability

Soapnut shells and powder available for purchase online in most countries. To find a stockist, type the following into a search engine

soapnut country

… where country is the name of the country in which you live.

I’ve also noticed some soapnuts now carrying the USDA Organic certification.

Cost of soapnut powder and shells.

Prices vary widely and are dependent on country; but as a general guideline, expect to pay around USD$15-$20 a pound for shells (good for up to 300 washes) and around $20 – $25 a pound for the powder; which is just crushed soapnut shells without any additives. You can create your own powder from shells with a coffee grinder or mortar and pestle.

Do you know of other uses for soapnuts not mentioned above?