What’s the deal with soap nuts? I love that I can avoid plastic packaging by using them, but what are they actually made of? Are they natural and biodegradable? Or are they just condensed detergent?
Julie, Calgary
Soap nuts are a natural, biodegradable and petroleum-free laundry soap alternative. They grow on trees in Nepal and India, but they’re not nuts; they’re actually a fruit. You might also see them sold as soapberries. The tree itself is from the genus Sapindus. (Think back to biology class.)
Soap nuts contain large amounts of saponins in their shells, which are a natural surfactant. Surfactants are compounds that lower the surface tension of a liquid, and so can be used as detergents or foaming agents. You can find soap nuts in many health food stores, organic grocers or online. All you do is add four or five of them, in a small cloth bag, to a load of dirty laundry. You can reuse that pouch of soap nuts for a few loads.
My favourite solution for eco-friendly laundry soap is making my own liquid version from borax, washing soda and soap granules. See my recipe and complete do-it-yourself video at 
Lindsay Coulter gives you the straight goods on living green. Send your questions to queenofgreen@metronews.ca. For more great tips, visit The David Suzuki Foundation at davidsuzuki.org.
