This week's Dollar Stretcher newsletter included an article on "A Natural and Frugal Laundry Alternative." The words "natural and frugal" caught my attention, so I read on and found that the product being discussed was something called "soap nuts," also called soap berries or wash nuts. According to the distributor, NaturOli, these are the dried hulls of the soapberry fruit, which contain natural saponins, foaming compounds that work just like soap. To wash your clothes with soap nuts, you just put a handful (four or five "nuts") into a little mesh bag and throw it into a hot-water wash. The same nuts can be reused four or five times, and when they start to turn grey or mushy, you can just throw them on the compost pile.
On the face of it, these sound like the most ecofrugal laundry product you can imagine. They're natural and biodegradable, and the article claims they contain "no harmful chemicals or perfumes." They also produce no packaging waste; the muslin bag is reusable, and the nuts themselves can be composted. But what about their cost? The article says that a pound of soap nuts costs $19 at Amazon, but it doesn't say how many nuts are in a pound, so it's impossible to figure out the actual cost per load. The article provides lots of detail about how well the soap nuts clean clothes and how easy they are to use, but the only mention of their cost-effectiveness is an offhand remark about how the soap nuts "could potentially save me money, too!" Considering that the Dollar Stretcher is supposed to be all about "living better for less," this seemed like a pretty big oversight.
So I started digging around to see if I could find any hard numbers on how cost-effective these soap nuts are compared with regular laundry detergents. I checked the comments on Amazon.com and found one enthusiastic review from an owner who carefully tracked her usage to see how long the nuts lasted. She concluded that they used 5.8 ounces of nuts to wash 68 loads of laundry; at $49.95 for a 4-pound package, she found, this "works out to a cost of $.07 per load!" That exclamation point suggests that she considers this a fantastic price, but my own calculations show that our Purex detergent (bought on sale, with coupons, and used much more sparingly than the bottle recommends) actually costs us between 2 and 3 cents per load. That makes 7-cents-a-load soap nuts look a lot less impressive by comparison.
Of course, it's entirely possible that my $1.25 bottle of Purex isn't getting our clothes nearly as clean as the soap nuts would. The Dollar Stretcher reviewer praises the soap nuts' cleaning performance to the skies, saying they removed mud and food stains with ease and left the clothes smelling "clean but not fake, perfume-y clean." She concedes that they weren't quite up to the task of removing a tea stain from a towel, so pre-treatment might still be necessary for "some types of really icky stains." The majority of users on Amazon.com heap praise on the soap nuts as well, saying they do a great job with everything from cloth diapers to grungy work clothes (even those worn for really messy jobs like painting or auto repair). Most users report their clothes come out fresh-smelling and soft, with no need for a separate fabric softener. Only a few reviewers complain that the nuts can't handle tough stains or odors.
Soap nuts also offer some health and environmental benefits over plain old laundry detergent. Various reviewers on Amazon note that soap nuts are compostable, cruelty-free, and hypoallergenic. One user who is allergic to coconut says these are the only decent laundry product she's ever found that contains no coconut derivatives; others say it has cleared up skin problems like eczema that are exacerbated by most detergents. Users also like the fact that these are a natural product, free of the synthetic chemicals in traditional detergent (which one user blames for "cancer, respiratory and skin irritation, and central nervous system damage").
However, these benefits come with an environmental downside: the berries have to be imported from the "pristine Himalayans of India" [sic], so transporting them must require a fair amount of fuel and produce a fair amount of greenhouse gas. On top of that, this natural product isn't generally sold in stores, so buying it probably means ordering online and having it shipped from the processing plant here in the U.S. Of course, as this Worldwatch Institute article on "food miles" points out, simply calculating miles to market isn't a very good way to measure a product's environmental impact, and the fact that these soap nuts have been shipped thousands of miles doesn't necessarily negate their green claims. But it does take at least a bit of the shine off them.
Another problem with the soap nuts, in terms of sustainability, is that they work best when used in hot water. According to the Dollar Stretcher article, using them this way is incredibly simple: just put a handful of nuts in the mesh bag and toss it in with the clothes. However, if you wash most of your clothes in cold water—as recommended by the American Council for an Energy-Efficient Economy and most environmental sites—then soap nuts take a bit of extra work. You have to soak the bag of nuts in a cup of very hot water for a few minutes before tossing them into the wash. Some users at Amazon recommend going still further and soaking the nuts for 15 minutes to an hour before washing with them. Obviously, this makes the soap nuts a lot less convenient to use for energy-conscious cold-water washers. (However, to be fair, a couple of users say they don't bother with the pre-soaking step at all and their clothes still come out clean, even in cold.)
So, taking everything into account, how do soap nuts compare to standard laundry detergent? In terms of cleaning power, they seem to be at least equal, and possibly better. They also appear to have the edge in terms of sustainability, with their biodegradability and lack of toxic chemicals outweighing their miles to market. On the other hand, they're less convenient to use in cold water, and switching to hot water for all your washes would probably cancel out all the soap nuts' eco-benefits. But their real fatal flaw is their high cost. At 7 cents per load (a price you can only get by buying in bulk), they may appear to be cheaper than most name-brand detergents, but that's only true if you're paying full price for your detergent and using the full amount. If you habitually use coupon stacking to buy your detergent and then skimp on the amount you use, as we do, you'll pay less than half as much per load as you would with the soap nuts.
Of course, if you have a coconut allergy, or extra-sensitive skin, or your top priority in life is to tread as lightly as possible on the earth, you might consider that money well spent. But if your goal is to save resources of every kind, including your time and your hard-earned cash, then sale-priced detergent is probably a better bet.