Soap That Grows On Trees

+ Are they too good to be true?

I first stumbled across soapberries while living in indigenous Taiwan in 2016. They’re simple: dried berries that lather up when mixed with water. It’s a feature of an organic chemical they contain called saponin, a chemical also found in soybeans, chickpeas, and quinoa. But what makes the soapberry different is that its saponin content is 37%—the highest percentage discovered in a plant so far. Soapberries also have a pH balance of 5.5, the same as human skin. This helps maintain the skin's protective barrier, reducing the risk of irritation and dryness.

Soapberries. Photo by David Eickhoff from Pearl City, Hawaii, USA, licensed under CC BY 2.0

You’d think using it as a sustainable, biodegradable alternative to commercial soap would be a no-brainer. As an evergreen, soapberry trees require minimal inputs. While they take about ten years to bear fruit, they’re a keystone species, providing food and habitat for wildlife and supporting pollinators.

So, I went down a rabbit hole and started looking at the ingredient list of the largest soapberry company in Taiwan. They market themselves as a natural soap company. But it turns out that soapberry is a minor part of their formulation. They just use the extract. The rest of the ingredient list is a pretty standard list of your run-of-the-mill soap ingredients like sodium laureth sulfate, a common surfactant derived from petroleum and palm oil, cocamidopropyl betaine, which was named 2004 ‘Allergen of the Year’ by the American Contact Dermatitis Society, and phenoxyethanol, a synthetic preservative that can cause moderate irritation.

As a long-time eczema sufferer, I'm acutely aware of these ingredients. When I was developing recipes for my cookbook, I developed severe eczema on my hands. In Taiwan, dishwashers aren't standard, and the generic dishwashing soap I bought from Costco wreaked havoc on my fingers.

These days, the only brand I can tolerate and easily get ahold of here in Taiwan is Ecostore from New Zealand. Their soap is free of the harmful ingredients that affect me. If I use generic soap brands, my hands will crack and bleed within hours. My husband calls me a canary in a coal mine.

There are raw soapberry products on the market (oftentimes labeled as soapnuts), but personally, I’ve found them to be a lot of work to use and not as tough on stains and grease. Soapberries are also supposedly more effective when paired with hot water. I guess that’s why the bigger companies supplement soapberry extract with synthetic surfactants.

It is openly acknowledged by the soap nut industry that soap nuts are not as effective on stains as chemical detergents, but they maintain that “based on our experience and countless other people’s opinions from around the world, Sapindus Mukorossi soap nuts are excellent for general laundry needs, multi-purpose cleaning, personal care, and various other uses”. - Reusable Nation

Still, I’m optimistic about the ingredient. I think a more minimalistic formulation with the berry could go a long way. I found this NY-based Taiwanese American-owned soapberry bar brand that looks promising, but they don’t seem active anymore on social media.

A missed opportunity, perhaps? Or are soapberries just another niche, exotic ingredient susceptible to greenwashing? What do you guys think?

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Signed copies of my James Beard-nominated cookbook, Made in Taiwan: Recipes and Stories from the Island Nation, are available at Omnivore Books, Book Larder, and Kitchen Arts.