All soap nuts are not created equal.
Soap nuts are a fruit that comes from a genus of trees and shrubs known as Sapindus. It is their remarkable ability to produce truly all-natural soap (saponin, the natural active ingredient) that makes them very special and unique. Saponin is the ideal natural, organic detergent and cleanser. (When I state “organic”, I am using the term synonymously with natural – from the earth.) However, all soap nuts are not the same. They vary greatly – and the results you receive from them vary accordingly.
As a consumer, you receive soap nuts as dried fruits with their seeds removed (hopefully since they are sold by weight). If they were not dried they would rot, as would any fruit. Think of soap nuts as you would a bag of dried fruit snacks or big dry raisins. They remind me of cherries. They have a very large seed and relatively thin pulp and skin. While fresh off the tree, a small slit and little squeeze will pop the seed out. The pulp and skin are then left to dry in the sun. When made wet again and agitated the saponin is released creating the suds you will see.
However, as an apple is not just an apple, and a grape is not just a grape, a soap nut is not just a soap nut. Do you think a vineyard cares about the type and quality of the grapes they grow? You bet. If all is not right, an entire harvest could become worthless. A grape is probably the most extreme example I can think of to make my point. Such is the beauty of extremes – they make points easy to understand. It is such fundamentals that we will apply to soap nuts. This article is to provide some basics to assist you in becoming a more informed consumer of soap nuts.
As with grapes the varieties run from A to Z. A vineyard is extremely particular regarding the grapes they grow. Different grapes produce different wines. With soap nuts, we don’t need to go to quite that extreme for there are no culinary aspects. The value of a soap nut distills down to one thing – its saponin content (the natural surfactant). A surfactant is what reduces water’s surface tension and allows the water to effectively penetrate fabrics and loosen dirt and grime.
Consider 100% pure saponin as having no variables (other than those caused by the extraction process or method of use). It is what it is, and does what it does. It is the concentration of the saponin contained within the soap nut that we are concerned with. From species to species across the globe, soap nuts vary greatly.
Without going into all the different soap nut species in detail, the Sapindus Mukorossi species are relatively large and contain the most consistently high level of saponin. It is the most prized and highest valued of the many varieties. The Mukorossi soap nut tree grows wild throughout an immense region around the Himalayan Mountains extending from southern China, through Nepal and into northern India. It is called the Chinese soapberry because its true origin is China. It is officially an alien species to the Doon Valley region of the Indian Himalayans where it flourishes today.
Alternately, Sapindus Marginatus as one example (aka the Florida soapberry) is a soap nut, but it does not seem to work as effectively or consistently. The same goes for Sapindus Trifoliatus, a smaller tree from mainly from southern India and Pakistan. They both produce soap nuts, but the quality of the berry is not as consistently high. This appears to be the case for most or possibly all other varieties currently known. There are numerous variables to consider and many data gaps. In this author’s opinion, Mukorossi reigns supreme if you do not want to do a lot of experimentation to get good results.
Most people have no clue as to what a soap nut looks like. The name implies that it looks like a nut. Even those of us who see and use soap nuts routinely are not always able to immediately determine one species from another. For example, a prematurely harvested Mukorossi soap nut would look similar to a mature Trifoliatus soap nut once dried. And as with all things in nature variations are common. From soapberry tree to soapberry tree even of the same species every soap nut is not identical. Size varies, color varies, saponin content varies, etc. And then there are always those mutant soap nuts. I’ve seen some very unusual looking soap nuts. As a former tree farmer, Mother Nature never ceases to have her inconsistencies. Let’s not rule out evolutionary changes and possible cross-pollination for increasing the variables with soap nuts.
Complicating this further, it is impossible without laboratory analysis to determine the soap nut species once in liquid or powder form. Given the increase in popularity of soap nut liquid and powder, it is only reasonable to assume increased usage of the less expensive varieties to produce these soap nut products.
The color of soap nuts naturally changes as they age causing more confusion. This is normal. Mukorossi soap nuts are initially golden in color and change to reddish and ultimately blackish. Color is mainly a gauge of the age of the soap nut. If properly stored, the color will not alter the soap nuts’ effectiveness. However, if improperly stored (either too dry or too wet) they will prematurely show signs of age and may lose saponin content or worse – become contaminated. Although soap nuts are naturally anti-fungal and antimicrobial, they are not bulletproof, so to speak.
Again, this article is to help consumers understand that a soap nut is NOT just a soap nut. As the market evolves we see more variants in the market. Cheap, slimy black mukorossi berries from China have popped up in the past year. They’re purported to be better because of “rich dark” color meaning that they have high saponin levels. Nothing could be further from the facts. Wise consumers need to have a basic understanding of these things. As illustrated clearly in the pictures above, color has nothing to do with saponin content. Never assume a seller knows exactly what they are selling. Never assume they are being wholly honest about their product either. For novices, these are common mistakes. I have seen it many times. In some cases, what was sold was anything except what it was claimed to be. Do your own homework and ask questions. I try to help you ask the right questions.
Sadly, whenever there are data gaps and uninformed consumers, people will step in and take advantage of the situation for personal gain. I hope that everyone who tries soap nuts gets the experience that high quality berries provide. The biggest crime occurring in the soap nut business today is unknowing consumers having unsatisfactory experiences because an uneducated or unscrupulous seller sold the customer an inferior quality product.
My goal is to minimize such experiences from happening.