Are Soap Nuts Safe for Cloth Diapers? (The Truth!)


If you’re interested in using cloth diapers, chances are you’re very interested in eco-friendly and chemical-free cleaning products too. So, it’s no wonder that soap nuts have crossed your path and now you’re wondering if they might be perfect for cleaning your cloth diapers.

Well, I’m glad you landed here because I have some important information to share with you about using soap nuts to clean cloth diapers, but first, let’s make sure we’re talking about the same thing.

What are Soap Nuts?

Soap nuts, sometimes called eco nuts, are actually the dried shells (or husks) from the soapberry nut, which come from the Sapindus mukorossi tree. These unique species of trees are found in both the eastern and western hemispheres but are native to the tropical conditions of India and Nepal.

Even though they are called nuts, soap nuts actually dried berries, making them a safe option for people with nut allergies. Soap nuts are considered totally safe and hypoallergenic which makes them seem perfect for anyone looking for cleaning products free of man-made chemicals and safe for sensitive skin.

How Do Soap Nuts Work?

Nuts or berries, the fact that people are using something unprocessed and directly from a tree to wash their laundry seems too easy. It seems like there should be another step in there somewhere!

So, how do soap nuts work? The shell of a soap nut absorbs water and saponin is released. Saponins, also sometimes referred to as triterpene glycosides, are bitter-tasting usually toxic plant chemicals that have a sudsy, soapy quality when agitated in water. (Source)

How Do You Use Soap Nuts as a Laundry Soap?

Though they produce suds when agitated in water, for laundry, they’re often prepared as liquid concentrate by boiling them to release as much of the saponin as possible. The resulting sudsy water is used as the basis for liquid laundry detergent and other washing products.

Can You Use Soap Nuts for Cloth Diapers?

So, this is all fine and good, but if you’re far along in your cloth diaper research, you’ll know that since cloth diapers contain so many layers, of so many fabrics, and are soaked in human waste, they need strong cleaning ingredients to be successfully cleaned.

So, can you use soap nuts to wash your cloth diapers? No. Unfortunately, the suds created by soap nuts are not nearly strong enough to clean cloth diapers, which are the dirtiest, most complex loads of laundry you will ever wash. To successfully clean a cloth diaper, especially in a modern, low-water washing machine, you need to use a laundry detergent that has surfactants in it.

I will explain the why below, but if you’re in a hurry and just want to know what detergents will work, check out my full post on how to choose a good cloth diaper detergent here. In that post, I do give you some plant-based and sensitive skin recommendations as well if those are the main reasons you’re attracted to solutions like soap nuts.

The Problem with Soap Nuts for Cloth Diapering

I often wrongly speak about soap nuts and homemade “detergents” (which are actually soaps) together when explaining the ineffectiveness of detergent alternatives, but since you’ve followed me this far down the article I know you may just be interested to hear the nuance between the two.

First, let’s establish what soaps and soap nuts are not: detergents.

Detergent

Modern detergents can be formulated to include all sorts of ingredients for specific cleaning purposes. Perhaps the most common and versatile of these ingredients are surfactants (surface active agents) (Source). Surfactants are the most important ingredient in our discussion of getting cloth diapers clean.

Surfactants created synthetically (either from petroleum or from natural sources) for detergents are formulated to trap soil and suspend it in the water, which allows it to easily rinse away, carrying the soil with it. This is why modern washing machines can use so little water. Modern washing machines are made to be used with modern detergents that can clean very heavily soiled garments with minimal water and minimal agitation.

Soap

Soaps, including the ones used as ingredients in homemade laundry soaps, are often made using fats, such as olive oils, combined with lye.

Soaps “clean” things by wrapping soil molecules in themselves, creating a bubble around it. But to rinse that soap bubble away, you need A LOT of water and a lot of friction.

Rinsing soap away is easy to do on a nonporous surface that you can scrub, like your hands, but fabrics with all kinds of porous textures need a ridiculous amount of effort and water. Back when it was great-grandma at her washboard with buckets and buckets of water, this worked, but as we now know modern washing machines are made to use as little water as possible, and as little energy as possible.

Without proper water and agitation, soap creates a film when mixed with dirt that’s just left on the diapers.

In hard water, soaps also form a scum that deposits on everything. 

The film and scum left behind by soaps builds up on diapers, holding onto bacteria and ammonia, which soon leads to smells and painful rashes. It’s basically a cloth diapering nightmare.

Soap Nuts

A soap nut, or rather the saponin it produces, is neither a soap or a detergent.

As we’ve learned, detergents are so good because they have surfactants. Sapopins are often said to be surfactants, but aren’t really.

Surfactants are compounds, usually extracted from petrochemicals, which form natural layers between different liquids or gases. Saponins are naturally occurring plant compounds that are known to work as surfactants, but their properties as foam and emulsion stabilizers is not well understood (Source).

What is now understood is that in order to work, the surfactant properties in soap nuts need heat.

In this 2011 study of sapopins as surfactants, they found that, “Good washing performance of soap nut shells evaluated through primary effect was obtained especially at 90 °C.”

Unfortunately, 90 °C is the common temperature of the sanitize cycle in many washing machines, which we know very well would quickly damage the plastics in many cloth diapers (PUL, snaps, Velcro, and synthetic fabrics).

Of course, even if you were to ignore the temperature warnings, the actual real-world effectiveness of soap nuts has been proven time and time again to be dismal, even on simple, single-layer cotton clothing.

The Proof is in the Testing: The Ineffectiveness of Soap Nuts In Studies

The Choice tested soap nuts in both a top and front load washing machine in cold water, and found that they were no more effective than washing your clothing in plain water. The website’s review of soap nuts gave them an overall score of 42%.

This 2013 study also found that soap nuts (as well as soapwort, and two kinds of wash-balls) don’t show a significant difference in cleaning performance compared to the treatment in pure water. This study used both 30°C and 60°C washing tests.

What Happens if You DO Use a Natural Soap (Like Soap Nuts) to Wash Cloth Diapers Anyway?

Back in 2016, I was in the midst of my own cloth diapering journey and absorbing all of the information I could to one day create this very website. Back then, Eco Nuts, a brand of soap nuts, were just storming onto the scene and everyone was trying them out.

Me being me, I wanted to do a million years of research before laying money down on buying them and the large shipping costs. While I was slowly researching in between feedings, diaper changes and the rest, I witnessed the majority of the cloth diaper community fall in love with soap nuts quickly, and then fall out of love with them just as fast!

Even the big US brand Thrsties had a blog post about soap nuts, and later it was taken down (you can see it on the internet archive here but won’t find it on their website).

Here’s how the love story between soap nuts and cloth diapering parents went, along with what I now understand the problem to be:

Phase One: These are Working Great!

Ninety percent of the time, we use WAY too much detergent in our laundry. We just aren’t taught how to measure out detergent to wash our clothes, and detergent makers don’t make it easy. So, understandably, we throw a full cap in, use an extra glug if things look dirty, and top it off with some fabric softener (a BIG no-no for cloth diapers) when things get stiff and rough to the touch.

Because of this, often the first few weeks to the first few months of using soap nuts as a detergent goes great!

During this honeymoon period, you’re actually rinsing away all of the extra detergent built up on your laundry and inside your washing machine. It’s able to do this thanks to its fantastic surfactants that still work if not overpowered by too much of itself. That long-built-up detergent is finally released and cleans your laundry in the process.

Even better, your laundry is cleaner than has been for a while because all that extra detergent was holding onto dirt and bacteria too. Your clothes feel softer, you no longer need that fabric softener, and you feel great about your decision to go natural and save the earth a bit.

Phase Two: This is Fine, Let’s Just Add this Other Thing.

Once the detergent is rinsed completely away, and this will take different amounts of time depending on your water hardness, things start to get less wonderful. Suddenly your diapers and clothes don’t feel as clean as they should. Smells start to linger.

Usually, some other excuse will be found. Your hard water means that you just need to add some water softener like Borax or Calgon. Or maybe your washer is getting musty so you have to give it a deep clean every week or so now.

Phase Three: Let’s Do a Strip / Reality Hits

After things funk up for a bit, and the smells really start to kick in, or your baby develops a rash, the community would chime in that a strip might be necessary.

If you’re new to the cloth diaper community and have no idea what a cloth diaper strip is, think of it as an emergency deep-clean. You can read more about when and how to strip cloth diapers here.

The strip will produce, dark, nasty, smelly water. And it’s then that it hits you; the soap nuts were not working! At all!

After seeing this scenario play out a million times, I never tried soap nuts for laundry myself. I wish they were effective. Just like you, I REALLY wish there was an alternative, but unfortunately for our modern washers, a modern detergent is necessary, especially for cloth diapers.

To learn more about choosing a cloth diaper detergent that really works, click here.

Ready to Create your Cloth Diaper Wash Routine?

When you’ve landed on a detergent, the next step will be to create your unique wash routine that takes into account what detergent you’ve chosen, your water hardness, your diapers, and your washing machine so that you get clean diapers from day one!

I have information to help you build your unique cloth diaper wash routine step-by-step right here.

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