Surfactants Part 2: Liquid Hand Wash
*Before you read further, please read our introduction to surfactants blog here: A Beginner’s Guide to Surfactants so as to familiarise yourself with the basics first.
Our first recipe using surfactants is an easy and oh-so-handy liquid hand soap! Using minimal and all-natural ingredients, this handwash is good for the hands and doesn’t wash any nasties down the drain. The surfactants used are non-toxic and biodegradable, and the end product is skin-neutral. The best thing about this recipe is you can’t really go wrong with it. Even if your amounts are a little off, don’t worry, it will still function well as a hand wash.
Liquidy handwashes are just that, quite liquid, so which surfactant or surfactant blend do you think we will use in making them? If your answer was decyl glucoside with some cocamidopropyl betaine and an optional supporting surfactant, you are correct. Now that we know our surfactant blend, let’s start to create our recipe.
First let’s practice calculating ASM’s. If you don’t know what this is, or need a refresher, please read A Beginner’s Guide to Surfactants.
Let’s have an ASM of about 10% for our handwash, which is pretty gentle but still sufficient cleaning power. You can make it less if you have very sensitive skin. For the sake of simplicity I’m going to just divide my surfactants down the middle and make each 5.
Decyl glucoside: 5/0.51= 9.8ml (rounding to 10ml)
Cocamidopropyl betaine: 5/0.30= 15.2ml (rounding to 15ml)
You can also put these into percentages. So 10% decyl glucoside and 15% coco betaine; as long as the percentages stay the same you can adjust the amounts of other ingredients to anything according to the quantity of hand wash you need.
Substitutions: if you don’t have decyl glucoside, you can use coco glucoside in its place. Just recalculate the ASM. I wouldn’t sub out any of the coco betaine, although a glucoside even on its own will still clean well.
If you want to add in a secondary supporting surfactant (coco glucoside) you can. Just adjust your ASMs to accommodate it. In my recipe below I haven’t used a secondary surfactant as I don’t think it is really necessary for a basic hand wash.
Now that we have our surfactant blend, we can play around with the other ingredients we want in our hand wash. We will add some vegetable glycerine for moisture, some aloe vera gel for a soothing factor, xanthan gum for thickening and some essential oils. I like sweet vanilla blended with herby rosemary but you can of course choose whichever oil you like best.
Here is our customisable hand wash base:
Basic Liquid Hand Wash Recipe with Rosemary and Vanilla
10ml decyl glucoside
¼ tsp xanthan gum (I like to thicken my hand wash slightly, although you can leave this out, it will just be very liquid so you may want to use a spritzer bottle rather)
100ml distilled water, or hydrosol of your choice
2 tsp vegetable glycerine
1 T aloe vera gel
A small pinch of citric acid in some water for adjusting the pH
Optional: add in 5ml of OliveM 300 for an extra luxurious hand wash.
Blend the decyl glucoside and coco betaine together. In a separate container, blend the xanthan gum if using, with the vegetable glycerine. Then drizzle in the water bit by bit, blending with an immersion/stick blender as you go. Add in the aloe vera gel and preservative and blend to incorporate. Now add the surfactant blend into your liquid phase and stir gently but well to combine everything fully. Add in your essential oils and the carrier oil and test the pH using test strips. You’re looking for a skin-neutral pH of around 5; a pH of 5.5 is ideal. If necessary, adjust the pH down by adding in a tiny amount of your citric acid solution, then pour into a pump bottle.I love that the scent of this hand wash really lingers on my skin.
The following recipe variation contains more vegetable glycerine and doesn't use aloe vera or xanthan gum. It is a fresh, citrus scented gel that will go well in any bathroom.
Citrus Hand Wash
9% or 22.5ml coco glucoside
10% or 25ml cocamidopropyl betaine
10% or 25ml vegetable glycerine
68% or 170ml water, or substitute some of the water for a floral water such as orange hydrosol
5ml OliveM 300 (optional but recommended)
Weigh out the surfactants and stir gently to blend them. Then stir in the veg glycerine, then the water in a few additions, stirring in between each.
Dollop out some of the handwash into another bowl and stir in your essential oils and preservative, then add it all back into the main mixture. This just helps it combine better. If you are using the OliveM 300, add this in now too.
Test the pH, and if necessary adjust it down by adding a small amount of citric acid solution (a few citric acid crystals in some water). If you want to thicken the hand wash you can add in a pinch of xanthan gum or some salt and blend well with a stick/immersion blender. Decant into a pump bottle and enjoy!
A little goes a really long way with these hand washes, making them economical as well as ecofriendly! Go wild and make a different scented hand wash for every sink in your home.