How to make herbal shampoo bars with goat milk, nettles, and essential oils using the cold-process soapmaking method. This is a recipe from the Herbal Academy and includes guidance on how to use shampoo bars without ruining your hair.
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One of the most frequent queries I get from both hobby soapmakers and customers is for shampoo bars. It’s a sensitive subject for me, and I’ll get to why I haven’t shared one of my own yet a little further on. The Herbal Academy has just released a brilliant new book though, Botanical Skin Care Recipe Book, and I’ve asked them if I could share their herbal shampoo bar recipe that you’ll find on page 247. The reason is to share a recipe for those who want to try making soap for hair, but also to fill you in on shampoo bars, syndet bars, and how to use them.
The Herbal Academy shampoo bar follows a standard cold-process recipe. It uses coconut oil, olive oil, and a few other easy-to-source base oils. It also uses a nettle infusion, to regulate oil production and goat’s milk to create a creamy and nourishing bar. A herbal blend of essential oils gives scent and scalp-stimulating properties.
What are Shampoo Bars?
Shampoo bars are a solid cleanser that we lather and use to clean our hair. However, the popular shampoo bars that most people have experience with are not real soap. They’re called syndet bars and they are formulated to clean our hair in the same way as liquid shampoo. That means that they’re pH balanced to better match our bodies’ pH. Whether a skincare product is acidic or alkaline matters because if it’s even a little bit off it can disrupt our skin’s acid mantle. What that can mean is irritation and damage to our skin, scalp, and hair.
Real soap has a pH of between 9-11 and is much more alkaline than our skin and hair’s pH of 5-6. That’s why some people find soap controversial on skin. My feeling is that our pores constantly secrete oil, human sebum, and it replenishes the acid mantle of our skin. Still, overuse of soap isn’t great as many of us have found on our hands over the past year!
Hair does not secrete oil though and instead relies on the oil from our scalp to create that protective layer. When we wash that oil off regularly, our hair loses its natural conditioner. That’s why we use a conditioning product after using shampoo.
However, the residue of real soap on our hair also leaves an alkaline pH that dries our hair out. It also causes the shingles on each hair shaft to lift up, rather than lay down to form a shield. That’s why many people who have tried using soap as shampoo have the experience of their hair turning into a tangled mess that feels very dry and uncomfortable. The longer or more color/chemically-treated, your hair is, the worse the problem will be.
Syndet bars vs. Soap bars
Syndet (synthetic detergent) bars are what most people use and love as shampoo bars. They are made of sodium lauryl sulfate, sodium cocoyl isethionate, cocamidopropyl betaine, sodium coco sulfate, coco glucoside, and/or other surfactants. You’ll find these ingredients mixed with oils and scent and together they work to pull grime away from skin and hair. Your hair feels like it does after using liquid shampoo and it’s scented by the shampoo bars too. Think of syndet bars as solid versions of our more standard liquid shampoos.
True shampoo bars (like this one) are synthetic pH-balanced cleansing bars. They need less packaging so can be zero-waste, but they are not 100% natural and they are certainly not real soap. Shampoo bars made in the cold-process method, like the below herbal shampoo bar recipe, are much different and need more pre-and-post prep work to avoid them harming your hair. It’s a conundrum for those of us wanting to avoid synthetics!
How to use a Homemade Shampoo Bar
Cold-process shampoo bars aren’t ideal for hair care. Still, there are people who say they have a good experience with them. There are a few reasons for why this may be. Their hair may be short, their skin and hair is naturally oily, and/or they are using products immediately after washing that lower the hair’s pH. They may also be applying something else, such as conditioner or hair oil, that adds back protective oil and moisture.
To avoid damaged hair by using a homemade shampoo bar you can rinse your hair with a dilution of apple cider vinegar immediately after washing it. The usual dilution is 1 tsp apple cider vinegar to 1 cup water. If you use this herbal shampoo bar recipe, I’d suggest that you try it too. Since the soap recipe uses nettles, I’d say that adding the ACV to a cup of warm nettle tea would be the way to go too. It won’t sting, so don’t worry. The idea is that the cider vinegar balances the hair’s pH back to something a bit more acidic. Using a nourishing conditioner after this can soften and replenish the hair even more.
Why am I sharing this Herbal Shampoo Bar
Many people do use soap bars to wash their hair. It’s really hit or miss as to whether your hair will respond well to them, though. If you have color-treated, permed, or curly hair, I do not recommend using soap as shampoo. I know that some people with long hair do use soap as shampoo by putting their hair in a ponytail and trying to wash only the roots. However, soap and that ACV rinse can damage hair in the long run. Longer hair suffers more than shorter since it’s exposed to the regime for longer.
So why am I sharing this recipe? I’m sharing it because there are some people who really do have favorable experiences with soap as shampoo. When the Herbal Academy sent me their Botanical Skincare Recipe Book, I naturally looked through the soap recipes at the end and the shampoo bar caught my eye.
One of the positive things about the Herbal Academy’s shampoo bar recipe is that it has a high superfat. Usually, soap bars have about 5-8% extra oil added in that stays free-floating in the bar. It doesn’t turn into soap and instead leaves adds to a conditioning and gentle bar of soap. This herbal shampoo bar recipe used an incredible almost 16% superfat. What this does is create a milder bar that may leave a bit of that conditioning oil behind.
Herbal Shampoo Bar Recipe
This herbal shampoo bar recipe is a smaller batch size than the one in the book. It’s the perfect size for those wanting to give soap-based shampoo bars a whirl. If you want to make a larger batch, use the toggle in the recipe card to scale the recipe up. The bars are light brown and hard after their cure time.
In addition to the original recipe instructions, I’ve left a few suggestions that I think will help you. One comment pertains to the amount of liquid used to make the lye solution (called the lye water). The other is that I don’t recommend that you insulate the soap after you pour it into molds. More on that below.
The bars also have a very high superfat. It also contributes towards initially soft and sticky bars and reduces the lather. It will still clean though and hopefully, leave some of that conditioning superfat on your hair. You can also use this herbal shampoo bar recipe to create a very mild cleansing bar for your skin.
Nettle & Goat Milk Shampoo Bar Recipe
- Stainless steel pan for melting the oils
- A large bowl for measuring the liquid oils into
- 173 g Distilled water (6.1 oz )
- 2/3 cup fresh nettles (or 1/3 cup dried)
Goat Milk Slurry*
- 133 g Nettle tea (4.69 oz)
- 38 g Goat milk (1.3 oz)
To Make the Lye solution
- 57 g Sodium hydroxide (2 oz)
- Prepare mold, lining it if necessary.
- Heat distilled water to boiling point. Remove from heat and add fresh or dried nettle. Allow to cool.
- Remove nettle, or strain out powdered nettle.
Make the Goat Milk Slurry
- Measure out the nettle tea and goat milk and put it in the freezer until slushy and almost frozen. Tanya's notes: this took around an hour for me. I checked every fifteen minutes and swirled the liquid around each time so that the mixture would be an even slushy texture.
Melt the Oils
- Weight and combine the olive oil, coconut oil, castor oil, avocado oil, and shea butter in a large stainless steel pot. Heat until melted and cool to 90-110 degrees F (32-43 degrees C). Tanya's notes: it's easier to melt the solid oils in the pan then add the liquid oils after the solid oils are melted. Doing this helps keep the overall oil temperature lower.
Make the Lye Water
- Weigh lye. Go outside, and with proper safety gear on, add lye to the goat milk and nettle water mixture [the slurry] stirring until dissolved. 90-110 degrees F (32-43 degrees C).Tanya's notes: I cooled my oils and lye water to 100F (38C) before mixing them together. Also, proper safety gear includes goggles, rubber gloves, an apron, and closed-toe shoes.
Make the Shampoo Bars
- After oils and lye water are cooled, pour lye water into oils and blend with an immersion blender on and off until the mixture reaches light trace. Tanya's notes: I recommend pouring the lye water through a sieve to catch any undissolved bits of lye. Also, this recipe takes a very long time to come to trace, at almost five minutes. If you've never made soap before, please read the full instructions in my eco-friendly soap recipe for a full explanation of the way you use an immersion blender and what trace is. That recipe includes a video for you to watch too.
- Add essential oils and blend until incorporated.Tanya's notes: blend means to stir gently with your spatula. Do not use the immersion blender here.
- Pour into mold, cover, and insulate lightly for 24 hours. Goat milk can cause soap to overheat so watch for any bubbling or splitting. If gel becomes too dark, remove cover.Tanya's notes: I poured this soap into a 1-lb silicone soap mold and insulated it soap as instructed. I did this using a closed shoebox and a towel wrapped around the mold to keep the soap warm. A small plate placed over the top of the soap mold kept the towel from touching the soap. The shoebox helps the soap to fully gel and turn brown. If you leave this milk-based soap only 'lightly' covered with a tea towel, the center of the block would likely gel and the outsides wouldn't. That would leave a dark circular center called partial gel.
- Tanya's Additional Notes: Though I followed the instructions for the recipe, I personally would not recommend insulating soap made with goat milk or any other milk. It can scorch and turn brown since the sugars in milk can heat up (and overheat!) the soap even after you pour it into molds. Instead, soap at a cool temperature, pour the soap batter into the mold(s), and leave it uncovered on the counter. Alternatively, put the soap in the refrigerator to keep the temperature down and the bars white, as I share in my own goat milk soap recipe. I also poured some of this soap into small molds and refrigerated it so that you can see the color difference. The bar that looks a little squished is one that I tried removing from the mold after two days. The other is one that I froze solid before removing from the mold.
- Remove from mold, cut, and cure for 4-6 weeks.Tanya's notes: I removed the block of soap and measured it into six bars 3/4" bars and cut them with a stainless steel kitchen knife. When doing this, make sure that you wear gloves when handling the soap within 48 hours of making it. During this time, the soap will still contain a small amount of lye and can irritate your skin.
- Tanya's additional notes: you will very likely have trouble removing this soap from your mold(s). Due to the full-water amount and high superfat the soap is soft and very sticky after 24 hours, and even after several days. If you run into this issue, you can either wait a week or two to get the soap out or put your soap molds in the freezer until the soap is completely frozen. The soap will then pop out of the molds like ice-cubes and will not affect the soap or its qualities.
Curing and storing your Shampoo Bars
- The Herbal Academy instructions end here, but I'd like to give you a little more guidance on what to do next. Soap needs at least a month if not two months to be ready to use. With this recipe, I'd advise a 6-8 week cure time, just to ensure that excess water evaporates out, the lye and oils complete saponification, and most importantly, soap crystals have a chance to fully form. Because this soap is high in coconut oil, you will need that time for the soap to become mild enough to use. Here are full instructions on how to cure soap.
- Once made, your soap will have a shelf-life of up to two years. Check the oil bottles that you're using though — the closest best-by date is the best-by date of your soap. Store cold-process soap out of direct sunlight but not in a sealed container. Soap sealed in tupperware will sweat and the excess oil in the recipe (the superfat) may go rancid.
- When using soap bars as shampoo, ensure that you finish with an acid rinse to help neutralize the pH of your hair. Follow up with a conditioner of your choice. Leaving these steps out can result in your being very unhappy with the texture of your hair.
Botanical Soapmaking Inspiration
If you’d like even more natural skincare and soapmaking inspiration, I’d recommend the Botanical Skincare Recipe Book. It includes lots of lovely recipes that you can make at home, including lotions, bath bombs, and more. Though the recipes are brief, there’s information at the beginning on the principles of making salves, skincare, and soap. For even more inspiration here on Lovely Greens, check out:
- Natural Chamomile Soap Recipe
- Rosemary & Cambrian Blue Clay Soap Recipe
- Six Ways to Make Herb-Infused Oil for Skincare and Salves
- Homemade Dish Soap for the Zero-Waste Home