I Made Soap With Watermelon Juice - Here's What Happened

Added: 2026-05-05

[00:00:00]Summer is coming soon. So, today we're making a soap with watermelon juice and watermelon fragrance oil. We're going to talk about why use juices in soap in the first place, how to safely use juices in soap making, and then we're going to walk through the whole recipe and actually make the watermelon soap. I'm very excited for this. Let's go. And for this recipe, we're going to use 40% olive oil, 29% coconut oil, 25% shea butter, and 6% castor oil. Why are we going to use those oils? First of all, olive oil is high in oleic acid and a bit of linoleic acid. Linoleic acid reacts with sodium hydroxide, it produces sodium oleate that is very conditioning and gentle for the skin.

[00:00:46]And the thing with olive olive oil is that it's also low in linoleic acid. We want low concentrations of linoleic acid in all of our oils because linoleic acid is the main source of dreaded orange spots, otherwise rancidity and oxidation, that basically looks like this. Then, we want 25% 29% coconut oil, and we add coconut oil because coconut oil is high in lauric and myristic acid. And those acids, when they react with sodium hydroxide, they produce sodium laurate and sodium myristate, which are what gives bubbles and cleansingness to your soap. Then, we want creaminess and hardness, and for that we're going to use shea butter. Uh you could also use beef tallow if you want. So, shea butter is high in stearic and palmitic acid, and when they react with sodium hydroxide, they produce substances that give creaminess and structure and hardness to your soap.

[00:01:44]And lastly, we want a substance that gives richness, and for that we need castor oil. Castor oil is high in ricinoleic acid, and ricinoleic acid, when it reacts with sodium hydroxide, it provides thickness and richness to your lather. We want a bit of because if you add a a lot, your soap will feel slightly sticky. Good. Let's go ahead and actually measure the recipe. We're going to use sodium hydroxide as the type of lye because we're making solid soap. If we were to make liquid soap, we would use potassium hydroxide.

[00:02:16]Uh grams, we're going to leave it at 1,000 g.

[00:02:20]Lye concentration, we're going to leave it at 35%, which is very typical.

[00:02:24]Superfat, 5%, that's also very normal.

[00:02:28]And fragrance, we're going to leave it at 40 g per kilo of oils. Then, we're going to go down here and basically find all the oils we just talked about and click the plus button. So, we have shea butter, coconut oil, castor oil, and olive oil, and then I'm going to click view recipe summary and get all the details I need. So, I need to add 139 g of sodium hydroxide in 259 g of water.

[00:02:55]So, always add the lye in the water, never the other way around.

[00:02:59]Then, we'll have to add 250 g of shea butter, 290 g of coconut oil, 60 g of castor oil, and 400 g of olive oil.

[00:03:07]Let's go ahead and actually make this recipe.

[00:03:12]And if you're new here, my name is Perry. I have a master's in biotechnology and a background in chemical engineering, and for the past 5 years I've been working in the biotech industry focusing on skin care molecules, and I'm obsessed with understanding formulation and why things work the way they do. If you want a free soap making recipe PDF that contains a balanced soap recipe with coconut oil, shea butter, olive oil, and castor oil, and it also contains an essential oil blend that is long-lasting, comment I want this and I will send to you as soon as I see your comment. First things first, when you're working with lye solution, always make sure you wear protective gear. Make sure you wear gloves, goggles, you are in a well-ventilated area because lye solution can be very caustic and it can also get very, very hot. And we want to avoid inhaling any of those fumes because that's not good for you. Let's go ahead and prepare our watermelon juice.

[00:04:38]So, why use watermelon juice or any other juice in the first place? So, as you can see here, I like using juices because they usually create a very beautiful color, certain juices. So, you can see here, for example, carrot juice creates this phenomenal yellowish-orange color, and all you have to do is to replace your lye water with juice. And in order to work safely with juices, you can either freeze it completely or cool it down in the fridge. So, I'm going to place this right now in the fridge because juices contain a lot of sugars and they tend to overheat. So, when you add the sodium hydroxide, sodium hydroxide tends to create a lot of heat.

[00:05:25]It's a very, very creates a very exothermic reaction. So, we want to cool down our juice in order to avoid overheating. Now, the thing with some natural colorants and some natural juices is that they tend to degrade. So, watermelon juice, as we will see, has a slight tendency of getting slightly brownish. So, it goes from a pink color to slightly brownish color because saponification happens in a very high pH and high temperature, which is a very harsh environment for certain natural colorants. During those conditions, those natural colors, they tend to degrade. And that's why we're going to boost a bit the color with some stable mica powder, which will give this pinkish color, as we will see later. So, we're going to add 259 g of cold watermelon juice. If you have time to freeze it, this is actually the best option. And now, we're going to go ahead and add 139 g of sodium hydroxide.

[00:06:37]Now, we're going to stir it slightly and take it out in the garden to avoid inhaling any fumes. You can start seeing that the watermelon start change its color now because of the harsh sodium hydroxide environment. And now, we're going to take our solid oils, which is coconut oil and shea butter, 290 g of coconut oil and 250 g of shea butter, and we're going to melt them over a double boiler.

[00:07:06]Let's go.

[00:07:09]Our solid butters, coconut oil and shea butter, have melted down. Let's go ahead now and add our liquid oils, which is olive oil and castor oil. We're adding 400 g of olive oil and 60 g of castor oil.

[00:07:28]And now, we're going to let both our oils and lye solution cool down. We want to mix them at low, similar temperature.

[00:07:38]So, we want to mix them at around 29 to 30° C because we know at this temperature we will have great control over our soap batter. When you're working with high temperatures and you're mixing your oils and lye solution at high temperatures, you risk of having the so-called trace acceleration because high temperature leads to higher trace. When you have higher trace, your soap can solidify so fast that you don't have time to pour it into the mold. So, we want to have good control, and for that we want to work at low, similar temperatures. While we wait, we can dissolve our dyes and also measure our fragrance oil solution.

[00:08:20]So, let's first start by measuring our fragrance oil blend.

[00:08:25]And for that, I'm of course going to use a watermelon fragrance oil.

[00:08:32]Unfortunately, you cannot find natural watermelon scents because these scents are very difficult to create natural.

[00:08:40]All the fruity smells are very difficult to create natural, and that's why you can only find them synthetic. When you buy fragrance oils, always make sure you buy safe fragrance oils that do not contain any phthalates or parabens because those are hormonal disruptors.

[00:08:57]So, I'm adding 25 g of watermelon fragrance, and then I'm adding 15 g of patchouli essential oil, which will act as a base note and make it way more long-lasting. Fragrance oils are already very long-lasting, but I just like to combine natural essential oils with synthetic fragrance oils. In the meantime, we're going to place a bit of distilled water in beaker, just very little, and we're going to dissolve our mica powders.

[00:09:29]So, you want to first When you work with micas, you want to first dissolve them in some water, otherwise they might create clumps.

[00:09:42]And for dissolving them, I like to use a small blender.

[00:09:52]And guys, it's time for the most exciting part. Our oils and lye solution have reached low similar temperatures and now we're going to mix them together.

[00:10:04]Once they reach light trace, we're going to separate them into two batches. We're going to add the colorants, add the fragrance oil blend, and then pour it into the mold. And we are ready to go.

[00:10:19]Let's first add our lye solution inside the oil solution. And I'm using a stick blender to avoid any turbulence.

[00:10:30]I'm basically pouring the lye solution on top of a stick blender to avoid any turbulence.

[00:10:59]Our oils and lye solution, they have emulsified. They have reached light trace, so now it's the right time to basically split the two batches, add the colorants, add the essential oil blend, and then pour it into the mold.

[00:11:25]So, first I'm going to start with this one.

[00:11:30]And I'm also going to add half of the fragrance oil blend.

[00:11:37]Here.

[00:11:42]Then I'm going to go ahead and add the green mix here.

[00:11:53]And also the rest of the fragrance oil here.

[00:11:57]And here we need to work fast because we want to avoid any trace acceleration.

[00:12:24]Now, I want to shake the mold so that the soap butter goes everywhere.

[00:12:35]And then I'm going to tap the mold to remove any trapped air bubbles.

[00:12:40]I'm going to slightly insulate the mold.

[00:12:48]So, 24 hours have gone by and our watermelon juice soap has been sitting in the mold. Now, it's time to remove it from the mold, cut it, and then stamp it. Let's go.

[00:13:15]Now, I'm going to use a plastic membrane to stamp the soap so that I avoid any oxidation from the metal stamp to the oils of my soap.

[00:13:43]So, our soap is ready. It's cut, it's stamped, and now we're going to let it cure for 4 to 6 weeks. It smells amazing.

[00:13:52]If you love the smell of watermelon, then this soap is definitely for you. If you want more soap making recipes like that, but also other types of recipes like shampoo, conditioner bars, hand creams, and so on, I have an ebook that contains all of it and it also contains the method on how not to only copy recipes, but how to design your own recipes based on your own goals. Thank you so much for watching this video and I'll see you guys next time.