How to get a swirl effect in melt and pour soap

A lot of soapmakers tell you that you can’t get nice colour effects in melt and pour soap. They are wrong. Today I am going to share some of the colour effects I’ve achieved using swirls and layering techniques in melt and pour soap, and explain how you can do them too. Once you’ve tried it out, you’ll have beautiful soaps crafted artistically, just like in cold process soaps!

What is a swirl?

A swirl is where you have more than one colour in a soap, and usually you would spin it e.g. on a Lazy Susan. What is a Lazy Susan, I hear you ask. A Lazy Susan is one of those plate things that people used to use for Thanksgiving in the 1970s because you can spin it around instead of passing the carrots across the table… which is pretty lazy, hence the name.

A Lazy Susan a bit ugly on the dining table and in this day and age of Instagram and Martha Stewart, people tend to have a nice centrepiece in the middle of the table and just pass the carrots to each other. So people dumped their Lazy Susans in the garage and now you can use it to make soap instead! At least, you can if you are making cold process soap.

It doesn’t work so well in melt and pour. I suspect part of the reason why some cold process soapers look down on melt and pour is because they try to do things the exact same way you would do them in cold process, then they decide it’s the soap that’s the problem when it goes wrong.

There is absolutely a way to get a swirl effect in melt and pour, it’s just you don’t swirl it the same way as you would swirl a cold process soap!

How do you swirl in melt and pour?

To get a swirl effect, I use mica powder colours. I love these because they are available in vivid shades. They have a nice shimmer when you use them in high concentrations. Best of all, they show up really well in melt and pour soap. Colourants have to work extra hard in white melt and pour because, as you’ll know if you have ever done cold process, soap isn’t naturally white. The white colour comes from the addition of titanium dioxide, which can nix your other colour choices, especially if you want natural colours. Clays etc struggle in white melt and pour soap. Mica is a natural mineral so it’s a great all-rounder.

Melt your soap and split it into two separate jugs.

In a separate jug, mix your mica with a little rubbing alcohol (if you have no alcohol, you can put the mica directly into one of the jugs of melted soap as this will dissolve in melt and pour, but for colour effects, you get more control over the outcome if you mix the colour up separately because then you can add a little at a time to one of your jugs of soap). You will want about 2 teaspoons of alcohol to half a teaspoon of mica. You can use more alcohol than this, but it will start to overpower the scent of the soap very quickly.

Add a little of the dissolved colour to one of your jugs of soap and stir it in. Add more gradually until you get the colour you want. For a melt and pour swirl, I find it works best if the two colours of soap you use for the swirl are high-contrast, so, quite far apart e.g. black and white, bright pink and white, etc.

Pastels and white don’t tend to show up very well in a melt and pour swirl, but you could do one jug with some pastel and the other jug with a very intense colour, or a contrasting colour. I did quite a nice pink/dark pink strawberry melt and pour soap with pastel pink and vivid Barbie pink.

Once your colours are mixed up, let the soap cool to about 38 degrees celsius (about 100 fahrenheit). You can test this with an infrared thermometer if you have one, or you can tell if the soap has cooled enough because it starts to thicken very slightly. An infrared thermometer doesn’t need to touch the soap, making it ideal for soaping which can be hard to clean out of a regular thermometer. You may have to stir every few seconds to stop a skin forming on the top of the soap (don’t wait until the skin has formed, if that gets into your swirl it won’t look great). You will probably also need to pour your soap quickly, unless you live somewhere hot with the air conditioning turned off, like Malaysia, or a campervan in the Scottish summertime.

Once the soap is at the right temperature, pick up both jugs at the same time. Pour them into the mould from opposite corners. Where they meet, you should get a nice effect, you can emphasize this by moving both jugs in a clockwise direction (or anti-clockwise. As long as they both go the same way). You may have to practice this a bit to not just mix the two colours when you pour into the mould.

You might be wondering if you can make swirls with clay in melt and pour. You can, but the colours from clays don’t come out very strong so the contrast won’t be there. Indigo powder or charcoal powder could work very well, however, if you contrasted the dark colour with a lighter one like yellow French clay. The benefit of adding charcoal or clay to the soap is that your scent will work better, too, so it’s worth experimenting with using these natural colourants in your soaps!

What is a layer?

In cold process soap, this is where you pour one layer of soap (that’s been blended to medium trace) in one color, then pour another in another colour, often using zig-zag-type movements to get the colour to move around. To get a swirl in cold process, you pour your soap in lots of layers before putting your soap mould on a lazy Susan and spinning it. However, this requires you to work with thicker soap than you can easily get in melt and pour (because melt and pour is chemically different to the trace stage of cold process, it behaves differently and the viscosity is nowhere near the same). In cold process, the layers stay together because after you’ve poured them, the soap gets hot (saponification is an exothermic reaction which means it gives out heat) while it sets. In melt and pour soap, once you’ve poured it, all that happens is it cools down. So because the chemical reaction has already taken place before you ever get your block of melt and pour soap, the soap itself isn’t able to “cook” itself into a solid bar of soap. So in melt and pour, if you try and layer the same way you would in cold process, it won’t work. Your soap will just fall apart.

How do you layer in melt and pour?

This is a surprisingly controversial topic because people who don’t make melt and pour tend to believe you can’t layer it. But you can! And it’s surprisingly simple.

There are actually two ways to layer melt and pour soap. The traditional method and the one I’ve discovered. One is a lot better than the other. 😉 #sassysoapmaking

The first, less good method is to pour a layer, let it set, spray alcohol on it right before pouring the next layer. This makes your soap smell of alcohol because melt and pour doesn’t evaporate any alcohol in the mixture because it doesn’t go through gel phase. Yucky drunk soap.

The Double Melt Method

This second method, which I call the Double Melt method (patent pending… jk haha), produces a nicer result but you need to watch the soap closely to get it right. You will need a microwave for this.

Layer your soap by pouring, letting it form a decent skin (it should flex like a trampoline when you gently press down on it) and pouring the next layer, over and over until you have a full mould of soap.

Next, turn your microwave down to its defrost setting. Put the soap mould inside and turn it on for about 20 seconds for individual bars of soap or about 40-60 seconds for a big loaf mould (assuming your microwave is a standard 750 watt one). This should provide just enough heat to get the layers to melt together. You might get a little colour bleed between layers with this method.

Let the soap cool down and harden for about 1 hour before unmoulding it, that way if you’ve heated it too much, it will set fully.

I’ve gone into more detail on layering with the Double Melt Method in this separate article, including what to do if it all goes wrong (and my soapy disaster when I messed this up).