The past two months, I’ve been busy testing micas, pigments and lakes in cold process soaps and bath bombs. I’ve blogged about it, but to make it easier for you to find these posts, I’ve created some colour guides for you to use and download.
FD&C is an American labelling standard, which stands for Food, Drugs and Cosmetic. FD&C dyes have gone through rigorous testing, which makes them safe for use in foods and cosmetics, however, they are artificially made (not natural) and I will leave it up to you to decide if they are healthy or not. The main difference between the FD&C dyes and lakes, is that the FD&C dyes are soluble in water and that the lakes are produced from the FD&C dyes and an aluminium salt, which makes the lake oil-dispersible (but not oil-soluble), meaning it can be mixed with oil.
For the following tests, I used lakes from Pure Nature, which are available for $5 for 10 g. These are strong colourants and they will last you for quite a while. Although, I don’t recommend them for cold process soap, you can still use them in other products, such as lotions, bath bombs and melt and pour soaps.
They are all non-toxic, and approved for food and cosmetic use.
Cold process soap
As mentioned earlier, lakes are best dispersed in oil, and will not dissolve in water. However, I tested the lakes mixed with both water and oil, and the results were the same. Just make sure you give the bottle with water a good shake before each use. The usage rate for lakes in cold process soap is 1/8 – 1/4 teaspoon of colour, mixed with 1 tablespoon oil, per 500 g of soap. I used 1/4 teaspoon per 500 g soap in the tests.
You can see in the picture above, that the lakes don’t always perform in cold process soap. The blue lake turned into purple shade after gelling, before gelling it was a greyish shade and the red was orange. The reason for this is that the FD&C dyes don’t like the high pH environment during the soap making process. This is the same reason why food colouring doesn’t work in cold process soap making and some micas can give you funny results. The only lakes that seem to stay true to their colours are yellow and orange, and red only after gelling, which doesn’t leave you with a lot of options for colour mixing.
Melt and pour soap
Melt and pour bases are finished soap bases to which you only add colour and fragrance. That means that you can’t add extra water or oil to the bases. You also can’t add the powder directly to the soap, because it will leave speckles in your soap.
Pre-mixing the lakes in glycerin, on the other hand, will give you bright, even colours throughout your soap. The colours will stay true, because there is no saponification like in cold process soap, and they are very easy to blend.
The only problem you might come across is when you didn’t mix the colour properly into the glycerin. In this case, you will get speckles at the bottom of the soap. Always mix well and shake bottle before use!
Lakes are often used to colour bath bombs, because, as powders, they are easy to mix into the dry ingredients and result in brightly coloured bath bombs. To use the lakes, add a pinch of colour to your finished bath bomb mixture. Only add only a tiny amount at a time because they are quite strong in colour. Keep adding until you reach the colour you desire. To achieve the colours in the pictures below, I added 0.3g (two 0.15CC scoops) to 1 cup of bath bomb mixture. As I said, you only need a very tiny amount!
However, using the lakes in powder form will leave the bath bombs speckled, because the colours don’t blend with the other ingredients (remember: not water-soluble). An alternative option is to pre-mix the lakes with glycerin. Glycerin won’t make your bath bombs fizz and it will blend the bath bombs more evenly. Another advantage of pre-mixing the lake with the glycerin is that you can store it for up to a year without having to add a preservative to it.
The colours are a lot more evenly dispersed through the bath bomb, and they mix better than in powder form, as shown in the picture below.
So to summarise, lakes are great for melt and pour bases and bath bombs, as long as you pre-mix them with glycerin. For cold process soap, you have to be aware that they can morph colours and that there are better alternatives out there for cold process soap.
I’m a big fan of soap pigments. They tend to colour my soap very evenly and are easy to use. They are definitely a lot less messy than lakes and micas, and also a little goes a long way. I would strongly suggest to invest in a trio of soap pigments, if you are into cold process soap making!
I use soap pigments from Pure Nature, which are available for $12 per 10 g. They are a bit more expensive than the lakes and micas, but are a lot more economical and will last you for a long time. They stock the basic three colours: yellow, red and blue, which can be easily mixed to create more colours, such as green and blue.
Soap pigments are water-soluble and very easy to work with. The pigments are mixed with water before use, and then added to the soap at trace. If you pre-mix them, you can store them in the fridge for a week. I use these little mini-bottles from Systema for my prepared colours.
The recommended usage rate for these pigments is 0.02%, which is really a very tiny amount. But I found that you can easily double the usage rate to 0.04% without any trouble – meaning no staining and no coloured foam. To calculate the usage rate into workable amounts, I added 2 mini-scoops (0.15CC each) to 3 teaspoons of water, which gives me exactly 0.02% (MATHS: 0.3 ml / 15 ml = 0.02). Add 1 teaspoon of the solution to 500g soap for a 0.02% usage rate, and 2 teaspoons of the solution to 500g soap for a 0.04% usage rate.
As mentioned earlier, the pigments can be easily mixed to create more colours. For a green, mix one part blue with one part yellow. Add more yellow for a more yellowish grassy green, or more blue for a teal colour. One part red and one part yellow will make orange.
Purples and lavender are a bit more difficult to get right. Purples tend to be more toward the red end of the colour spectrum, so mixing 1/2 red and 1/2 blue usually doesn’t work. With the pigments, I found the ratio 2/3 red to 1/3 blue worked well for me. If you wanted a more reddish purple, you could even increase to 3/4 red to 1/4 blue and increase the usage rate to 0.04%.
Adding titanium dioxide will whiten your soap to make your colour appear more true, as you can see in the picture below. To get the shade of lavender, I added 1 teaspoon of titanium dioxide to 500 g of soap.