Food coloring in CP soap

[Lin]

I thought some of you might be interested in how food coloring works in CP soap. When researching, most say to not use it due to morphing. Well here are my results of basic food coloring in a CP bastile recipe in the batter and then after the full cure period. Its a basic 4 color food coloring set from walmart. FD&C Yellow 5, FD&C Red 40, F&C Blue 1, FD&C Red 3

Immediately after placing the food coloring in the soap batter, you can see the blue and the green begin to morph. In a short period of time, the color seems to morph and change multiple times. From left to right, green, yellow, blue, red.



By 24 hours after, the green appears very brownish grey while the blue is appearing a pretty lavender. The yellow remains a vivid yellow, and the red remains true as well.

Using red food coloring brings a similar issue with other types of red coloring, where if you don't use enough it can appear pink. So again you need to find the right amount for the color you're seeking while avoiding stained lather. In this experiment, the same number of drops was used for each of the colorants so the red resulted inbetween pale red and dark pink. At these concentrations of color, none resulted in a stained lather. After a full cure period the green appears greenish greyish brown, the yellow is still vibrant, the blue appears a beautiful vibrant purple, and the red is bright as well.



Despite morphing, all 4 colors could be useful in CP soap if they are consistent among different soap recipes. I would expect them to be, since its the alkaline pH which is said to cause the morphing. I used red 40 in making my starlight mint soap and had consistent results with this experiment, achieving a darker red with a higher concentration.

The green could be useful for an earthy result, while the other 3 come out specific hues.

 

[boyago]

Are you going to throw them on the sill to see how the sun will affect them?

 

[Lin]

Hmmm, not sure since they're being used! Does the sun bleach CP colorants? Its quite bright with natural light in the room the cured in and no fading, in fact they appear brighter and deeper now than after unmolding.

 

[songwind]

How many drops/lb did you use?

 

[boyago]

Yeah the sun will bleach out color over time. Especially blues and reds.

 

[Obsidian]

Except for the green, those colors are very nice. I would really appreciate it if you can track down the color box and see what kind of blue you have. Seems purple is such a hard color to achieve and you not only did it by accident but its a great shade.

 

[judymoody]

Thanks for sharing your results!

 

[Lin]

I will definitely track down the box! I know I didn't throw it away, but somehow it got separated from the bottles during cleanup. I had set it aside so it wouldn't get tossed so I'd be able to list the exact numbers for the colors! And yea the purple is what really interested me the most, and surprised my bf too. Its such a great shade and I was saying how a true purple is so hard to get. So I will definitely be using the blue food coloring to achieve purple again, on purpose, and will update the thread with results. I'm also thinking about testing how much red can be used before staining is an issue. Hopefully the photo with what the batter looks like immediately after colored will help people attempting to get the same saturation of purple.

As for exactly how much liquid was used, I'm not sure due to it being such a small amount of soap. It was 4 drops of color for each little soap, I can take a photo of the soap with a ruler to help give a better idea of size. They're nicely sized for hand soaps. Because of the interest, I guess I'll stop using them as hand soaps so I can continue to experiment and see how they continue to age. I'm not sure about sticking them in a window though because I don't think thats a very accurate representation of real life. As I said before the room they're in is very brightly lit with natural light during the day, so thats probably more realistic to use than stuck in a windowsill.

 

[user 12568]

I don't use colourants in my soaps, but still find this thread very interesting. I'd be interested in seeing how well they age.

 

[TVivian]

I did a very similar test with food colors awhile ago. The sun does affect the color especially the red. I got a really pretty pink like that on a soap and the sun coming in from a window turned it a weird light grey. This really only matters if you're trying to sell. For personal use.. Why not?

 

[grayceworks]

Except for the green, those colors are very nice. I would really appreciate it if you can track down the color box and see what kind of blue you have. Seems purple is such a hard color to achieve and you not only did it by accident but its a great shade.

The McCormicck brand food coloring produces this result. Their blue is a combo of red 40 and blue3. Both food, drug, and cosmetic safe. I get this same color. I used about half a bottle in 2lbs the first time cuz it seemed like it kept disappearing lol. It turned pale purple right after gel, then gradually darkened to that lovely purple.