Green colourant?
- Thread starter KiwiMoose
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P.S. all this discussion of natural green colorants and my recollection of how we process seawater samples for chlorophyll concentration has driven me to start a little research project on the sensitivity of various plant pigments to temperature, light, pH and any other major variables I happen to come across. For example, in the lab we extract plant chlorophyll (and another pigment called phaeophytin) from marine algal samples using a solvent, measure the color intensity to get concentration, add an acid and measure again. The acid destroys the chlorophyll, leaving only the phaeophytin, which is then subtracted out to get the chlorophyll concentration. It was the part of the process that involves obliterating the chlorophyll that got me thinking. As sensitive as chlorophyll is to low pH, the color stability of many natural greens in soap batter suggests that chlorophyll is not very sensitive to high pH. You will be happy to know that food scientists have also shown this in many experiments.It also caught my attention that the critical temperatures for chlorophyll degradation in some of the experiments were in the range of 140F to 170F, the temp range CP soaps with 33% lye concentration are in while they’re going through saponification and/or gel. Differences in color stability of various natural plant pigments can be predicted based on chemical structure. I’m going to start making a table and if and when I finish it, I will report back.
I also learned that consumer demand is driving the food industry to research ways to make stable natural green colorants for edible products. Green is one of the most in demand colors and also one of the most challenging. They’re talking about microencapsulating chlorophyll. Maybe whatever they come up with will also work in soap!
How about this approach for selling soaps colored with parsley, matcha tea, comfrey or your other favorite green colorant? “This soap is made with natural colorant X. Store away from light until ready to use and then expect the beautiful color to last for up to X months if kept out of direct sunlight.” I would buy that!
I am looking forward to your ongoing studies on this, and would love to see any preliminary reports you are willing to share. I am particularly interested in the use of chlorophyl and how temperature plays a part in conjunction with the high pH of lye soap. And with the other items you mentioned, like matcha tea, parsley, etc.
You may find this interesting: I once made soap with spinach, which I dried before grinding to as fine as powder as I could manage (in my Bullet or spice grinder - I don't remember which atm) and although it made for a very nice colored swirl, it faded over time to a consistent light beige color on the surface of the soap. When I cut it open, the green was still there, so I expect light &/or Oxygen played a part in the color fading. But, this is the interesting part: You know how spinach deepens in color when you cook it? Well so did this soap when I added it to boiling water. I discovered this quite by accident because I was salting out some soap and when I added a partially cut bar to the pot, it started turning just like fresh spinach does. I found that fascinating.
All of these observations are important for teasing out which factors are likely to be the most important ones. How did you store your soap that eventually faded? I haven’t seem much about oxygen having an effect, but will keep it in mind. Was the salt in the pot plain table salt?
I have some parsley sitting in a bowl for 4 days now after hydrating it with a little water, adding some sodium bicarbonate to raise the pH a little, adding some alcohol to slow down growth of nasties and adding some glycerin to keep it from drying out. It started out as dried green parsley from COSTCO that I ground down somewhat, but not to a powder. It’s bright green. I put some of the same parsley into a jar with olive oil and left it sitting on the counter. It has turned an olive color.
Good questions, indeed!
Before I knew any better, I put my curing soap in a room with lots of bright light. It's a personal thing for me - I like lots of natural light and rarely ever cover my windows anywhere in my house. That room has lots of sunlight. Bare to the open air, of course, for air circulation. Here's a link to a photo of that soap: https://www.soapmakingforum.com/attachments/img_20160215_221116-jpg.29785/
Salting out was with regular table salt, although I'm think I used the non-iodized, but am not certain. I keep both on hand based on the different uses. But my notes from that day don't indicate which I used. Here is a link to the day I started my first salting out: https://www.soapmakingforum.com/thr...ave-you-done-today.42556/page-253#post-614297
Zany_in_CO
Saponifier
It's an old timey process that removes impurities as well as the glycerin. I tried it. I liked the result. I lost about a third of the soap in the process, tho. Doesn't work well for castile. But fun to do. Good ole DeeAnna has instructions on her soapy stuff page. Scroll down about 1/3 of the way... if you don't get distracted by something that comes before it, you should get in and out within a reasonable amount of time! <Gaffaw>
https://classicbells.com/soap/soapyStuff.asp
I think light is probably the biggest culprit in fading, but it would be interesting to see/know the influence of air flow on fading! there's this soap I made last summer with 2:1parts of spirulina and wheetgrass. I still have one bar that I kept in my basement (exposed to air but not light). My mom also still has a bar that was exposed to both air and light and hers faded considerably more. (I'm away for the weekend, try to post pics when I'm home)
Darn it, turns out I just hadn't seen my bar for longer than I thought. When I went to take a picture of mine it looked almost the same as my mom's... Back to the drawing board!
My mom's bar (exposed to light and air)
My bar (exposed to air, not light)
My mom's bar (exposed to light and air)
My bar (exposed to air, not light)
KiwiSoap
Well-Known Member
Not a bother, we experiment and learn! We may be stacking up the ways not to make green soap, however if we keep on trying maybe one day we'll find a way
Thanks for sharing!
Photo updates on my spirulina soap:
Photo taken 30th May ( only a few days into the cure):
And photo taken today, 21st June. slightly paler but the lighting was different. I can see it is paler though. Note: the spirulina is only on the bottom half of the soap - helped by some green mica (the same as is in the top half of the soap) and a tiny bit of charcoal.
It has been stored out of direct light - but in open shelves in a room with natural light coming in all day through the window.
Photo taken 30th May ( only a few days into the cure):
And photo taken today, 21st June. slightly paler but the lighting was different. I can see it is paler though. Note: the spirulina is only on the bottom half of the soap - helped by some green mica (the same as is in the top half of the soap) and a tiny bit of charcoal.
It has been stored out of direct light - but in open shelves in a room with natural light coming in all day through the window.
gloopygloop
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Have you tried green matcha tea? I know it is often used in food and confectionary and gives anything with it a varying shades of green depending on how much, I think only a tiny amount is required to get a green colour.
I have, and it turned brown every time[emoji22]
Very pretty soaps @KiwiMoose (as always). I really like your stamp[emoji3]
@KiwiMoose still looks great! It’s a wonderful deep green.
I used Matcha tea powder a few weeks ago. The powder was bright green from the bag and the color stayed bright in the soap and is still bright. I posted a pic of the soaps in the molds in this thread, which also has pics of a great set of green test soaps made by @KiwiSoap.
I used Matcha tea powder a few weeks ago. The powder was bright green from the bag and the color stayed bright in the soap and is still bright. I posted a pic of the soaps in the molds in this thread, which also has pics of a great set of green test soaps made by @KiwiSoap.
KiwiSoap
Well-Known Member
Wow, I am also surprised but very happy to hear your matcha soaps have kept their colour, that was a lovely shade! @KiwiMoose's soaps have also done well keeping up their appearances, it was good thinking to have those reinforcements in place. The true test will come with time, but for now it's looking good for fresh matcha!
Zany_in_CO
Saponifier
Nice stamp!
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