HO sunflower CP castile, testing the next natural green dye, and new mould!

[ResolvableOwl]

This nifty Lego brick silicone mould is new in my collection. To inaugurate it, I made a straight HO sunflower castile soap. Pure high-oleic sunflower oil, NaOH lye with 39% concentration, with 1.4%ppo lactic acid (equivalent to 2.9%ppo 60% sodium lactate). With a saponification value of 0.135, this means a fairly low lye discount of 1.25%. I am aware of multiple tricks to avoid typical castile notorieties, but I decided to keep things simple.

To little surprise, it was a pain to thicken up. More than a day after casting, the batter still had a “thick trace” texture … unmolding was just barely possible after three days, lactate addition to little avail … and “a bit” more patience to be expected until fully cured …


For a small part of the batter, I intended a slightly less minimalistic fate: A month ago, I had mixed some coconut oil with erva-mate chimarrão (that bright green yerba mate powder from southern Brazil), kept it liquid at a warm place, and filtered the leaf powder off the coconut oil a few days ago. This dark green macerate went into part of the HO sunflower batter, adding 12% coconut oil, and lifting the superfat accordingly.

The pure soap is the lightest in colour I've ever made so far, and I wouldn't be surprised if it becomes even brighter with curing. That makes it the ideal matrix to judge what happens to the yerba mate colour. Everyone who knows yerba mate knows how terribly hard to clean the dark green stains are that it leaves everywhere, particularly around the kitchen sink. However, these are water-soluble, and here I have a fatty macerate, i. e. I expect it to be more similar to most other green plant dyes.

Adding yerba mate powder to soap as a whole (without the oil extraction step) is possible (it adds a mild peeling effect), but I haven't found a dosage yet where it turns completely black (but the lather becomes bright green!). But this is a story for another time.

In any case, I'll keep you updated, particularly about the development of the white and green colours.

 

[cmzaha]

I am sorry you did not read my review of 100% Sunflower HO soap, it is not particularly nice, but maybe you will like it. I found it did not lather at all.

 

[ResolvableOwl]

Thanks for the pointer! I'll check yours out.

We'll see. Most probably, these soaps won't stay in this condition forever, but be rebatched in one way or another. And regarding to lather: when cleaning the moulds, I noticed quite some foam, but this could have been the coconut oil too.

 

[ResolvableOwl]

Update 86 days after casting (I've tried to reproduce lighting as faithful as possible with respect to the first photo):



The white bars have developed a fine, velvety soda ash cover a few days after unmoulding, and have become rock hard and a bit translucent by one month in (you can see both at the right corner). Now they feel and sound “light”, as if they were a bit “hollow” (like wood).
No soda ash on the green soap (high-superfat with coconut), and it eventually became somewhat hard after some two months, but feels “heavy”/massive (like candles).
Colour wise, the green has faded a bit (dark storage at room temperature), and lost a bit of its freshness (a bit more yellowish hue).

I am a bit undecided when I should test them in their natural habitat (bathroom). They appear to be through the majority of cure, yet you can't wait long enough for castile soap… and it would mean that I have to finish up my weight loss bookkeeping … Opinions?

 

[earlene]

You have more than one of each, yes? Or only 2 of white & one of green? Keep up the weight loss on one of the white. An d test the other white at sink-side. That is unless you really want to do a side-by-side comparison of the two in terms of how the yerba matte feels in use vs sans y.m.

 

[ResolvableOwl]

I had three of the white ones and two green, but I've used up all but one each for other projects. I'll probably weigh the last one, then cut/saw/break it in half, and weigh the parts, before giving it a try. Honestly, the large 4×2 brick is a bit too large for my taste anyway.

ETA: The green soap isn't so much of a soap quality long-term test, but more a colour experiment. Addition of the infused coconut oil was a spontaneous idea; that's also why the superfat is totally off the chart. I don't expect it to be a decent soap at all.

 

[KimW]

FWIW: Not sure of the temperature limit of your mold, but I find that if I CPOP my full liquid oil soaps the next day/12 hrs later, they harden up nicely. 12 hours seems to be a weird magical sweet spot. If I CPOP right away it doesn't seem to help terribly much, nor does 8 hours later. Of course, I haven't tested times between 8hrs and 12, so 12 might not be so magical.

 

[ResolvableOwl]

It's silicone, so fully CPOP safe. Next time when I make boring castile soap, I'll definitely CPOP then (and hopefully remember your words of patience to not take them out of the oven too early).

 

[szaza]

That's a pretty green! I'm very curious to see how it holds up. Definitely keep storing it in a dark place

 

[ResolvableOwl]

Hi @szaza Yes, your incredibly elaborated thread about natural colours was one of the reasons for me to try this out! Who knows, maybe it might even be preparatory for something I'm not (yet) allowed to talk about.

 

[ResolvableOwl]

Day 92 – Test time!


(This photo is deliberately underexposed, so that you can see the pearly shimmer of the dried surface.)

I'm really happy with this bar of soap! I had feared the worst when I extrapolated castile slime from 60% HO soaps, but it actually wasn't that bad. The edged shape was a bit uncomfortable (scratchy) at first, and I had to rub quite a bit until something dissolved and eventually gave some lather (and just a few gooey ropes too). The skin feels very clean, warm and dry afterwards. If I had to criticise this recipe in a blind test, I'd recommend lowering coconut oil by 5% or 10% .
But the hardness is above any suspicion. Time will show if the purportedly mediocre longevity of high-oleic soaps hits. My impression so far is no worse than these mango-rice bran bars that dissolved tooooo quickly.

Before testing, I broke the bar into halves, and one half will be weighted each month or so for indefinite time. The bar was surprisingly difficult to break, but it eventually broke cleanly, with a sound like a good bar of chocolate, and the fracture surface also looks like that: conchoidal with a uniform roughness.


Drying curve: The fresh soap batter contained 15.3% water, so the absolute minimum dry mass is 84.7% of the initial weight. A large portion of the moisture (just below half of total water) evaporated within the first month. Ever since then, it is losing weight at a rate of 1% per month, with no signs of slowing down so far (at that speed, the theoretical limit is hit after about one year). Note how the three bars I initially watched, were stunningly similar in their drying speed.
Dimension wise, the width of the bars shrunk from initially 45 mm down to about 43 mm. Assuming isometric shrinkage, that's about a volume loss of very roughly 13%, which doesn't quite fit to my impression of being light and “hollow”.

Anyway, expect updates on this in loose intervals.

 

[ResolvableOwl]

I also must refer to @DeeAnna's similar experiment a few years ago:
https://www.soapmakingforum.com/threads/cure-time.35831/That whole thread is highly worth reading, full of insights of what is happening inside a soap during cure.
She presents a graph similar to mine above, with a better time resolution and over a shorter period of time, for good reasons: her soaps, made from realistic, balanced oil blends, went through curing in an average time. Saturation (flattening curve) is visible from about a month in.

Meanwhile, my castile soap is much more “lazy” and moves very slowly… (Note how it has needed three months to lose as much moisture as hers by the four week mark.)

 

[ResolvableOwl]

Time flies, 7 months in, time for another update!

Weight loss has slowed down, but hasn't fully stopped yet:

Averaged over the last months, evaporation losses are about a third of the drying rate with respect to the months 2–4.

Not too many suprises with the soap itself. It's about the hardest bar of soap of all I have. Its castile slime emission is beyond words. Lather is loose, translucent, runny and not very stable, but it is there and I can well live with it. The soap feels somewhat ropy and sticky on the skin, but is easily washed away, to leave the skin with a sensation of deep cleanliness, maybe even a bit too deep. Moist but water-moist, that after the water has dried up, makes the skin feel a bit chalky. Not the least conditioning, emollient, or nourishing. My skin does not like this soap; at least in its current state, it might get used to it, but I won't chance it (and if it's just to conserve my test bar for more tests in the further future).

 

[ResolvableOwl]

Some more weight loss curves found across SMF & the internet:

The lye concentration experiment by @ngian
Waiting For A Cure: Is It Worth The Weight? - Wholesale Supplies Plus (Guest article by Kevin Dunn)