Superfat and dissolving rate

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cascarral

Well-Known Member
Hello!

I made some different recipes to try out and compare. One of them is OO 60% CO 25% Cocoa 15% and did two versions, first one with 5% SF and the other one 2%, hoping the later one would last longer with the reduced SF but to my surprise it has been the opposite!

For the test I used little 15.62 gr soaps and have been using them and weighing them to compare how fast they dissolve. After 10 uses the 5% SF is 9.65 gr and the other 9.05 gr, I know .60 grams is not much but I'm curios of why this is happening, any theories?

The only thing I can think of is that I made 5%SF 8 weeks ago and the 2% 6 weeks ago, so maybe this 2 week difference cure had something to do? Or maybe the extra fat makes it harder for the soap to dissolve?

DeeAnna

Well-Known Member
I don't have any theories because I haven't a clue if the difference is a valid difference. You've not tested the two soaps enough times to detect statistically significant differences.

A scientist repeats her experiments many times and analyzes the data from all the experiments. Only then can she tell if there's a real difference. You've only done one test. It's a nice start, but this tiny amount of data is not enough to draw good conclusions from.

You're also not doing a "blind" test which minimizes the effects of "bias" in your test. In other words, you know which soap is which and knowing this will affect your results too.

It's like calculating the gas mileage of a car. It's important to record the miles driven and the total gas used over a reasonably long time to get an accurate answer. The gas mileage for one tank of gas can be a little different from the next tank. If you find the average gas mileage for a season or a yea or some longer time like this, you will get a much more accurate idea of what the gas mileage is.

cascarral

Well-Known Member
I don't have any theories because I haven't a clue if the difference is a valid difference. You've not tested the two soaps enough times to detect statistically significant differences.

A scientist repeats her experiments many times and analyzes the data from all the experiments. Only then can she tell if there's a real difference. You've only done one test. It's a nice start, but this tiny amount of data is not enough to draw good conclusions from.

You're also not doing a "blind" test which minimizes the effects of "bias" in your test. In other words, you know which soap is which and knowing this will affect your results too.

It's like calculating the gas mileage of a car. It's important to record the miles driven and the total gas used over a reasonably long time to get an accurate answer. The gas mileage for one tank of gas can be a little different from the next tank. If you find the average gas mileage for a season or a yea or some longer time like this, you will get a much more accurate idea of what the gas mileage is.

Thank you for your answer! I'll keep testing and see how it progresses.

I did tested blindly, though, just now I checked which was which and was surprised by the results.

I don't have any theories because I haven't a clue if the difference is a valid difference. You've not tested the two soaps enough times to detect statistically significant differences.

A scientist repeats her experiments many times and analyzes the data from all the experiments. Only then can she tell if there's a real difference. You've only done one test. It's a nice start, but this tiny amount of data is not enough to draw good conclusions from.

You're also not doing a "blind" test which minimizes the effects of "bias" in your test. In other words, you know which soap is which and knowing this will affect your results too.

It's like calculating the gas mileage of a car. It's important to record the miles driven and the total gas used over a reasonably long time to get an accurate answer. The gas mileage for one tank of gas can be a little different from the next tank. If you find the average gas mileage for a season or a yea or some longer time like this, you will get a much more accurate idea of what the gas mileage is.
But theoretically a soap with more SF will dissolve faster than another one with the same recipe but less SF, right? Or is my logic wrong?

DeeAnna

Well-Known Member
That's seems to be a reasonable hypothesis to test, but I don't have an answer for you. If you collect enough data to draw sound conclusions, you'll be the expert on this issue, not me.

cascarral

Well-Known Member
That's seems to be a reasonable hypothesis to test, but I don't have an answer for you. If you collect enough data to draw sound conclusions, you'll be the expert on this issue, not me.
Thanks for your help I will keep testing and let you know what I observe.

Becky1024

Well-Known Member
It might be that a saponified oil is the sodium salt of the fatty acid, and the salt has a hydrophilic end which dissolves in water. So the soap with lower superfat has more sodium salts in it and less of the oil.

Or it could be the cure time.

Keep us posted! This is interesting!

GemstonePony

Supporting Member
The amount of water a soap contains does impact solubility. One of your soaps is 3/4 the age of the other. I would compare again in a few months, when 2 weeks of difference is a less significant age difference.

cascarral

Well-Known Member
Hi again

I have continued my experiments, using the 4 soaps I made. This are the same batches because new ones would take a month so I'll keep you posted on that.

However this is what ?`ve observed so far:

I made 4 formulas to see which one was lasted the longest since all 4 of them have very high soluble oils: A. Olive 40%, canola 20%, coconut 20%, cocoa 10%, shea 10% B. Olive 40%, canola 15%, coconut 25%, cocoa 10%, shea 10% C. Olive 60%, coconut 25%, cocoa 15% (2% SF) and D. was the same as C but with 5% SF, same as A and B.

I made the soaps in different days so I'll write this down in case someone is interested: A: august 25, B: august 20, C: september 3, D: august 21.

For testing I washed my hands for 1 min with each soap, let dry on a flat plate and repeated. The drying periods were from 2 hours do a day. I did 10 tests.

Results by lost weight:

A: Total: 3.87 Average per use: .774
B: Total: 4.61 Average per use: .922
C: Total: 4.1 Average per use: .82
D: Total: 3.87 Average per use: .774

So the one that lost the most is soap B, which is funny because B is recipe A tweaked to make it slightly more longlasting haha! I guess canola dissolves faster than CO which now seems obvious.

Again, against my expectations, the 2% SF soap (Soap C) dissolved faster than it's more superfatted version (D). Here cure time could be a factor.

earlene

Grandmother & Soaper
Lifetime Supporter
Hi again

I have continued my experiments, using the 4 soaps I made. This are the same batches because new ones would take a month so I'll keep you posted on that.

However this is what ?`ve observed so far:

I made 4 formulas to see which one was lasted the longest since all 4 of them have very high soluble oils: A. Olive 40%, canola 20%, coconut 20%, cocoa 10%, shea 10% B. Olive 40%, canola 15%, coconut 25%, cocoa 10%, shea 10% C. Olive 60%, coconut 25%, cocoa 15% (2% SF) and D. was the same as C but with 5% SF, same as A and B.

I made the soaps in different days so I'll write this down in case someone is interested: A: august 25, B: august 20, C: september 3, D: august 21.

For testing I washed my hands for 1 min with each soap, let dry on a flat plate and repeated. The drying periods were from 2 hours do a day. I did 10 tests.

Results by lost weight:

A: Total: 3.87 Average per use: .774
B: Total: 4.61 Average per use: .922
C: Total: 4.1 Average per use: .82
D: Total: 3.87 Average per use: .774

So the one that lost the most is soap B, which is funny because B is recipe A tweaked to make it slightly more longlasting haha! I guess canola dissolves faster than CO which now seems obvious.

Again, against my expectations, the 2% SF soap (Soap C) dissolved faster than it's more superfatted version (D). Here cure time could be a factor.

What is your weight of measure? Grams, I assume, but you don't actually say. Or is it ounces?

ETA: In reading a post higher in the thread you do mention grams, but it would be useful to carry that through in each post.

DeeAnna

Well-Known Member
"...So the one that lost the most is soap B, which is funny because B is recipe A tweaked to make it slightly more longlasting ..."

I gather you altered A by reduced the canola by 5% and increased the coconut by 5% to get B. I'm not sure why you thought this change would increase the longevity of the soap. Both fats are high in fatty acids that make highly water-soluble soaps.

I would reduce BOTH of these fats and increase fats that have a decent amount of stearic and palmitic acids. Stearic and palmitic acids make a less soluble soap, so increasing these FAs in your recipe is much more likely to increase longevity.

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cascarral

Well-Known Member
What is your weight of measure? Grams, I assume, but you don't actually say. Or is it ounces?

ETA: In reading a post higher in the thread you do mention grams, but it would be useful to carry that through in each post.
It is grams! Sorry for not clearing that

cascarral

Well-Known Member
"...So the one that lost the most is soap B, which is funny because B is recipe A tweaked to make it slightly more longlasting ..."

I gather you altered A by reduced the canola by 5% and increased the coconut by 5% to get B. I'm not sure why you thought this change would increase the longevity of the soap. Both fats are high in fatty acids that make highly water-soluble soaps.

I would reduce BOTH of these fats and increase fats that have a decent amount of stearic and palmitic acids. Stearic and palmitic acids make a less soluble soap, so increasing these FAs in your recipe is much more likely to increase longevity.
Yes, I was justr trying out some small changes to see what would happen. Will have that in mind, thank you