Math Help (Determining Hardness, etc)

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Kitty_Boots

Active Member
All right, perhaps someone here is a mathematician (or at least more mathy than me!)..

I'm trying to figure out the actual value of an oil based on the % in my soap..

For example.. Coconut Oil has the following characteristics:

Hardness: 79
Cleansing: 67
Conditioning: 10
Bubbly Lather: 67
Creamy Lather: 12

Now, say I have 30% coconut oil in my recipe.. What is the actual hardness of the soap.. Because that 79 is going to have to spread across the whole 100% percent of the soap... Not just 30%

So I would formulate the question:

If the hardness is 79 @ 30%, what is the hardness @ 100%?

This might be really easy but my brain isn't doing it. haha.

Thanks for the help in advance.

dibbles

Supporting Member
Supporting Member
The hardness value for each of the oils in a recipe will remain the same. The hardness for the entire recipe will change. It looks like you are using Soap Calc? You need to enter your total oil weight, and then the % all of the oils in your recipe. As you enter each of the oils the fatty acid profile will show in the Soap Qualities column for each individual oil. Click on Calculate Recipe, and the fatty acid numbers will reflect the entire recipe in the right (all) column. To see the fatty acid profile numbers from an individual oil, just highlight it in the list of Oils, Fats, Waxes and that will display the profile for the selected oil in the left (one) column.

As an example, if you are making a recipe with 32 ounces of oils, 20% coconut, 40% lard, 35% olive oil and 5% castor oil, the hardness value of your entire recipe will be 39. The coconut oil hardness value will still be 79. If you reduce the coconut to 15% and add it to the olive oil, the hardness for the entire recipe will drop to 35%, but the coconut will still be 79.

I haven't had enough coffee this morning, so I hope this makes sense.

lsg

Staff member
Moderator
Supporting Member
Yes, enter all the oils and fats before figuring the hardness. However, SoapCalc is not infallible. It gives Castile soap a relatively low hardness number, but when cured for several months, Castile is a very hard soap.

ngian

Well-Known Member
Hardness is something that can be achieved with many variables so it isn't necessary to calculate with such analysis and maths.

If I wanted hardness I would:

- use as much as possible Palmitic and Stearic acids if I wanted hardness to live longer even after a few uses of the soap bar, as these acids, apart from hard, they are not much water soluble as other acids.

- use less water in the recipe as less moisture in the soap initially, the soap is getting harder sooner while curing

- use salt to also help the initial hardness of soap while unmolding / curring.

Physically hard can also be a bar with more oleic and Linoleic acids if you water discount and let it cure for at least 2 months but after the first uses it will be not as hard between uses as high in Palmitic /Stearic / Lauric / Myristic Acids recipes.

Those are my assumptions from my little experience and my perception.

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Kitty_Boots

Active Member
lol I wasn't using soap calc.. I was trying to figure it out on my own without knowledge that soap calc existed.. Hahaha! I've found it though and the math I was doing was comparable to soap calc (except soap calc is waaaay more efficient).

Thank you!

Pilar

Supporting Member
Hardness is something that can be achieved with many variables so it isn't necessary to calculate with such analysis and maths.

If I wanted hardness I would:

- use as much as possible Palmitic and Stearic acids if I wanted hardness to live longer even after a few uses of the soap bar, as these acids, apart from hard, they are not much water soluble as other acids.

- use less water in the recipe as less moisture in the soap initially, the soap is getting harder sooner while curing

- use salt to also help the initial hardness of soap while unmolding / curring.

Physically hard can also be a bar with more oleic and Linoleic acids if you water discount and let it cure for at least 2 months but after the first uses it will be not as hard between uses as high in Palmitic /Stearic / Lauric / Myristic Acids recipes.

Those are my assumptions from my little experience and my perception.

Japanese calculators calculates hardness with acids: lauric +myristic + palmitic + stearic + ricinoleic + oleic. What do you think?

Pilar

Supporting Member
Sorry, the characteristics of Asian calculators are:
Hardness and Bubbly as Soapcalc
Cleaning such as solubility capacity
Collapse dificulty as the ability to soften a soap to external factors such as moisture in the bathroom or that dissolves in a wet surface.
Stability as oxidation and longevity
Conditioning understood as the reaction of the soap on the skin

Sorry, my english is terrible..

Kitty_Boots

Active Member
Thanks Steve.. I've been working on my own little chart to help formulate better (I'm very visual haha).. This is it so far (more oils will be added as I acquire them, or if they intrigue me).

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