Longevity

prissymissy

New member
Joined
Sep 23, 2019
Messages
3
What do I add to my batches in order to prolong the life of the soaps? No matter how I "plug-in" the ingredients, the longevity measurement hardly increases. I guess that I incorrectly assumed, that hardness of a bar lead to longevity. Thanks ahead of time
 

Yooper

Administrator
Joined
Sep 7, 2019
Messages
45
Location
Upper Peninsula of Michigan/ Florida Gulf Coast
It may not be what you add- it's the combination of ingredients. What I mean is, no matter what you add to an 80% olive oil soap, it just won't last that long in the shower compared to many other formulations.

The short answer is to add more 'hard' oils. That is, oils that are solid at room temperature. Think tallow, lard, palm oil, coconut oil, shea butter, etc. Now, too much coconut oil can be drying to the skin, so the recipe matters.

Make sure the soap is fully cured- and even the bars with lower longevity in the calculator will last longer.

"Hardness" means how hard the bar is after curing. For example.,100% olive oil bars will eventually get hard enough to pound nails. But, it won't last that long in the shower because it does sort of melt a bit and get slimy.

I have a recipe in the 'sample recipes', and it's a bar with tallow, and it lasts seemingly forever!
 

prissymissy

New member
Joined
Sep 23, 2019
Messages
3
It may not be what you add- it's the combination of ingredients. What I mean is, no matter what you add to an 80% olive oil soap, it just won't last that long in the shower compared to many other formulations.

The short answer is to add more 'hard' oils. That is, oils that are solid at room temperature. Think tallow, lard, palm oil, coconut oil, shea butter, etc. Now, too much coconut oil can be drying to the skin, so the recipe matters.

Make sure the soap is fully cured- and even the bars with lower longevity in the calculator will last longer.

"Hardness" means how hard the bar is after curing. For example.,100% olive oil bars will eventually get hard enough to pound nails. But, it won't last that long in the shower because it does sort of melt a bit and get slimy.

I have a recipe in the 'sample recipes', and it's a bar with tallow, and it lasts seemingly forever!
Thank you so much for your in-depth explanation! I tall makes sense to me...I will try to incorporate more hard oils and increase curing time.
 

Bubbles

New member
Joined
Sep 24, 2019
Messages
2
What do I add to my batches in order to prolong the life of the soaps? No matter how I "plug-in" the ingredients, the longevity measurement hardly increases. I guess that I incorrectly assumed, that hardness of a bar lead to longevity. Thanks ahead of time
All handmade soap has a limited longevity compared to commercial soaps. I don't worry about it. I just advise my customers to not allow their soap to sit in a puddle of water.
 

bubblie

New member
Joined
Sep 24, 2019
Messages
3
What do I add to my batches in order to prolong the life of the soaps? No matter how I "plug-in" the ingredients, the longevity measurement hardly increases. I guess that I incorrectly assumed, that hardness of a bar lead to longevity. Thanks ahead of time
Sodium lactate might help as well. You add it to lye water before pouring it into your oils.
 

ChemicalPyros

New member
Joined
Nov 4, 2019
Messages
8
Location
Lebanon
The longevity (and hardness) of the soap is correlated with the quantity of the least soluble fatty acids.
Those fatty acids are mainly Palmitic acid and Stearic acid. I usually go for a ratio of 2:1 palmitic:stearic acid in the fatty acid profile of the soap. the more you increase those fatty acids in your soap the harder and more insoluble it will become.
this ratio stabilizes the foam and gives a nice usage time span.
you should note that too much of them in the recipe will destroy the foam. I would recommend that you go with around 20% palmitic acid and 10% stearic acid in the fatty acid profile for a maximum usage time span while still processable at room temperature.
 

hanimsmaik

New member
Joined
Oct 17, 2019
Messages
3
Hi everyone, and thanks for sharing. In "Cold Process" the softness and the short life-span is most likely due to unsaponified fat and free glycerin mixed with soap. Please feel free to read about other methods for soap making that result in reacting all fat, and exclude impurities and other unsaponifiables. I've created this free guide to share it, and it's the result for 28 years of making soap. Here: https://freesoapmakinglessons.wordpress.com

Also please feel free to write me an email if you wish to inquire about anything regarding the processes.

thanks
 

zlisik

New member
Joined
Nov 8, 2019
Messages
7
Isn't the longevity value a straight calculation of hardness-cleansing with this calculator? That's how I've read it described elsewhere as well.

Salt and sodium lactate don't effect the calculations in this calculator it seems. Nor do waxes. But all are commonly accepted as adding hardness. Perhaps they're too difficult to calculate?.

My feeling is that the calculated values are not absolute and more an estimate -- especially when you're adding ingredients that are not well documented or perhaps impossible to calculate accurately.

A castile soap is all over the graph but it's a well loved soap.. haha so maybe don't worry about it too much?
 

ChemicalPyros

New member
Joined
Nov 4, 2019
Messages
8
Location
Lebanon
The hardness, longevity and other characteristics in all online calculators (to the best of my knowledge) are overly simplified calculations. In my experience they are mostly adapted to multi-oil soaps. They become obsolete with single-oil soaps and specialty soaps. The reason behind this is that they use only one parameter for the estimates (the fatty acid content). Other parameters such as additives, curing time and temperature, whether cp, cpop, hp, superfatting, perfumes, ... are not taken into account with the calculators and since their effects are not fully understood to be implemented so it will come down to the soapmaker's experience. The more you make the more experienced you get and the better you understand the effects of all parameters.

In the mean time, this patent will explain why salts and organic salts improve the hardness and longevity of soaps.

https://patents.google.com/patent/US6218348B1/en

I know that my answer is ambiguous, but you have to take into account that when several parameters meet it is hard to understand the extent of the effect of each one on each property, only experimentation and serious notetaking will help you there.
 

Latest posts

Top