How hard is hard?

[Madelyn Cole]

Hello! Most store bought bar soaps are hard to the touch, meaning there is no give. I personally like this quality, but I'm unsure how to achieve this in CP soap. I've read a lot about the various soap properties - hardness, cleansing, bubbly etc. and have learned that solid oils greatly contribute to the "hardness" of the final product. But does this "hardness" property of CP soap translate to the same kind of "hardness" in store bought soap? What do CP soap makers find is the best percentage of solid oils to achieve a truly "hard" bar? If going for a true "hardness" quality, do you risk producing a final product that is drying? Also, I'm curious to hear from others if achieving a "hard" bar is the goal? Below are the recipes of the first two batches I made this weekend. They are both firming up nicely, but still have some give to them. Am I right to conclude that they will harden more as they cure?

Batch 1: Canola oil, coconut oil, lard, avocado oil - all 25%
Batch 2: Canola oil 25%, coconut oil 25%, palm oil 20%, avocado oil 20% cocoa butter 10%

 

[lenarenee]

Commercial soaps are compressed so they can reach a hardness handmade soapers can't.

A 100% olive oil soap that's well cured (several month), or a soap made with a lot of tallow, are the hardest (closest to commercial) that I've ever come to. However, olive oil soap is "thirsty" and absorbs a lot of water and can take a hard, well cured soap bar and soften it, even get gloppy. It don't use much olive oil because of that.

To show the paradox of the soap calculator term "hardness" - bar made with 100% coconut oil is very hard - but very soluble and melts away quickly.

Its stearic acid and palmitic acid that make a soap hard (but also lots of olive oil + long cure) and those are found in higher amounts in the hard oils that you mentioned - palm, lard, tallow, coconut, butters.

You may just have to commit to making small batches to test out recipes to see if you can find one that makes you happy.

It might be beneficial for you to make 1 lb batches of any hard oil you're interested in - and see what the outcome is and if you might like it in soap.

ETA: removed incorrect information (thanks Deanna!)

 

[Madelyn Cole]

Thanks lenarenee! That's helpful!

 

[Dean]

Hi Madelyn. I love that name.



My recipie has a soap calc rating of 54...the highest in the calcs recommended range. It is not drying and lathers great. However, it is not as hard as a commercial bar that can get razor thin and not bend.

I got a rock hard bar with @Zany_in_CO’s recipe which uses salt as a hardener.

Perhaps u can get that super hard bar by aiming for hardness factor of 54 and adding salt?

BTW...others may diagree but I find gel produces a softer bar as does HP.

 

[lenarenee]

Thanks lenarenee! That's helpful!

You're welcome.

 

[BattleGnome]

I find a longer cure is what will get you a harder bar. I’m trying to use up old pieces I have lying around and everything is so much harder than I remember. Everything I have been using lately is over a year old and I think it shows. If you can find the patience, use one bar at a time and take tons of notes. Try a 4 week cure, 8 weeks, 12 weeks... etc. or pick longer cure times if you don’t have that many bars.

 

[KiwiMoose]

I made a salt bar that was pretty gosh-darned hard. 50% salt to oils.
CO 75%
Canola Oil 10%
Apricot Kernel Oil 10%
Castor Oil 5%
15% superfat.
Recommend cavity moulds.

 

[SunRiseArts]

Usually I do not like to state my opinion, but I will make an exception

You got great advice here. Personally lately I have been making soap sort on the cheap side. I buy the Walmart shortening that is made with animal fats, which is tallow and palm, then I add my coconut oil, and a high oleic or a butter like cocoa or shea. I use the shortening at 55% or even more.

Cured 3 months, is the hardest bar I have experience. Adding salt to the water, might make it even harder, but I have not tried that.

 

[DeeAnna]

The "hardness" number in Soapcalc is a measure of the physical hardness like a rock. It's the total % of saturated fatty acids in the recipe (stearic, myristic, lauric, palmitic). The insolubility of a soap is related to just the % of palmitic and stearic acids in the recipe -- the "longevity" or "long lasting" number in some calcs. So if you want a hard and longlasting soap, it should be higher in palmitic and stearic acids.

There are other ways to add physical hardness besides adjusting the fatty acids. Topofmurrayhill, a member who doesn't post here anymore, found that using vinegar (acetic acid) measurably increases the hardness.

 

[dixiedragon]

5% beeswax
5% castor
45% lard
20% coconut
25% olive, ricebran and sunflower

10% beeswax is definitely too much and will make a softer bar!

 

[zanzalawi]

Usually I do not like to state my opinion, but I will make an exception

You got great advice here. Personally lately I have been making soap sort on the cheap side. I buy the Walmart shortening that is made with animal fats, which is tallow and palm, then I add my coconut oil, and a high oleic or a butter like cocoa or shea. I use the shortening at 55% or even more.

Cured 3 months, is the hardest bar I have experience. Adding salt to the water, might make it even harder, but I have not tried that.

it is inexpensive but it makes such a lovely bar!

 

[Dean]

Usually I do not like to state my opinion, but I will make an exception

You got great advice here. Personally lately I have been making soap sort on the cheap side. I buy the Walmart shortening that is made with animal fats, which is tallow and palm, then I add my coconut oil, and a high oleic or a butter like cocoa or shea. I use the shortening at 55% or even more.

Cured 3 months, is the hardest bar I have experience. Adding salt to the water, might make it even harder, but I have not tried that.

What's the calc hardness factor?

 

[penelopejane]

The soap calculators will not take into account the hardness that salt or vinegar brings to a bar so the “numbers” are irrelevant for those soaps.

 

[Madelyn Cole]

Thanks everyone! Is the salt added to the lye/water? Any special kind of salt?

 

[penelopejane]

Thanks everyone! Is the salt added to the lye/water? Any special kind of salt?

Add the salt to the water before the lye or it doesn't dissolve.
Use salt without iodine or anti-caking agents.
Don't use himalayan pink salt in soap even as a decoration on top because it is lethally scratchy - can draw blood. Even if it is dissolved it seems to retain the scratchy element.

 

[Zany_in_CO]

Thanks everyone! Is the salt added to the lye/water? Any special kind of salt?

Hi Madelyn,
Here's what I do and I quite like the texture of the finished soaps::
1) MAKE FAUX SEAWATER - I make up a quart at a time and store it in the fridge until I need it. Use for water portion of the lye solution.
1 quart warm water
1 Tablespoon sea salt
1 Tablespoon sodium bicarbonate (baking soda)

I fiddle around with the "Water to Lye Ratio" Option on SoapCalc to come up with the right amount of hardness to suit my preference. Note: Every soap is different so there's no One-Size-Fits-All. Here's a example from my "No Slime Castile" Recipe:

2) MAKE LYE SOLUTION - Mix and allow to cool to 35°C - 40°C (100°F - 110°F).
1.7:1 Water to Lye Ratio
0% Super Fat

I’ve tried 2:1 and 1.5:1. 1.5:1 gets almost too hard and 1:2 is okay but a bit slimey, so for me is 1.7:1 is the ideal. Olive oil is high in unsaponifiables; so 0% SF works best to reduce slippery slime.

HTH (Hope This Helps! )

 

[Dawni]

The liquid in the recipe above makes a hard bar as well, even when using soft oils, since that was what your query was about ^^

I just don't know what number the hardness is because those calculators only factor in the oils not what's in the water, just like @penelopejane said about salt and vinegar.

 

[melinda48]

it is inexpensive but it makes such a lovely bar!

I don’t think it needs to contain expensive ingredients to be good soap.

 

[Madelyn Cole]

Thank you everyone! I'll give salt a try!