Making a harder bar of soap

[fruit.tart]

Hi everyone! After a long hiatus, I'm venturing back into soapmaking. The benefit of my time away has allowed me to really judge some very fully cured bars of soap I created last year, and now I want to improve on them.

 

I use an olive oil, coconut oil, shea butter, and castor oil blend for my soaps. I like this blend for how easy it to unmold and how it feels in the hand when being used, good lather, hard but not too hard that if I dropped it, an edge would chip off etc. However, while it's perfect consistency for my tastes as a shower bar soap, it fails pretty spectacularly as a hand soap when it's constantly being used all day long. It ends up like a soft mush by the end of the day. Ultimately, I'd like to create a recipe that works as both a hand and body bar.

 

Does anyone have tips on how to make for a harder bar? Would I need to explore using other oils (like palm) to achieve the consistency I want? Thanks in advance!

[TallTayl]

Welcome back to the craft 🥰

 

Your instincts are spot on. Palm or lard will provide the texture you’re after. You can try adding  stearic acid, which can become tricky to keep from developing stearic spots and accelerating. 

[NightLight]

Add sodium lactate, or pure soy wax. You will love sodium lactate! Do a google. A small amount of beeswax is good to 1 percent, this also prevents ash.

[fruit.tart]

18 hours ago, NightLight said:

Add sodium lactate, or pure soy wax. You will love sodium lactate! Do a google. A small amount of beeswax is good to 1 percent, this also prevents ash.

Ah yes! Thank you for reminding me that I have a new container of sodium lactate for this very reason. Will try it out!

 

I have another question though on these one-year old soaps...almost all the bars I created have this yellowish discoloration. What might be the cause of this? Is there any way to avoid it? These bars were left out on a shelf in the garage for a very long cure! 🫣

[TallTayl]

That's oxidation, like rust, on soap. It may have been exposed to some metal. Or some of the oils in the formula were shorter shelf life than what that soap required. Oils like canola, almond, soybean, etc "rust" quicker than Palm, coconut ,etc.

 

Orange dots/spots on soap are often called DOS - Dreaded Orange Spots.

[fruit.tart]

25 minutes ago, TallTayl said:

That's oxidation, like rust, on soap. It may have been exposed to some metal. Or some of the oils in the formula were shorter shelf life than what that soap required. Oils like canola, almond, soybean, etc "rust" quicker than Palm, coconut ,etc.

 

Orange dots/spots on soap are often called DOS - Dreaded Orange Spots.

 

Ahh wow I did not know of this! I'd never cured soap for this long without using before, such a good learning experience haha.

 

I'm fairly certain the oils I used when I made the soap were fresh. Could it possibly be trace metal exposure from the fact that I used tap water instead of distilled?

[TallTayl]

1 hour ago, fruit.tart said:

 

Ahh wow I did not know of this! I'd never cured soap for this long without using before, such a good learning experience haha.

 

I'm fairly certain the oils I used when I made the soap were fresh. Could it possibly be trace metal exposure from the fact that I used tap water instead of distilled?

 could be a number of things:

short shelf life oils like grape seed, canola, etc will often dos even when freshly opened as the hydrogen bonds in soap just lend the molecules to oxidation.

 

could be proximity to metal dust, use of metal utensils, etc.  could be the fragrance oxidized. Could be it got hot/humid or exposed to sun too much. Could be impure olive oil.  Olive oil is one of the most adulterated of the oils, often cut with canola or soybean.  I had soap turn completely orange from adulterated “pure” olive oil from a grocery store. Hard lesson for sure!
 

trying to remember the soap golden rule to minimize the potential for dos.  Pretty sure the combined Linolenic Acid total in the formula needs to be less than 15. 

[TallTayl]

As for hardening, what we usually mean is solubility,  additives like sodium lactate make the fresher bars feel “harder”, but do not change the way the soap wears with use because the fatty acid profile of the oils used are what they are.  
 

Solubility means how fast the soap softens or wears away during use.  We can all agree that a cured olive oil soap is “hard” enough to leave a mark if you threw it at someone.  We also all have experienced that the same olive oil soap turns to mush more quickly than other oils when exposed to water.  Sodium lactate can’t make a weak number in the solubility category magically wear longer.  Sodium lactate can just make that soap easier to package sooner without smearing or denting. 
 

oils with more stearic acid, like cocoa butter, palm oil, etc. will naturally wear more slowly than olive oil, canola, etc. regardless of popular additives.  palm and lard are used in soap formulas worldwide for long wearing soap for a reason 😊.

[NightLight]

Those spots rancid oils. Add like 1/2 tsp sodium citrate per pound. Look up edta. Many oils prone to this as TT says canola and soybean oil. Salt also hardens but also cuts lather. Use ONLY distilled water for your soap.

[fruit.tart]

On 4/28/2023 at 2:41 PM, TallTayl said:

As for hardening, what we usually mean is solubility,  additives like sodium lactate make the fresher bars feel “harder”, but do not change the way the soap wears with use because the fatty acid profile of the oils used are what they are.  
 

Solubility means how fast the soap softens or wears away during use.  We can all agree that a cured olive oil soap is “hard” enough to leave a mark if you threw it at someone.  We also all have experienced that the same olive oil soap turns to mush more quickly than other oils when exposed to water.  Sodium lactate can’t make a weak number in the solubility category magically wear longer.  Sodium lactate can just make that soap easier to package sooner without smearing or denting. 
 

oils with more stearic acid, like cocoa butter, palm oil, etc. will naturally wear more slowly than olive oil, canola, etc. regardless of popular additives.  palm and lard are used in soap formulas worldwide for long wearing soap for a reason 😊.

 

Would you recommend, as another way of getting a harder bar, a strong water discount if I don't want to change my oil blends? Would there be any downsides to doing this besides my mixture coming to trace more quickly?

[TallTayl]

1 hour ago, fruit.tart said:

 

Would you recommend, as another way of getting a harder bar, a strong water discount if I don't want to change my oil blends? Would there be any downsides to doing this besides my mixture coming to trace more quickly?

A water discount only makes the soap easier to package more quickly.  It would not change how the soap reacts to being exposed to water.  The water introduced the soap during use will still soak the bar and be the same as it is now after a use or 2.  
 

if you desire a longer lasting bar that resist turning to a mushy lump with normal use, that is a job for oils/butters/fats that obtain more “durable” fatty acid profiles.

 

Think about a stack of paper.  A tightly bound ream of copy paper is hard as can be, but will swell and soften to mush when exposed to water.  That’s like oleic acid.
 

A stack of plywood is more resilient than thin paper. that’s more like stearic. Oils with higher % stearic are sturdier when exposed to water than oils high in oleic.

 

balancing the two will give a long lasting bar that bubbles and is gentle. Commercial soap typical uses high %  of palm oil because it performs like people  expect soap to perform.