# Why are some soaps hard?



## snoozy (May 10, 2002)

I bought some goat'smilk soap and I have noticed that this particular soap is extremely longlasting. Unlike a lot of handmade soaps, which are soft and practically melt away, this one is -- even now when it is down to an absolute sliver-- hard and not brittle, not bendy or losing its "integrity", shall we say. 

What makes a soap hard or soft?


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## linn (Jul 19, 2005)

It may have contained a majority of hard oils. The maker may have also included sodium lactate or stearic acid. It was probably also well cured.


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## MullersLaneFarm (Jul 23, 2004)

It could be a couple of things. 

Various oils contribute to how hard and how long the soap will last. As does the amount of liquid used in the lye solution and just as important ... how long it had been since the time it was made and the time it was used.

In the past 14 years, I've seen the 'cure' time go from 8 weeks to 6, to 4, to 2 ... all justified by the soap maker for one reason or another.

The 'cure' time DOES make a difference in how long your soap will last because excess liquid is evaporated out. I'm betting that this bar of soap also has a real nice lather to it. Just another bonus for long cure times.

Soaps using AO (animal oils) seem to last longer than an all vegetable oil soap ... unless the soap maker is using a hydrogenated vegetable oil.


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## snoozy (May 10, 2002)

Thanks. So the cure time -- will any soap become harder if you just store it?


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## Tinker (Apr 5, 2004)

Yes, all soap should get harder with age. However, the recipe you use is important too. An aged batch made with mostly solid oils will end up harder than a batch made with mostly liquid oils. There are exceptions, as a 100% oilve oil soap will be so hard in 24 hours it may be difficult to cut. But as a rule, it is a bit slimey, and dosen't usually last a long time.

So, in considering final hardness, oils, lye discount, water discount, and cure time are all factors. Oher additives such as fragrence & color can affect final outcome too.


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