trouble making a long lasting soap

[EmBlakey]

Ive had great success making all sorts of soaps with pretty colours and fragrances, but my biggest problem is getting a bar to last. The nasty ones I can buy in a shop all seem to last 4-5 weeks but mine only last maybe 2. I have reduced superfat to about 5% but that often results in a bar with a white residue - presumably the lye. I can harden it with beeswax, but harder doesn't seem to correlate with longer lasting. Any tips please??

 

[Dahila]

How long are you curing it? Mine is cured a minimum of 8 weeks and it lasts forever

 

[lionprincess00]

First, the residue is most likely soda ash. Higher water amounts contribute to this, as does cooler dryer curing temperatures I found. Covering for a good week with saran wrap or towels can cut down the ash a lot, as well as using a higher lye concentration.
If you think it's raw lye, you need to zap test it. Lye crystals undissolved are flat out dangerous and you shouldn't use that soap if it is in fact lye, but I'm betting it's probably the ash.

You need a good 4 weeks cure on soap, but I find 6-8 weeks is best.

If you post your recipe with water amount (important), cure time, and method of storing the soap we can troubleshoot. By the way, once you post these figures, I can show you a neat trick I learned on here for determining your bars lasting power.

 

[The Efficacious Gentleman]

Did you see the other post about hardness/longevity? Basically your hardness value minus your cleansing value is an indication of how long lasting the bar will be.

 

[lsg]

Is your soap draining properly in the soap dish or shower? Well drained soap lasts longer.

 

[nebetmiw]

I would ask that you post your recipe. If you are not using AO then that with hardness could be why. I know with our water type veggie oil soap doesn't last at all. We have hard high ph water plus high humidity.