Home Cosmetic Science Talk Formulating General Science Soap Sweat

  • Soap Sweat

    Posted by leather_suds on February 12, 2020 at 9:27 pm

    Besides modifying the fatty acid ratios during saponification to control the final glycerin content of traditional NaOH soap, is there anything else I can do to mitigate sweating.

    I have a formula that is sweating like crazy.
    My customer wants a very high additive/frag % (2.5%) content in a paper wrap and I need to figure out if there is any way to reduce the sweating. As is, my formula is damaging the wrap and I need to avoid that.

    Changes in the soap base are out of my control at the moment, I am limited to additives. Is there anything that will counteract the effect of glycerin? 

    I know how past certain temp & humidity point soap will inevitably sweat. 
    I have added clays & cornstarch trying to retain the moisture, any other ideas are welcomed. 

    I would ideally just tell my customer to keep the soap in a controlled environment at all times but yeah, don’t think that’s gonna fly. 

    Thank you 

    belassi replied 4 years, 1 month ago 2 Members · 5 Replies
  • 5 Replies
  • belassi

    Member
    February 13, 2020 at 12:42 am

    This is one of the reasons I gave up making CP soap except for personal use. I was never able to fix that problem. 

  • leather_suds

    Member
    February 13, 2020 at 10:07 pm

    Thank you for commenting Belassi, I was actually hoping you would weigh in.
    If I may ask, did you ever come close to making a difference? even a small reduction will help me… 

    did you ever try clays, cornstarch, making it harder with stearic acid…
    and I wonder if Syndet bars have this issue…  
    I am even thinking on adding a pack of SiO2 to my box to see if that might help… 

  • belassi

    Member
    February 13, 2020 at 11:47 pm

    I’ve made all sorts of experiments with CP soap. Clays, yes, produce good ‘slip’ but cannot be used in much % or the bar becomes brittle. Cornstarch no, because I think the high pH would turn it brown. Stearic acid, only with HP soap because the reaction runs away and ‘rices’ with CP.
    You can look up the saponification factors for the different oils and try to choose ones that liberate less glycerin, but, this limits your combinations and you may not produce a soap with the desired characteristics.
    Climate has a noticeable effect. In winter I had little problem due to low humidity. When humidity is high, the glycerin absorbs water vapour and the soap sweats unpleasantly. For me, storing stock in sealed packages wasn’t desirable either.
    Syndet bars avoid this problem. Of course, we don’t have a ten-ton press handy to mould the bars!
    So now I just make HP soap for the family. Although I don’t use it myself. I prefer synthetics.
     

  • leather_suds

    Member
    February 14, 2020 at 2:12 am

    I’m about to try cornstarch… 
    I’ll share my results either way… somebody shared with me how the presence of citric/citrate seemed to exasperate the sweating effect even more than normal… I was using citric acid as my chelate for this formula but now trialing with sodium glutamate diacetate instead. I’ll probably collect some data on the results next week. Thank you for your input and ill let you know how it turns out. 

  • belassi

    Member
    February 14, 2020 at 3:27 am

    You cannot lower the pH. Citric acid is death to CP soap.

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