Water Loss question

David08848David08848 Member
in Formulating


I have a simple question about this formula.  At the bottom I see that it says "Note:  The loss of water is approx. 10%"  I take that to mean the formula when completed weighs 10% less of the original total weight of the formula because of the evaporation of water during the process.  I just want to make sure that it is correct and that it doesn't mean that 10% of the water phase has evaporated!

Thanks! 
David




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  • GraillotionGraillotion Member
    edited July 2021
    A formula always equals 100%....Both when putting it together, and at the end.  Therefore we add either a little extra water to begin with...say 10% (a good number) or we add it at cool down.  It would be a recipe...if the final product did not equal 100% :) 

    Since I try to minimize adding large amounts post emulsion...I add 10% additional water to my formulas (at the beginning).  I lose at least that much as most of my formulas require 80C.

    And yes....it is the water you are losing.
  • David08848David08848 Member
    edited July 2021
    I was fortunate quite a few years ago to be able to communicate with the late Maurice Hevey who was a cosmetic chemist who was on a Yahoo Cosmetic Chemistry message board and he helped many people (just as Perry does now) to understand the basics of cosmetic chemistry and the specialized characteristics as well.  I learned very early on about formulas so I am quite familiar with the 100 percent base of all formulas.  ;)

    Lathering Shaving cream became quite popular starting in the 1920's and the formulas and ingredients lists from those times are still exactly the same on current products as they were back then because they work well!  There are quite a number of books that contain formulas for this type of shaving cream dating back to that time especially in the 20's, 30's and 40's and they either can be found in cosmetic chemistry formula books or soapmaking textbooks.  Cosmetic Chemistry procedure has changed greatly in the last 100 years so it is not unusual to look back at an old book and find some procedures that are now questionable.  That is why I asked the questions I did. 

    I haven't noticed any current formulas (for any kind of products) that mention having an evaporation percentage but I have seen some that say you should add back any of the evaporated water to the batch of that particular product.  Also, the procedures listed in these old books such as stirring something on heat for a certain period of time would cause evaporation so I am now looking at the production procedures from some of these old formulas to see if they have techniques like those listed! That tells me something about that formula and answers the questions as to why some of the old formulas have larger water phases than the others!

    Because my batches are relatively small, I can easily add the amount of water that evaporated, the next day and homogenize it.  A large production company probably can't do that quite as easily as I can.  So it would behoove them to have a larger water phase to account for the water loss during their production which is why some of these old formulas have larger water phases. Because of this, it will tell me what size water phase I need in creating my formulation.  So the formulas with procedures in them can tell me quite a bit more about them than those without!  Obviously comparing phase size, ingredients and procedures can as well! Having this knowledge helps me to understand which old formula will be more helpful to me to create a new formulation!

    Also, I did know that it was the water that was evaporating in the formula because none of the other ingredients have the ability to evaporate I just needed to know if it was 10% of the total formula (not the water phase) and if they had written it this way I wouldn't have felt the need to just verify what I thought all along!  - "Note:  The loss of water is approx. 10% (of the total formula)"

    Thanks!


  • chemicalmattchemicalmatt Member, Professional Chemist
    @David08848 Sounds like you solved your questions already. That is a classic Old School shave cream formula there. I want to thank you for reminding of the late Maurice Hevey. I met him once at a conference (he resided in the Twin Cities I think) and was an outstanding human being as ever there was, not to mention a superb cosmetic chemist. Nice memory there! 

  • suswang8suswang8 Member
    Novice here, but I want to add $0.02:

    I was given the advice from here of adding in an extra 10pct as a ballpark for any hot process formulation to account for water loss due to evaporation. 

    In general, I think this is good advice, and I have put it to use, however:  it really depends on how hot you are heating things and for how long.  I typically only add an additional 5pct if I'm only going to 60-65 C.  (For the above recipe, I would be surprised that only 10pct water is lost, especially if one is heating Phase B (water) to 90 C uncovered.) 

    I really cannot tell from the above recipe if they are just mentioning that you will lose 10pct water, or if they are instructing you to add in an additional 10pct.  Perhaps someone else can say for certain.
  • David08848David08848 Member
    chemicalmatt,  Maurice was also a member of a board called "The Soap Dish"  where he helped and gave advice to home-crafters making soap and cosmetic type products.  I saw the value in his posts and joined his Yahoo Board where I learned as much as I could about the cosmetic chemistry approach.  Unfortunately there was someone on "The Dish" who created a problem, made him feel uncomfortable so eventually he left there and took his posts with him.  Fortunately, I had saved them and still have them to look at!  He unfortunately passed away quite a few years ago but he is still missed!  Still, I have fond memories of his help and his kindness!

    suswang8, I understand what you're saying about seeing the value of adding extra water ahead of time to cover the upcoming water loss during the manufacture of a shaving cream.  My concern is about the sizes of the water phases in various old sample formulations and the fact that evaporation is not mentioned in the procedures for making each formula.  For me it is a matter of my interpretation of a formula because only one formula so far has addressed the issue!  I can use my years of making shaving cream to determine whether a certain water phase is too high or too low, decide whether I should add extra water ahead of time or weigh the batch and add it after and go from there!  Having as many sample formulas as possible can be helpful and hopefully some patterns will emerge and help me get to the right place!  I'm close, but I have one more hurdle to get through!  Just determining the size of the Tea Stearate and readjusting the lye ratios accordingly and I'll be done!  Regarding the "Note:  The loss of water is approx. 10%" , I would think if they wanted you to add 10% of water back they would have said so.  This seems to indicate that they see the 10% water loss as part of the formula and the manufacture of that formula.  That's my take on that!

    Thanks, everyone!


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