Alternative to "zap" test?

Discussion in 'Lye-Based Soap Forum' started by Sunkawakan, Sep 10, 2009.

Help Support Soapmaking Forum by donating:

  1. Sep 10, 2009 #1

    Sunkawakan

    Sunkawakan

    Sunkawakan

    Well-Known Member

    Joined:
    Sep 1, 2009
    Messages:
    229
    Likes Received:
    0
    Location:
    Colorado
    I'm obviously very new to soapmaking so please forgive my ignorance. Here goes... is there an alternative to the "zap" test to see if the lye is cooked out - is this what the zap test is for? I'm really not thrilled with touching my tounge to lye (or am I misunderstanding the "zap" test).

    I think I'm over cooking my soaps in cphp process and would like to fix the problem if possible.

    Any help would be appreciated.
     
  2. Sep 10, 2009 #2

    TheSoapyEwe

    TheSoapyEwe

    TheSoapyEwe

    Well-Known Member

    Joined:
    Jul 25, 2009
    Messages:
    307
    Likes Received:
    0
    Location:
    SW Missouri
    Some use ph strips to test but I've read and heard that those aren't always accurate.
    The "zap test" isn't as bad as it sounds, when you think your soap is ready(the vaseline, mashed potato stage) take out a small amount, let it cool and just barely touch the tip of your tongue to it if it zaps cook for a while longer (10 minutes)and then repeat.
    I like the zap over the ph because with the tongue test there is NO doubt it's out, you either get zapped or you dont:)
     
  3. Sep 10, 2009 #3

    Guest

    Guest

    Guest

    Guest

    I haven't heard of any other 100% sure way to tell , other than the zap test . You can moisten your finger , rub it on the soap and then touch it to your tongue . Most times I keep a glass of water and rinse my mouth out . You will most likely not get zapped often , if ever, but you do need to know if that soap is lye heavy before you give it away or sell it .
    There are probably some kind of expensive ph meters out there but I would prefer to be 100% positive it is not lye heavy . Your tongue can't misread or miscalculate .

    Kitn
     
  4. Sep 11, 2009 #4

    IrishLass

    IrishLass

    IrishLass

    Staff Member Admin

    Joined:
    Feb 12, 2008
    Messages:
    15,854
    Likes Received:
    9,548
    Location:
    Right here, silly!
    The zap test is very easy, quick, cheap, and 100% accurate and it will not hurt you in spite of how creepy it sounds. :) If you do get zapped, a quick swish of your tongue in a glass of water is all you need to get you on your way. It's helpful to remember that you are not sticking your tongue to full-on lye when you do the zap test, for the lye has been greatly diluted already by the oils.

    The only other ways to test for lye heaviness are properly calibrated pH meters (very expensive and a hassle to use because you have to make a liquid solution out of your soap first to get a proper reading), or a chemical called phenolphthalein which turns pink if the pH is too high. It, too, is also tricky and cumbersome to use because you have to make a liquid solution of your soap first before adding the phenolphthalein to it in order to get an accurate reading. You can't just put some drops of it on the soap directly. The tip of your tongue is so much easier and it's over in 1 second.

    The pH strips are notoriously unreliable and not recommended by most soapers because of their inaccuracy in testing soap. If you use pH strips and get a reading of anything below 9.5, your strips are lying to you. The pH of properly made and cured lye soap will always fall between about 9.5 to about 10.5. Any higher than that means they are lye heavy.

    IrishLass :)
     
  5. Sep 11, 2009 #5

    Sunkawakan

    Sunkawakan

    Sunkawakan

    Well-Known Member

    Joined:
    Sep 1, 2009
    Messages:
    229
    Likes Received:
    0
    Location:
    Colorado
    Thanks, everyone - I give - I'll do the zap test. Ok, being a newbie I beg forgivness at the stupid questions here. What does being "lye heavy" mean and what are the consequenses (will I burn someone? am I wasting soap?, does it effect smoothness, etc)? Why is this important?

    I have a feeling I'm over cooking my cphp soap but when I use it (usually while I'm cleaning up and then the day after its made when it lathers a bit better) it feels nice on my skin.
     
  6. Sep 11, 2009 #6

    TheSoapyEwe

    TheSoapyEwe

    TheSoapyEwe

    Well-Known Member

    Joined:
    Jul 25, 2009
    Messages:
    307
    Likes Received:
    0
    Location:
    SW Missouri
    Lye heavy means your soap still contains active lye, and yes it could burn yourself or others.
    Why do you feel you're overcooking your soap?
     
  7. Sep 11, 2009 #7

    Deb

    Deb

    Deb

    Well-Known Member

    Joined:
    Jul 13, 2009
    Messages:
    395
    Likes Received:
    0
    I use ph paper as I find them very accurate, and I don't like the idea of sticking a possible poison (lye) in my mouth, nor the idea of getting burned by it. Ouch!
     
  8. Sep 11, 2009 #8

    cleanwater

    cleanwater

    cleanwater

    Well-Known Member

    Joined:
    Apr 13, 2009
    Messages:
    113
    Likes Received:
    2
    Location:
    Portland, OR
    Just an fyi: lye isn't poisonous. It's caustic, it can cause serious burns, and it should be treated with serious respect, but it isn't poison. In fact, if you mix it with an equivalent amount of hydrochloric acid (another thing with a lot of burn potential) you get simple salt water.
     
  9. Sep 11, 2009 #9

    donniej

    donniej

    donniej

    Well-Known Member

    Joined:
    Aug 7, 2008
    Messages:
    924
    Likes Received:
    8
    Location:
    Philadelphia, PA
    You can use phenolpthalein or turmeric. I've done write ups on how to use turmeric, phenol is also very common.......


    Soap is a little tricky to test becuase PH is a function of water. Bar soap doesn't contain enough water to really have a true PH.
     
  10. Sep 11, 2009 #10

    donniej

    donniej

    donniej

    Well-Known Member

    Joined:
    Aug 7, 2008
    Messages:
    924
    Likes Received:
    8
    Location:
    Philadelphia, PA
    In fact the Norwegian make fish with it :D

    See "Lutefisk", or "lye fish"...
     
  11. Sep 11, 2009 #11

    IrishLass

    IrishLass

    IrishLass

    Staff Member Admin

    Joined:
    Feb 12, 2008
    Messages:
    15,854
    Likes Received:
    9,548
    Location:
    Right here, silly!
    It's used to get that shiny sheen on pretzels, too, and they use it to cure olives as well.

    IrishLass :)
     
  12. Sep 11, 2009 #12

    andreja

    andreja

    andreja

    Well-Known Member

    Joined:
    May 5, 2009
    Messages:
    134
    Likes Received:
    0
    Okay, I asked many times already, but maybe I will get the answer here. :) So, for phenolpftalein, if it has pH that is less than 8.2, it will be colorless, if more than 10, it's red. So, if in between is pinkish, right? So, I would say, not that useful, because the range of pH of handmade soap falls between 9.5-10.5, right? So, one would get some shade of red or pink when the soap is okay, and if pH is between 10 and 10.5, one would get red color, which is still in range of soap that's not lye heavy, right? So, how would you know, if it's lye heavy or just in higher end of being alkaline? I think for turmeric it's similar thing regarding pH range. Phenol red is even less useful because of the PH range it covers.

    So, can anyone educate me further? Am I mistaken where pH of homemade soap should be?
     
  13. Sep 11, 2009 #13

    IrishLass

    IrishLass

    IrishLass

    Staff Member Admin

    Joined:
    Feb 12, 2008
    Messages:
    15,854
    Likes Received:
    9,548
    Location:
    Right here, silly!
    I was just reading about this on another forum where we have a handful of soapers with chemistry backgrounds and here is what I found out:

    You are not mistaken as to the pH of handmade soaps. :) According to repeated tests done in the lab with accurately calibrated pH meters on fully cured soaps with a variety of superfats, they always fall within a range of 10 to about 10.5. There was some dispute with some saying they could get a reading of 9.5, but it was agreed that anything below 9.5 was definite horse pucky. :wink:

    I also read where Phenolphthalein was very tricky to use because it only works accurately in a solution. I also learned that it's a weak acid and prone to fading, so caution must be used to get accurate readings. To make a 1% solution for testing, you must melt 1 gram of soap in 99 grams of water. You'll get false readings if you use it just by dropping some on dry bars of soap as well as wet bars of soap. It must be in a solution. It was recommended to test some other things with it that you knew the pH of beforehand so that you would know what shade of pink to look for with your soap solution sample.

    Dark orange for high acid
    Colorless for up to 8.2 pH
    Pink for 8.2-12 pH
    And again colorless for 12 pH

    Seems like too much of a hassle to me to use, especially when you've got the instant and 100% accurate zap test at your disposal. :)

    IrishLass
     
  14. Sep 11, 2009 #14

    Guest

    Guest

    Guest

    Guest

    I'm curious what makes you think you are overcooking your soap. What signs are there that the soap is overcooked?
     
  15. Sep 11, 2009 #15

    Sunkawakan

    Sunkawakan

    Sunkawakan

    Well-Known Member

    Joined:
    Sep 1, 2009
    Messages:
    229
    Likes Received:
    0
    Location:
    Colorado
    Because its really crumbly. I cook it and stir it seemingly forever (up to an hour - cphp) and it never gets out of the applesauce stage. This is using tallow (homemade using salt in the process), and olive oil and/or tallow, olive oil and lard. Maybe I'm not cooking it LONG enough???? Maybe its the salt in the tallow?

    I did a batch with just OO and lard and it mashed potatoed out nicely but the tallow batches crumbled some though the longer they sit the less crumbly they become but they aren't smooth like the oo/lard bars.

    Suggestions? Either way, I appreciate all of the information and help that everyone here has give me! Sincerely, thank you.
     
  16. Sep 11, 2009 #16

    andreja

    andreja

    andreja

    Well-Known Member

    Joined:
    May 5, 2009
    Messages:
    134
    Likes Received:
    0
    IrishLass, thanks for the great info!! I have chemistry background too. :wink: It seems to much hassle to me too, using any of those pH indicators.


    To the original poster. I didn't do many HP batches, but the ones that I did were crumbly too. Batches were I was able to quickly move to the mold and press it down weren't crumbly. As for stirring, are you using stick blender?

    I really find CP so much easier. You can do CPOP (you force gel in oven, so it's mixture of HP and CP, but done in the mold).
     
  17. Sep 12, 2009 #17

    Maria

    Maria

    Maria

    Well-Known Member

    Joined:
    Oct 26, 2008
    Messages:
    300
    Likes Received:
    0
    Location:
    Lighthouse Point, FL
    My soap is only crumbly when it is over cooked. When I cook the soap and it bubbles trying to climb out of the pot, the bubbles are big. The next stage, the bubbles are flatter and no longer try to climb out. I do the zap test then and it is almost always ready to go.
     
  18. Sep 22, 2009 #18

    Guest

    Guest

    Guest

    Guest

    I found "sort of" an answer today in Catherine Failor's book, "Transparent Soapmaking."

    An alternative to the zap test is to dissolve a bit of soap in a small glass of water. The soap dissolves. The fat floats on top. Ideally, when no fat floats on top, the soap is neutral.

    So, if one saved their SF to add after no-zap, that test would work.

    If you already have the SF in the recipe, this test is no good -- you wouldn't be able to tell the unsaponified fat from your SF.
     
  19. Nov 2, 2009 #19

    Absinthe

    Absinthe

    Absinthe

    Well-Known Member

    Joined:
    Oct 28, 2009
    Messages:
    278
    Likes Received:
    1
    Do not be afraid of the zap test. If the soap is solid at all you have used up most of the lye anyway. The amount you are going to get by lightly touching the tip of your tongue to it is so minuscule that your saliva alone should neutralize it. Remember the reason you can buy food grade lye is that it is used for cooking. Hominy is lye treated corn, lutefisk (sp) is lye treated fish, many baking items are brushed with a lye solution the list goes on.

    There is an electrolysis process for removing rust that involves running electrical current through the rusted item in a lye solution not too much weaker than the one we used for soap. I have hand my hands in it directly without gloves and I have handled the tools still wet with the solution. I have had plenty to time to walk to the sink and rinse off with not so much as an itch (usually how I know I have gotten it on me, starts to itch then well I never let it get past the itch, I saw fight club too :) )

    I don't recommend this and generally try not to get it on me at any dilution. It does dry the heck out of my skin too. I am just giving this example to show that although it is dangerous full out, the residual amount left in soap which is not fully cured yet is not so much so.
     
  20. Nov 2, 2009 #20

    Deb

    Deb

    Deb

    Well-Known Member

    Joined:
    Jul 13, 2009
    Messages:
    395
    Likes Received:
    0
    I use ph strips and i'm very happy with them.
     

Share This Page