“Superfatting and Lye Discounting, Part I” presented by Dr. Kevin Dunn.

“Superfatting and Lye Discounting, Part I” presented by Dr. Kevin Dunn.

In order to prevent overly alkaline soap, some soap makers calculate the amount of lye needed and then “discount” it by a certain percent. That is, they use less lye than is needed for the available fat. Other soap makers add extra fat (superfat) at trace with the expectation that this fat will remain in the finished soap. That is, they use more fat than is needed for the available lye. Is there a difference between these two practices?

 

KEVIN DUNN – 2015 RETREAT - PART ONE

KD	Last time someone mentioned to me that I didn’t have to dress so formally for this group.
A	Laughter
KD	So we are going to be talking about lye discounting and superfatting today.  What does that mean?   What does it mean lye discounting?
A	It’s the same as superfatting.  Just some fat won’t saponify.
KD	I’m using both terms because it’s a real, somebody asked me one time is it the same thing.  So we’re going to find out if it’s the same thing.  I want to thank Mike Lawson, Columbus Foods.  He’s been a great supporter of our work.  They have donated all the oils for our research for many years.  Derek Hodge is also stepping into that camp, he is donating materials for our research and, of course, putting on the event here.   These are all Hampden-Sydney College students who worked on the projects.  When I do research there are students who I give assignments to and they get to turn the screwdrivers and mix the soap and I’m the big idea man.  So I want to recognize these guys.  All right, so a little review from last time we talked about oil and water don’t mix and this is an example of an oil molecule and you will notice that is what color?
A	Green
KD	Green, now I talked last time about the difference between polar and nonpolar molecules.  Green molecules in this color scheme are which ones?  Polar or nonpolar?
A	Nonpolar
KD	Nonpolar, and at the bottom I have two water molecules, they are red and white and red and white means?   
A	Polar
KD	Polar and the red and white molecules are attracted to one another, because opposite charges attract.  I talked about nerds and cheerleaders last time so this is just review.  Somebody tell me the parable of nerds and cheerleaders.  I probably can’t do that for the microphone, but in dining rooms all over the world in high schools, cheerleaders are sitting at the same table.  Why are they sitting at the same table, is it because they hate the nerds? 
A	No
KD	No, they don’t hate the nerds, they just, they just like the cheerleaders better than the nerds, so the cheerleaders all sit together and the nerds are left to sit wherever the cheerleaders aren’t, wherever there is room to sit.  So we call the green greasy molecules lipophilic, that’s fat loving and the red and white molecules are hydrophilic or water loving.  This is what an oil molecule looks like for us.  It looks like three fingers connected to a knuckle.  And I have three hydroxide ions there, what color are they?
A	Red 
KD	Red and red means?
A	Polar
KD	Red and the white are two different charges.  The red is negative and the white is positive.  In this case it’s red and green because it's not very positive at all.  The whole thing is a hydroxide ion which is negative.  All right, so this is what happens, you can make the noise with it, ping.  What happened is the first hydroxide ion has come in and attached itself to one of these fingers and cut it off.  So I’ve got now one molecule that has two big bright red eyes on it, the red eyes mean what? 
A	Negative
KD	 What charge, negative charge.  This is a molecule that is negative at one end and has green and greasy and lipophilic at the other end.  I still got a glom there where I still have a knuckle with two fingers left on it.  There it went dink and another one came off and I got the second soap molecule that's come off.  I still got now one finger connected to a knuckle and one hydroxide on the left, dink, there it goes and I got three soap molecules and a glycerin molecule.  The glycerin molecule is the knuckle that was down inside where the three fingers were attached.  Am going too fast, this is review?  Okay.  All right, so now we are going to look in detail at that soap molecule, the one that’s got the two red eyes at the top.  Very negative at one end.  The red negative end is going to be attracted to what, oil or water?  It is going to be attracted to water and the green greasy end is going to be attracted to?
A	Oil
KD	And that’s the way soap works.  If you see a soap molecule that has got a bunch of water molecules at, we call it the head end or the hydrophilic head attracted to water molecules and that white atom in the center there is the sodium ion that is left over from the sodium hydroxide.  We call that amphiphilic.  Philic means what?  If I’m an anglophile means loving English.  Philic means “love”.   Amphi mean “swings both ways.’  
A	Laughter
KD	So this is a molecule that is comfortable, both in an aqueous watery environment and in a greasy environment. All right we are going to talk about fatty acids today so I want to give you a look at those.  These are fatty acids, they are saturated fatty acids and they come in different lengths and depending upon how long the tail is, the head is the red and white end and the tail is the great great green greasy end and if you look at it that looks kind of like the soap molecule.  Remember what a soap molecule looks like, it's got two red eyes.  Here we’ve got, we sort of got, one red eye and kind of a yellowish eye, and there is an extra little white atom, that’s what makes the difference between a fatty acid and a soap.  These are the unsaturated fatty acids, they all have kinks in them.  Those kinks are where there is a double bond and the molecule curls back on itself when it’s got these double bonds. All right, here we have soap and I have added in, you can’t see in amongst the water, there is an extra hydrogen atom.  I am going to give you a synonym for hydrogen atom that’s got a positive charge and we’re just going to call it a proton.  So proton is an H+ and buried inside that glom of water molecules is an extra hydrogen atom and now I’m going to add that hydrogen atom to soap and it will make another noise, donk.   All right will do this again, dink, donk, dink, donk.
A	Laughter
KD	That's fun.  What happened was the proton which was formerly attached to the water molecule has jumped ship and has attached to the head end of the soap molecule and that has become a fatty acid molecule.  Now if you look at it, this fatty acid molecule do you think it is more or less attracted to water molecules then it was before?
A	Before
KD	So back here, look at the two red eyes, red means “negative” attracted to water molecules and now
A	Water molecules, less.
KD	Not so much, right, it’s not got as much as charge on the head end then it had before so we expect it's going to be less attracted to a water molecule.  Well we can bring it the other way, now in amongst the water molecules, I have added an extra hydroxide on it, remember that’s an oxygen with one hydrogen instead of two, dank, dank, dank, and what happens the protons jumped ship from the fatty acids, attached itself to the hydroxide ion and H+ + and OH – makes H2O, which is a water molecule, so the hydroxide ion when it absorbed the proton from the fatty acid turned into another water molecule.  All right, so we’re actually going to look at some soap now.  You’ve all got bottles of, don’t mix them up, you got a bottle that's half full of water and it should by now to be blue.  Down underneath, don’t want you to confuse this with a beverage
A	Laughter.
Susan	Britain’s got a couple of them
KD	What is this?  I had to get this through airport security so I packaged it in little travel shampoo bottles and fortunately it went right through.  They didn’t even ask me a question about it.  If they had asked me what is that, I would have said it's soap.  It is really soap.  The blue color comes from an indicator which is universal indicator.  This is like the little PH strips that you get, but it's a solution that you can add and now we don’t have to fool with test strips.  The color is going to tell us about the PH throughout our investigation.  So that color, the blue color is about a PH9. If we go to PH10, it's going to more a purple color.  If it gets down to green, that’s PH7 and if it gets to yellow, that’s going to be like PH6 or 5.  So we are just going to play around now.  I don’t know how this is going to play on the video because we’ve got stuff to look at.  But I’ve got here some vinegar and, oh, first of all, we want to see the soaps, so make sure the cap in on good and give it a good shake.  Is it sudsing up for you?  So this is soap and what I want you to do is let it sit for a moment, but when you look at it, the bubbles are going to rise to the top and you will see that the solution is transparent, you can see through it, okay.  We’ve got vinegar here to lower the PH, and I’m just going to add a drop of vinegar.   What’s that done to the PH?
A	It’s trickling down. 
KD	I don’t know, compare it. How does it look compared to yours? 
A	darker.
KD	So, I'm going to pass the vinegar around, I will give you a drop or two and just give yourself, I don't know, a couple of drops of vinegar in each bottle and shake it up again.  Can we have some cups, can I get some cups and we will have multiple vinegar bottles down here. 
A	A couple drops here?
KD	To begin with, and if you want to, I've got some more, some more droppers here.  So we are lowering the PH with vinegar.  How does it look now?
A	One changed and one didn't.
KD	It's depending on how much vinegar got added.  Okay, now this is good, let's hold these up.  So one of them looks still blue and one of them is red. 
A.	A lot.
KD	 Now shake them up.  In addition to the color what do you notice?
A	No bubbles.
KD	No bubbles, the bubbles went away. Now we're puzzling, why is that, why did the bubbles go away when I lowered the PH?    We think about the molecule, when I lowered the PH, when I added proton to the soap it became fatty acid and the fatty acid was more or less soluble in water.  Less soluble in water, so actually in the red bottle there, there is no soap left.  You have converted it entirely to fatty acid.   Okay, if you are still working on the blue bottle, let's add some more vinegar to it.  Let's get everybody, if you can see if you get to the "sweet" spot and make it green.  There we go, that's sort of a greenish color right?   So I want if you can, first look and see what happens when you get it to green.  Green is PH7 and once you get to green, keep on going and get it yellow or red.
	You got kind of a half and half thing going.  Look at the bottom and top, so give it a shake.  So this is uh, the red is higher but lower PH than the yellow is.
	Can I get some cups again?  Just two, three.  So everybody at yellow or red?   Okay, let's take it the other way, this is household ammonia.  We're going to see what happens when we raise the PH back up.   Now we've got plenty of time in this first talk session, so let's take some time with this, let's go drop wise, one drop at a time, this is ammonia.  We are going to raise the PH and see what happens as the PH goes up.  Come on up and get some.  So let's do one drop at a time and let's see how that goes.
A	As far as one and another and another?
KD	Uhmm, let's do one at a time, so everybody can see.
A	Should we shake it?
A	Do we shake in between?
KD	Shake in between, when you've added a drop of ammonia, and then give it a shake.  So the colors are, red is a PH5, yellow is a PH6, green is a PH7, blue is a PH8 or 9.     
A	I'm ready for the shot.
A	Mine's changing from pink to orange.
KD	 So pay attention as you're raising the PH, at what point, at what color, do you start to see some suds to come back?    You can probably add a couple of drops at a time now, so what you're finding out is, it takes quite a lot to move the PH. 
A	It's a darker pink now.  Oh, oh, here it goes.
 KD	It might be the difference between three and four drops, or two and three drops.  There you go, that's starting to go back where you started, right?   
A.	One's grape.
KD	 There you go, that's back to where you started, right?  Make sure your drinking from the right bottle.  Is everybody back to blue?
A	Yes
KD	What happened is I raised the PH.  What happened to the soap as I raised the PH? 
A	The bubbles came back
KD	The bubbles came back.  And I want to get very clear the difference between a fatty acid and an oil.  When you add alkali to an oil, how long does it take to turn into soap?  Like seconds, couple of seconds.
A	No
KD	No, how long does it take before your soap is set up?   Like 24 hours, it takes a long time.  This happens almost instantly as you add the alkali, it turns back into soap.  How far did you get it?   Did you get it to purple?
A	No
KD	No, in fact you're not going to be able to with ammonia, it's too weak of a base, but I do have a little bit of 10% lye here.  So here is the one that I started with, it's blue and I'm going to add just a little bit of sodium hydroxide and see if I can get it to purple.  Can I get one of the blue ones here for comparison?  So that's PH10, this is PH9 and what do you see about, let's shake it up for comparison.  Can you see it?
A	Yeah
KD	It's about an extra, wow, it's actually quite a bit more.  So I'm getting suds there, but at PH10 I got a lot more suds then I had at PH9.   So if you want to do this after class I've got the 10% sodium hydroxide here and you can see how far you can get it, but there is a move out there to acidify soap, and so I just want you to realize that you're up against it if you're trying to lower the PH of soap, what happens as you lower the PH?
A	 Less bubbles
KD	Less bubbles.  The soap turns into fatty acid and fatty acid doesn't have the same properties as soap does.  We're not turning it all the way into oil.  If we turned it all the way into oil, then it would take hours to come back, but as you see as we raised the PH, it turns back into soap almost instantly.
A	So in the case of the castile soap, is it a less soapy soap?  So that would explain that it is more of a fatty type of soap?
KD	No, you're asking me a question I don't know the answer to that.  Why does an olive oil produce as much lather as say coconut oil?   One difference is that the fatty acid chain in an olive oil is longer than the fatty acid chain in coconut oil.  Coconut oil is also saturated, so it's straight instead of crooked.  How does that affect the lather, I don't know that.  And we also shouldn't confuse cleaning with sudsing.  Here, why didn't I say "Well let's see how it cleans".  Well we all have to go into the bathroom and wash our hands and then it's a judgment call, I don't know, my hands feel pretty clean, we would be arguing about it.  But when we use the suds as an indicator of how well the soap is working, we can at least see instantly what's going on with that.  And we see that the suds and the PH track one another.  Okay what else, any other questions?
A	Does the PH alter over time once the soap is made?
KD	Yes, in fact I got four students doing advanced projects right now and two of them are working on this whole notion of what happens to the PH of soap over time and is it possible we've seen here we are up against a hard nut if we're trying to lower the PH of soap.  That doesn't mean that it's impossible, it means, I don't know how to do it and several people have asked me about adding apple cider vinegar to soap, so I've got a guy that's his whole project for this semester is looking at adding acid to soap, in particular apple cider, adding it before the soap is made, adding it after the soap is made and testing the alkaline properties of soap over time.  
Okay, the indicator that we are using here is universal indicator.  If you go on line you can probably find this.  It is not very expensive and it takes the place of the little PH test strips.   
All right, so coming back to our molecules, I'm going to use a word now, triacylglyceride, I think I introduced you to that term last time.  Triacylglyceride, tri means three, the acyl is each of the fingers is an acyl group, so it's three fingers and the glyceride means down in the core of the molecules, the knuckle where the three fingers are attached, that's a glycerin molecule.  So triacylglyceride tells you the structure of it.   Diacylglyceride is after one of the fingers has been amputated, the amputated finger became what?
A	A soap?
KD	A soap molecule and the thing that was left, we're now going to have a term for it diacylglyceride.  With a triacylglyceride, notice I said I called AAAG, that meant three acyl groups and a glyceride, Double AG is two acyl groups and a glyceride and if I go to the next step, I get to a monoacylglyceride, the hump there at the bottom is a finger that's not got the two other fingers attached, but it still's got the knuckle attached to it, so it's a monoacylglyceride.  And then finally we've got four molecules total, we've got three soap molecules and a glycerin molecule.  And look at the glycerin, what do you think its properties are, is it soluble in water or not?  Why is it soluble in water?
A	It's the red and white atoms
KD	It's got the red and white atoms.  It's got the positive and negative atoms to interact with water molecules.  All right, I'm going to introduce you to a fun new word, "Stoichiometric".  It's going to take you awhile to say it, so say it with me, "Stoichiometric".  If you use this word to a chemist, his eyes are going to light up.  What in the world this lady knows the word stoichiometric.  What does it mean?  All it means is that we want to know how much of this goes with how much of that.  And you have been doing stoichiometric ever sense you started making soap.   You need to know how much of this goes with how much of that.  What's this oil, what's that stoichiometric lye?   You need to know how much oil goes with how much lye, because you don't want to get it wrong.  If you get it wrong, what?  You've got two directions to get it wrong.  Too much lye or too much oil.  We will talk about that, but getting it just right is the word that describes that.   So I'm going to talk about the stoichiometric hypothesis, stoichiometric hypothesis is, if I start with a triacylglyceride, AAAG + 1 NaOH, that's going to make a double AG, remind me double AG is diacylglyceride and one NAA, what is that?
A	Soap
KD	That's our soap and we get a water molecule out of it.  The hydroxide attached to a proton and became a water molecule.   So if I provide one molecule of sodium hydroxide to one molecule of soap, I'm going to get a diacylglyceride.  If I provide two molecules of sodium hydroxide, then I get 
A	Two
KD	Two soaps and I'm left with a monoacylglyceride, and if I add three molecule of sodium hydroxide, I get three soap molecules and glycerin.  Let's keep going.  What if I add four molecules of sodium hydroxide?   Then I've used it all up, three of them have reacted with the triacylglyceride, amputated the fingers and I've still got a left-over sodium hydroxide.  So that notion of what's going on in soap chemistry is a stoichiometric hypothesis, three molecules of sodium hydroxide go with each molecule of oil and if I use excess sodium hydroxide, it's just left unreacted at the end.   Is that a good thing or a bad thing?
A	Bad
KD	Why is it bad?  I think, you know if I did that I would wind up with something like this and make lots of suds.  Wouldn't that be a good thing?
A	No
KD	Why not?  
A	It's harsh.
KD	What do you mean "harsh"?
A	Irritating.
KD	Irritating.  Why is it irritating? Let's think about what is that sodium hydroxide molecule going to do with your skin.
A	Burn it.
KD	What's your skin made out of?  It's going to react with your skin the same way it used to react with the oil.  You have oils on your skin?
A	Yeah
KD	So when you have excess sodium hydroxide, it's turning you into soap, which is not good.  So we would like to avoid that, we would like to avoid turning ourselves into soap, by not adding excess sodium hydroxide.   Okay, I'm going to talk about, yeah, go ahead
A	Can you go back to that screen?  So, between the second and the third formulas there, is there a preference?
KD	That's an excellent question.  I'm glad you have that question because that means you're interested in what I'm about to tell you.
A	Okay good, because one sense of just glycerin as a by-product
KD	Yeah, exactly.  So is it good or bad, we don't know.  So we will get to that.  
	In my book I talk about an alkali ratio instead of a sap value.  I talk about both but I want to have a distinction now, so that we can use two terms that are close to each other but not identical.  So if I'm talking about driving in your car, there is a thing called a speed limit.  Speed limit is a property of the road.  If the speed limit is 55, does that mean I can't go 60?
A	No
KD	If I'm going 60, does that mean the speed limit is 60?
A	No
KD	So the two things are different from one another.  The 55 mile an hour speed limit is the property of the world that I live in.  But then I get to choose, am I going to drive faster or slower than the speed limit.   So this is the same way, the alkali ratio is the thing you decided to do.  When you decided to make soap, you decided you were going to weigh out X number of grams of sodium hydroxide.  You calculated the saponification value so you would know what the speed limit is.  The number above which you don't want to go, but you still have a choice.  Do I want to drive 5 miles over the speed limit, do I want to drive 5 miles an hour under the speed limit.  So that the word I used to describe that is the alkali ratio.  And we can measure total alkali.  Last time I taught you to use the tongue test.  The tongue test is just a yes or no, do you get the zing or don't you get the zing, but we would like to get a number that we can attach to how alkaline is it.  And I have preferred to talk about total alkali rather than PH because as you saw, how much vinegar did it take to shift the PH of soap?
A	Quite a lot
KD	Quite a lot.   Soap is a natural for those of you who have had a little chemistry, it is a natural buffer.  It resists changes in PH.  So I had to add quite a lot of vinegar to get the PH down and had to add quite a lot of ammonia to get the PH back up again.  And some of you noticed, you added the same amount of vinegar or ammonia and yet your colors were different.   PH is a very insensitive measure of that.  So total alkali is what I have used because it is a very precise value and we could get hard numbers to it.  The total alkali test is describe in Chapter 15 and it measures the left-over alkali in the stoichiometric hypothesis.  Is there any excess left over sodium hydroxide in the soap.  These tests require some practice.  When you started driving, the first time you got in a car, did you make an eight hour road trip.
A	No
KD	You get in a car and you learn not to run into things and then after a while you start going a little faster, you learn to shift the gears.  You have to learn to do these things.  Chapter 15 tells you how to do this test, but just having the book doesn't make you good at it.  Being good at it only comes from trying it out and figuring out what the mistakes that I might make are.  So when I have students, I have students right now who their task this week is to test total alkali, and I know, in my heart, when we have our meeting next Thursday that they will have screwed it up.   I have a 100% confidence that while they read the book, and I wrote the book very good, very well to get the instructions just right, they will have screwed something up and the next week they will have to do it over again.   And they will have to do it over again until they get it right.  And once they've got it right, they're good at it and now they can do a total alkali test in 15 minutes.  All right, so we made eight soaps, each with a different alkali ratio.  That is, we chose to use a different amount of alkali for each soap.  I tell people that my business is making bad soap on purpose.  So these were not soaps that were designed to be given away to friends, they were designed some of them with too little alkali, some of them with too much alkali so that we can do the experiment.   We measured the total alkali for each soap after one day and eleven weeks later.   Now this is a graph of what we got.  The day old soap, if I added 140 parts per thousand, what's the number there for total alkali?
A	Less than zero
KD	Like zero, so 140 parts per thousand I had no excess alkali.  At 144
A	Zero
KD	Zero, at 146
A	One
KD	Maybe less than one even.
A	Right
KD	So if you look the scale is two, 150.  152
A	About the same
KD	153, oh look, so it was flat, I had zero left over alkali until I got to a place where I hit the speed limit and if I went above the speed limit the soap had excess alkali in it.  Now that number, the dog leg there is the saponification value.  So we could actually measure saponification values by just by making a series of soaps and measuring total alkali once they were done.  What's the saponification value for this oil?  Give me a number for it.
A	150
KD	150, that's exactly right.   I'm thorough, so I came back eleven week later and I had the same soaps, they've been curing for eleven weeks and I measured the total alkali and I got a different answer then what I expected.  What do I see?
A	Less, it dropped.
KD	Look at that, it's less than zero, it's a negative total alkali.  What does that mean if it's a negative total alkali?   What's the opposite of alkali?  It's acidic.  Now slightly acidic relative to soap, not slightly acidic as in a PH of 7, but it means that not only wasn't there, residual sodium hydroxide, there was enough acid in the bar that if I added sodium hydroxide, it would have neutralized it.  Okay, so if I look at 150, I see there is a little dog leg there, but even the soaps that were too alkaline when they were a day old are now, where do we want to get?   The industry standard for soap is less than one part per thousand alkali and even the soaps that I made with excess alkali meet that standard after eleven weeks.  Now why should that be?  What would be going on with the soaps.
A	The air
KD	The air.  Something in the air, I think, is going on with the soap and we may revisit that in a later lecture.
A	So out the gate if you have a lye dated soap
KD	Time is your friend.  Time is you friend.  Let it set out and cure and I bet you that most people when they make a lye heavy soap, if they just are patient with it, it will come around.
A	And how we do know that my soap has come around?
KD	So, you have two ways.  One I gave you last time
A	Yeah but it may not zap anyway, right?
KD	If it’s got excess alkali, it will zap you.
A	I didn't mean it like that.  Is there a zap scale?  Do you know what I mean?
KD	Yeah.   So there is kind a funny coincidence and maybe this is the reason they set it at one part per thousand but one part per thousand is about the level above which you get the zap and below which you don't get the zap.   Chemists hate me because I teach people to go around to taste soap and they're all alarmed at this terrible thing I'm doing.  I'm like the anti-Christ for chemists.  But soapmakers have been using their tongues from the beginning and it's a really good tool.   Now the alternative to that, I'm not going to advocate a PH meter because it just isn't sensitive enough.  If you want a sensitive measure to put a number, the total alkali test is what you want to do.  And it will require you a couple of hours of screwing it up and then once you finished screwing it up, you will be able to measure total alkali in about 15-20 minutes.
A	How to achieve that value of the alkali ratio, like the 140 versus, what is the difference between the
DK	It's just the amount of lye that I've chosen to use.  So I had 100 grams of oil in each one.  I can tell you in 100 grams of oil, that 140 meant I used 14 grams of lye.   For the 144, I used 14.4 grams, for the 148, I used 14.8 grams.  Remember, it's the difference between the speed limit and the speed that you chose to drive, it's how much alkali I chose to give that amount of oil.   Yeah, oh right, right, I have to repeat the questions.
DK	Okay, so I have some questions now, and these are questions that I think you have.  How quickly does lye react to oil?   And if you go out on the internet you would find out all different answers right?   Because people just make up the answers and once they made them up, they can't retreat from them.   They know that that is the answer.   So I'm going to use three terms:  cold, warm and hot.  Cold soap incubator to 50 degrees, centigrade 122 Fahrenheit, and warm soap is at 140 and hot soap is 158.  122 is typical for somebody that makes a cold process soap on the cool end.  140 is more like an hour later when you notice your soap is getting hot and 158 is more like, how many of you do hot process soap?  We have some hot process people.  When you do hot process soap, where do you process at?
A	170
KD	170, so this is getting into the hot process region.  The students measure total alkali every 15 minutes for four hours.  So this is why I have students do it.  I teach them how to do it so that I don't have to.  Okay, so this is, this graph represents an entire semester's work for two students and how long do you think there is no way I'm going to spend like four months to do this.  They spent three months learning to do it and about one lab period to actually do the experiment to get the data.   So if I'm looking at the hot soap, how long does it take to get from 100% alkali down to zero?
A	65 minutes
KD	Like an hour, right?  And for you hot process people, how long does it take you from the time you start mixing to the time that when you test it, you've got neutral soap.
A	So far close to an hour and a half to two hours.
KD	That kind of depends on how big the batch is and what the oils are in it, but we are looking at after about an hour of being hot, the soap is done, meaning that all of the alkali has been consumed and there is no excess alkali in the soap.   The warm one is more like what people do when they do cold process soap and they just let it incubate, they insulate the container and the temperature goes up.  How long is it taking them?
A	Two hours
KD	A couple of hours.  And I've done workshops at chemistry conventions where we make a soap in a Styrofoam cup and then I've become the anti-Christ because I say "All right, it's been a half an hour, let's open up your soaps and let's  taste them", and they go ahhhh, and they learn what a zing is, those of them who are brave enough to do it, but often times by the end of the work shop, by the end of the afternoon work shop they are not getting a zing from the soap anymore.
A	Because it's gone numb
KD	 Use a different part of your tongue.  After a couple of hours, the soap is done.  And in the cold one, that is if you started with a cold process soap on the cool end, where it wasn't very quick to saponify, like an olive oil soap and stayed cool, how long is it going to take?  Well we got to 240 minutes and it wasn't done yet, but I think you could probably project how long you think it is going to take.  
A	Six hours, eight hours.
KD	So after four hours it was down below 50% and if you look at the shape of the curve, it's kind of a steady downward slope, I think something like eight hours and for the most part when my students make a soap in a Styrofoam cup, when they come in the next day, it's already tongue neutral.  But that isn't what I wanted you to get out of this slide.  What I want you to get is when we reach trace, because here is another thing that people think, when it reaches trace, it's already soap.   All right, so let's imagine now how long does it take to reach trace?
A	Couple of minutes.
KD	Two minutes? 
A	Sometimes.  
KD	 Five minute? 
KD	Twenty minutes?
A	No
KD	Probably not, unless you are making something really unusual like 100% olive oil soap.  Probably has reached trace within about twenty minutes.  So let's look at the graph after twenty minutes, how much alkali is left?
A	All of it
KD	Like 75% of the alkali.  Only about 25% of the alkali has been consumed by the time you reach trace.  So, does it make sense, I see people out there in the world adding things at trace.  What do you add at trace?
A	Oils, colors
KD	Fragrances, super fat, colors.  I'm asking why you would add things at trace.
A	Sometimes you want to add different colors, so you have to divide your batch, you can't do it all at once.
KD	Okay, bring that question back as soon as we answer this one.   Why are you adding things at trace?  I know everybody knows why, why is it?
A	For example we add salt at trace because it's thicker and doesn't automatically sink to the bottom.
KD	So you have a mechanical reason.   You want suspended flakes of salt.  Most soapmaker’s that's not the answer they're going to give.  They're adding their essential oil at trace because they want to protect it from the alkali.  They are worried that the lye is going to attack their oil, their essential oil.  So I'm going to ask, what do you think about that?  How much protection is it when instead of 100% you've got 75% of the original lye?   Ahh, for myself I don't think that's really adding any protection.  So now I'm giving you permission to not add things at trace because you're afraid of the lye and you will go out in the world and say this and people will argue with you.  I'm just saying you don't have to be cowed by those people, you can say, "Well that works for me".   So there is a reason that I'm giving people permission not to add things at trace.  Why wouldn't you want to add things at trace?   Because the clock is ticking right?  You are trying to get into the mold, why are you making yourself crazy.  One is the crazy factor, you are trying to get it mixed in and the soap is hardening up and you are not going to get it into the mold and the other is how good of a job are  you going to do at mixing something in when you are under the clock?
A	Not
KD	So you may have, it looks like it's mixed in but it actually got little ribbons of essential oil running through it and it's not completely mixed in.   My thing is not advancing now.  There it goes.    
A	That's the end
KD	Oh, that's the end of part one.  So we will pick up in the afternoon and in the meantime when we break for lunch, if you want to play around with vinegar and ammonia, and you can send this back and forth to the acid side and alkali side back and forth over and over again and you will see the same thing each time.   I have like 10 minutes left, is that right.  So if there are questions.
A	At the last time  we added different oils before we added the lye and water, so can you add like the rest of our stuff in there at any time? 
KD	So the question is can you add the essential oils into the oil before you added the lye when you made soap last time, can you add everything in before you add lye and my answer is the way we make soap is, the lye is always the last thing to go in.  Because we want to get everything mixed in our leisure and make sure it's done well before the clock starts ticking, so the lye is always the last thing that we put in.  Now if you have a reason like a botanical that you are trying to keep suspended or the salt that you don't want it all settling to the bottom, there is a thing that you might add in at the end  There was another notion about what if you are trying to make different colors in the same soap.  Now nothing to stop you from adding your color at the end, but if you wanted to get your color added at the beginning, just make two batches of soap, two batches of oil with its color and two batches of lye and put them in at the same time, mix them up at the same time and then you've got two separate batches of soap on the same clock with the colors already mixed in.  Am I telling you you must do it that way, no, I'm just saying you have permission to try that out and see if it works for you.
What else?
A	What chemical reaction happens when you get ashes like that ash on the top of your soap.  Like what is going on
KD	So the question is what happens what people call soda ash on the top of the soap?  There are several white things that might show up on the top of your soap and it is easy to confuse them.  So if you are getting soda ash on top of your soap, what does it look like?  It's white, but there lots of white things.
A	Powdery
KD	It's white and powdery.  You will be able to distinguish it with a very expensive piece of equipment that I carry with me (sticking out his tongue). You will be able to tell whether that is, in fact, soda ash.  Soda ash is sodium carbonate and you can say I don't know what sodium carbonate tastes like.  Go to the grocery store and buy a box of washing soda, not baking soda.  Washing soda is in the laundry department, go and find the taste.  It is not quite the zing that you get from sodium hydroxide, but it’s definitely got that kind of sharpness to it and you will be able to tell the difference if that's soda ash if it gives you a zing, you know what sodium hydroxide tastes like.  If you get something less than that, that is sodium carbonate.  I haven't gotten to how you prevent it part, but the third possibility is that you taste it and it just tastes like soap, because it is.  Sometimes you just get a layer of soap at the top that it's a different color from the soap underneath.  So remember the fatty acids have different lengths.  Sometimes birds of a feather flock together and you get a whole layer of soap that is all the same length molecule and it turns into a white layer of soap.  So I want you to be able to distinguish the one from the other.  Now that I've said that, how do you prevent soda ash?  Soda ash comes from sodium hydroxide and soap.  Right?  Carbon dioxide in the air, hitting the sodium hydroxide combining it together and it makes sodium carbonate.  If you want to prevent it, what do you need to do?
A	Air
KD	You need to prevent the air from getting to it.  You would use a high tech very expensive industrial piece of equipment called saran wrap or a lid.  Anything that you can do that will prevent fresh air from hitting a still alkaline soap will prevent soda ash.  You will notice where does it appear?   It appears on the top.  Why is it on the top?
A	The air
KD	That's where the air hit it.   What else
A	I wonder if alcohol would stop that?
KD	All you're doing is dissolving it.  In fact, water will do the same thing.
A	Say it again?
KD	The question was what about wiping it down with alcohol.
A	When I do texture, I do a heavy texture top, so I spray them with alcohol before, as soon as I mold it, I spray the tops, because you can't, the way that you want it, I can't lid it and I don't want them to crack, etc.  Afterwards, I just use my steamer, if it's on top.
KD	So the good news is if it's soda ash, it is easy to get off.  A little bit of water, a lit bit of alcohol, anything, it’s very soluble, both in alcohol and water.  So very easy to clean it off.  What isn't so easy to clean off, if it's not soda ash, if it's actually white soap, well then it's soap, you would have to cut it off at that point.   Are we done?
All right, thank you very much and I will see you this afternoon.

 

X

click Forgot Password? below if your password does not work

Forgot Password?

Join Us

Password Reset
Please enter your e-mail address. You will receive a new password via e-mail.