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I am cutting and pasting my notes exactly as they are:
(Unfortunately the chart did not cut and past well, you'll have to cut and past that section yourself to see what it says. Sorry.)

04/02/2016. I have been toying with the idea of testing various hardening agents. I'm finally doing it. The hardening agents I am testing are Heinze brand 5% acidity Apple Cider Vinegar, Sodium Lactate I've been using that I had purchased in 2015 from Soaper's Choice, and Morton brand Cooking, Canning and Pickling salt because it is plain salt with no additives. I have seven small (8 oz oils) test batches to make all batches using 100% olive oil at 33.333% lye concentration. The ONLY changes will be in the weights of agents/water; all figures listed will be rounded according to the normal mathematical methods. The oils and lye will be the constant in each batch. The only additives besides the hardening agents are colorants to identify which soap was made with which agent. The following is a list identifying each agent and its corresponding colorant:

Colorant Agent Used Percent of Usage Agent Weight (gms) Water Weight (gms) Grams NaOH (Constant) Grams Oil (Constant)
None N/A (Control) N/A (Control) N/A (Control) 61.45 30.72 226.80
Ultramarine Violet Sodium Lactate 2% 4.536 61.45 30.72 226.80
Green Oxide Salt 2% 4.536 61.45 30.72 226.80
Red Oxide Vinegar 100% of water replacement 61.45 0.00 30.72 226.80
Ultramarine Pink Vinegar 75% of water replacement 46.0875 15.3625 30.72 226.80
Yellow Oxide Vinegar 50% of water replacement 30.725 30.725 30.72 226.80
Ultramarine Blue Vinegar 25% of water replacement 15.3625 46.0875 30.72 226.80


All colorants used are ultramarines and oxides by "Mighty Fine" in Cleveland, TN. Each was used at 1/4 tsp dispersed into the 8 oz oil and whisked in with the whisk attachment of the stick blender.


It is 8:35 PM. Let the experiment commence. Of course, I have to eat dinner first and set up the "laboratory" before I can do anything. I've only measured the oils and dispersed the colorants. But I've done that much!!


Got started around 9:40 with the first one, the control batch. The batter was pudding after a few good blasts with the stick blender. Not to self: when making tiny batches, go easy on the stick blender:)


For the salt & sodium lactate batches (green & violet) I was not able to get exactly 4.536 gm salt (knew I wouldn't) or sodium lactate because of the scale. I settled for 4 grams. The total amount of the liquid used was 61 grams and the total amount of the lye used was 31 grams.


Special note of interest. Make sure you put the NaOH into the liquid and dissolve it before adding your "lye" solution to your oils. That fascinating "fact" of 25% (blue) vinegar slowing trace ain't so fascinating is it?


For the 50/50 solution (yellow) I rounded off to 62 gm liquid to make it easier to measure 31 gms of each liquid.


It's Midnight 04/03/2016 and I've finally finished the last batch. Man that was tough. I'm exhausted. This science thing is hard. LOL! Other than the one glitch, everything went smoothly. The reason it took so long is because I had to clean the equipment between batches to minimize cross-contamination. I am going to put them in the cold oven to saponify overnight and try to unmold them tomorrow. I think I'll video the unmolding. I don't think the control will be ready to unmold and I believe the 100% vinegar is going to fall out of the mold. It will be interesting to see what happens with the others. Good night!


04/03/2016. I unmolded the soaps today around 4:30 PM. Eveything I thought about what would happen didn't. First of all, the control soap unmolded beautifully and is nice and hard and quite white, which actually surprised me. The olive oil was slightly tinted yellow, so I wasn't expecting the soap to be so white. The salt mold (green) was mushy and broke in half when I unmolded it. The sodium lactate soaps are soft; however, they unmolded quite well. They came out cleanly. The 100% vinegar (red) soap did NOT "fall out of the mold" like I thought it would. It actually stuck badly and I lost half of the Pringle's mold (which I thought it would fall out of, which is why I put it in there in the first place). It was soft and crumbly, similar in consistency to wet chalk. However, it unmolded easily from the silicone mold. It was firm and held its shape. You could apply a considerable amount of pressure to the sides of the bars and not cause any collapse or distortion in shape. But, at the same time, if you touch the top of the bar, it felt soft, tacky and The 75% vinegar (pink), 50% vinegar (yellow) and 25% vinegar (blue) soaps all unmolded easily from the silicone molds.
 
This is an email of the results of the penetrometer testing that Top of Murray Hill did for me on the samples.

"All numbers are kg per square cm. Number of readings and standard deviation is in parentheses. Smaller standard deviation means more consistent readings. In most cases the result is the average of 8 readings, 2 top, 2 bottom, 4 sides. The round samples are 4 top, 4 bottom. For the small control sample, 6 readings were taken.


Control 2.58 (n=6, s=0.09)


Salt 2.49 (n=8, s=0.20)


Sodium lactate 2.96 (n=8, s=0.19)


Sodium acetate:


25% vinegar 3.23 (n=8, s=0.13)
50% vinegar 2.65 (n=8, s=0.16)
75% vinegar 3.13 (n=8, s=0.29)
100% vinegar 3.36 (n=8, s=0.24)


For sodium acetate, the 50% vinegar sample produced unusual results. This could be due to an error in preparing the sample, or perhaps the 25% and 50% samples are reversed."


I was, and still am, grateful to TOMH for all of his help with my vinegar experiments. I do like to use vinegar in my recipes. It does make for a harder bar of soap that is easier to unmold. Unless, of course, you are using a Pringles singles cup as a mold; then you're pretty much scr**d. FYI: I've been using one of these tester soaps (a pink one - 75% vinegar) as tooth soap. It works well and doesn't taste horrible.
 
Done!! I've posted my notes (exactly as they were) from Evernote and an email message from TOMH. I hope this helps.

Excellent. Thank you very much, Teresa. That has helped me very much. i am about to make my first batch of vinegar soap. Fingers crossed.

So I used masterbatched lye and masterbatched neutralised vinegar. I added 16g NaOH to 500g vinegar.
This saved me a lot of calculations (it still took me all day to work out what I wanted to make and how to do it but I am sure there was some savings in there somewhere!!).

I used 31% lye concentration and 2% SF. I mixed mica with 3/4 of the mix and then added confetti and poured it into the mold. By the time I sprinkled a little AC on top it was hard enough to pour the plain top over the base. It took about 5 mins to be able to do a bit of a spoon swirl on the top. I usually have to wait 20 mins to do this when i don't use vinegar. So trace was sped up some.

I am waiting for the oven to cool (testing it with my new laser gun thermometer - thank you Santa) to 100*F and put it in at 3pm and left it overnight. I cut it at 7am with a wire cutter and it was easy to cut but quite solid. Absolutely no mushy bits and no crumbling. Could have been cut earlier if required. Took Teresa's advice and haven't tried it yet! :)

Question: I usually use dissolved salt and CA in my mixes and find that the CA makes a difference to soap scum for me. Will I still need to use CA with vinegar added to the mix?
 
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Hey, if my gallon of vinegar weighs 1000 grams, then I multiply that 1000 x .0337 to get the number of grams (33.7) of NaOH to pour into the jug, is that correct?

33.7 grams of NaOH will neutralize 1000 grams of 5% vinegar? Then I could just use this vinegar in place of my extra water?


Yes!
TopofMurrayHill's original calcs show a factor of .0335 so I am being just a tad "hot" with my lye using .0337. It amounts to .2 grams of lye per kilo of vinegar.
I would NOT just put the lye into the vinegar container since I am not sure of the material used is lye and heat safe. NEVER combine lye with anything in glass!!!
The reaction is exothermic ( releases heat) so I pour vinegar into one of my pitchers that is for soaping ( Dollar Store) and weigh the lye in it's own dry container, combine mix, wait for it to cool down some and funnel it into the jug that lives in the 'fridge.

If you know that you are going to use sodium citrate in your soap you could also react citric acid after mixing into the vinegar while it's still warm as well. I do not since I want more control over the amount of sodium citrate in each batch.
 
"Question: I usually use dissolved salt and CA in my mixes and find that the CA makes a difference to soap scum for me. Will I still need to use CA with vinegar added to the mix?"

Vinegar does not seem to help here with the soap scum so yes.
Mixing the CA in and reacting it is also a heat producer so use caution. I use different lye concentrations in different batches of soap so I do not master batch CA in the vinegar.

Since the SA and CA take up "space" in the water you will not be able to dissolve as much salt in the liquid as you could in plain water. The same is true for sugar. The molecular bonding "space" is being occupied by SA and CA.


I'm learning stuff!
I didn't know that when I got here.
Thanks SMF.
 
"Question: I usually use dissolved salt and CA in my mixes and find that the CA makes a difference to soap scum for me.

Since the SA and CA take up "space" in the water you will not be able to dissolve as much salt in the liquid as you could in plain water. The same is true for sugar. The molecular bonding "space" is being occupied by SA and CA.

With 50/50 master arch lye water and 50% vinegar I still have 3 tsp of water remaining for colour and CA. Thank you.
 
Yes!
TopofMurrayHill's original calcs show a factor of .0335 so I am being just a tad "hot" with my lye using .0337. It amounts to .2 grams of lye per kilo of vinegar.
I would NOT just put the lye into the vinegar container since I am not sure of the material used is lye and heat safe. NEVER combine lye with anything in glass!!!
The reaction is exothermic ( releases heat) so I pour vinegar into one of my pitchers that is for soaping ( Dollar Store) and weigh the lye in it's own dry container, combine mix, wait for it to cool down some and funnel it into the jug that lives in the 'fridge.

If you know that you are going to use sodium citrate in your soap you could also react citric acid after mixing into the vinegar while it's still warm as well. I do not since I want more control over the amount of sodium citrate in each batch.
Thanks, Steve. I finally found TOMH's post regarding the .0335 calculation and was going to as you where you git your .0337 from; this explains it. I'm actually going to do this tonight. I've got an open bottle of vinegar at home. I'll pour all if that into the pitcher that I use when I do the vinegar lye solution and wait until it cools down before pouring back into the vinegar jug. FYI: It's actually safe to use the vinegar jug to make the solution because the jug is a #5 plastic. However, I like doing it in the pitcher because there is a larger surface area and wider mouth for the heat to disperse.
 
Thanks all. This thread has been very useful. I want to make sure I understand what's going on. I am thinking of making a castile soap with 1600 g of olive oil with full water (38% of oil). I have attached a screenshot of the soapcalc recipe.

If I replace half my water with 5% vinegar I would need .0335*304 = 10.184 grams of extra NaOH to neutralize it.


But assume I calculate my recipe at 0% superfat and I decided NOT to add extra NaOH to neutralize the acetic acid. The NaOH needed to saponify this recipe is 216.76 grams so the amount removed in the acetic acid reaction would amount to 10.184/216.76 or about 4.7% of the total NaOH.



Is that 4.7% the same thing as saying the resulting soap would be 4.7% superfatted?

EDIT: Also, how do any of these calculations change if I decide to replace 5% of my NaOH with KOH?

Again, thanks for all your help.

Scooter

Screen Shot 2016-12-30 at 3.00.14 PM.jpg
 
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Question: I usually use dissolved salt and CA in my mixes and find that the CA makes a difference to soap scum for me. Will I still need to use CA with vinegar added to the mix?

As Steve mentioned, you'll still need the citric acid or sodium citrate. That's because it's the citrate ion we are using to grab ("sequester") some of the calcium in the water and stop it from reacting with the soap to form scum. We don't use anything else to do that other than EDTA.
 
Thanks all. This thread has been very useful. I want to make sure I understand what's going on. I am thinking of making a castile soap with 1600 g of olive oil with full water (38% of oil). I have attached a screenshot of the soapcalc recipe.

If I replace half my water with 5% vinegar I would need .0335*304 = 10.184 grams of extra NaOH to neutralize it.


But assume I calculate my recipe at 0% superfat and I decided NOT to add extra NaOH to neutralize the acetic acid. The NaOH needed to saponify this recipe is 216.76 grams so the amount removed in the acetic acid reaction would amount to 10.184/216.76 or about 4.7% of the total NaOH.



Is that 4.7% the same thing as saying the resulting soap would be 4.7% superfatted?

EDIT: Also, how do any of these calculations change if I decide to replace 5% of my NaOH with KOH?

Again, thanks for all your help.

Scooter

Yes, based on my understanding of the math and science involved, having a 0% lye discount/super fat and not adding any extra NaOH to react with the vinegar, you would end up with a super fat in the soap because the NaOH will react with the acetic acid and the fats, leaving unsaponified. That's actually what I did when (1) the soap I was making was just for me and (2) I was experimenting.

However, I'm really confused at what you are trying to do. The purpose of the vinegar/acetic acid is to harden the soap and cause a quicker trace (at least for me, I don' t know why anyone else uses it). By using 100% olive oil and "full" water, IMO, you are defeating the purpose of the vinegar/acetic acid. Pure olive oil soap is notoriously slow to trace and I believe most people use a water discount (soap at a higher lye concentration) to avoid burning out a stick blender. It also helps reduce the water loss during curing time since high OO soaps take so much longer to cure to avoid snot. Also, replacing some of the NaOH with KOH will produce a softer soap. I curious, why do you want to do that with 100% olive oil? I don't think I've read anywhere on here that people make a dual lye soap out of 100% olive oil. Considering the snot factor of NaOH olive oil soap, I would think a softer OO soap would be really snotty.

FYI: Doing the old complicated math, which I've actually gotten used to, your half water amount (304 g vinegar) will be 288.8 water and 15.2 acetic acid. That ends up being slightly higher than the 2% sodium acetate I normally go for in my recipe. I would have had to throw in an additional 9.4 grams of NaOH to get my 2% (280.32 gr vinegar needed to make 2% sodium acetate). Having a real life situation to apply this to, I can see how much easier it is to have the neutralized vinegar on hand to use and not have to worry about "extra" anything.
 
However, I'm really confused at what you are trying to do. The purpose of the vinegar/acetic acid is to harden the soap and cause a quicker trace (at least for me, I don' t know why anyone else uses it). By using 100% olive oil and "full" water, IMO, you are defeating the purpose of the vinegar/acetic acid.
Time to trace really does not matter to me. I got interested in the dual lye trick based on some things I read from Earlene, concerning slime reduction: http://www.soapmakingforum.com/showthread.php?t=62022&highlight=dual+castile

I am not averse to using less water. I am still enough of a newbie to be pretty conservative in how I do things, however.

Scooter

--
 
FYI: Doing the old complicated math, which I've actually gotten used to, your half water amount (304 g vinegar) will be 288.8 water and 15.2 acetic acid. That ends up being slightly higher than the 2% sodium acetate I normally go for in my recipe. I would have had to throw in an additional 9.4 grams of NaOH to get my 2% (280.32 gr vinegar needed to make 2% sodium acetate). Having a real life situation to apply this to, I can see how much easier it is to have the neutralized vinegar on hand to use and not have to worry about "extra" anything.

Thank you for this information, TeresaT...

Back to the castile being soft. I intend to cure it for a year, at least, so I'm assuming it will be plenty hard... again, I am more concerned with lather quality and slime reduction when it comes to the KOH.

Thanks again!

Scooter
 
Thanks all. This thread has been very useful. I want to make sure I understand what's going on. I am thinking of making a castile soap with 1600 g of olive oil with full water (38% of oil). I have attached a screenshot of the soapcalc recipe.

If I replace half my water with 5% vinegar I would need .0335*304 = 10.184 grams of extra NaOH to neutralize it.

But assume I calculate my recipe at 0% superfat and I decided NOT to add extra NaOH to neutralize the acetic acid. The NaOH needed to saponify this recipe is 216.76 grams so the amount removed in the acetic acid reaction would amount to 10.184/216.76 or about 4.7% of the total NaOH.

Is that 4.7% the same thing as saying the resulting soap would be 4.7% superfatted?

EDIT: Also, how do any of these calculations change if I decide to replace 5% of my NaOH with KOH?

Again, thanks for all your help.

Scooter

I've edited the original post to change .0335 to .0333 for people who might search it out later. Why the difference? It's because I calculated some numbers in that example and then used those numbers to calculate the NaOH factor, which introduced a little rounding error. Not a big difference, but it would have been better to calculate the number more directly. I'll show you how it's done.

To make sodium acetate, you need one molecule of sodium hydroxide for each molecule of acetic acid. You need an equal number of both. Since sodium hydroxide molecules weigh less than acetic acid molecules, this is like saying that I need an equal number of tangerines and grapefruits. If I count out the same number into 2 different containers, the grapefruit basket will be heavier.

Our grapefruits are acetic acid molecules, which have a molecular weight of 60. We need an equal number of tangerines, which weigh 40. So you can see that if we had 60 lb of grapefruits, we would be reacting them with 40 lb of tangerines to make our tangrapefruitines. Our NaOH factor comes from calculating those proportions. 40 / 60 = .667 for the weight of tangerines needed for a given weight of grapefruit in order to have an equal number. That would be the number if our vinegar was actually 100% acetic acid in disguise. Since it's only 5%, the complete calculation is 40 / 60 * .05 = .0333.

Potassium hydroxide is a little chunkier, like an orange instead of a tangerine, so for KOH it would be 56 / 60 * .05 = .0467.

Apart from the slight change in the numbers, your conclusions are right. The percentage of NaOH consumed by neutralizing the vinegar is your superfat. That's what it's often called, but lye discount is a better term. We don't know what the residual oil will be in reality, because our caustic can vary in purity and moisture content and the SAP value of our oils varies from lot to lot.

We use a lye discount to avoid possibly using an excess of caustic, and the amount of the discount might give us a ballpark idea of the residual oil. Using the term superfat gets people into the habit of thinking that they are producing exact results. For instance, one might think that using "0% superfat" will produce a perfectly neutralized soap with no residual oil and no excess caustic. Not necessarily so.

When we make bar soap, there is usually a built in safety factor. The NaOH we get is typically very pure and dry, and for practical purposes we generally assume it's strength is 100%, but it's probably a little less. KOH is a very different product, and it's moisture content in particular can vary over a wide range. When you use KOH, you'll have much less idea of the final outcome unless it's been carefully tested and ideally stored.
 
Our NaOH factor comes from calculating those proportions. 40 / 60 = .667 for the weight of tangerines needed for a given weight of grapefruit in order to have an equal number. That would be the number if our vinegar was actually 100% acetic acid in disguise. Since it's only 5%, the complete calculation is 40 / 60 * .05 = .0333.

Potassium hydroxide is a little chunkier, like an orange instead of a tangerine, so for KOH it would be 56 / 60 * .05 = .0467.

This is great information. Thanks so much. I really appreciate how you, and many others here, are so helpful.

Scooter
 
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Thank you for this information, TeresaT...

Back to the castile being soft. I intend to cure it for a year, at least, so I'm assuming it will be plenty hard... again, I am more concerned with lather quality and slime reduction when it comes to the KOH.

Thanks again!

Scooter

I agree that others have said 5% KOH reduces snot in 100% Castile so go for it.
However, Teresa is right in that using full water for Castile is a bit strange. When you cure full water Castile for a year if it is 1 inch thick it will bend as it cures and it takes a long time to trace. There are no colours or additives to 100% Castile so it is just a matter of mix and pour into the mold. There does not seem to be any logic behind using full water.

I would use 30% Lye concentration minimum for castile and even up to 33% lye concentration with vinegar for a first attempt would still be forgiving.
 
I agree that others have said 5% KOH reduces snot in 100% Castile so go for it.
However, Teresa is right in that using full water for Castile is a bit strange. When you cure full water Castile for a year if it is 1 inch thick it will bend as it cures and it takes a long time to trace. There are no colours or additives to 100% Castile so it is just a matter of mix and pour into the mold. There does not seem to be any logic behind using full water.

I would use 30% Lye concentration minimum for castile and even up to 33% lye concentration with vinegar for a first attempt would still be forgiving.

Then onward! I will try that. Thanks to all of you for your patience and advice.

EDIT: I had never heard of soap bending before! Thanks for that info.

Scooter
 
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