I have to stop, "like this post". Every bite of info on this thread is absolutely great! I have used SL yet, but from reading I will be experimenting soon.
Testing Vinegar/Sodium Acetate In Soap - Phase II
- Thread starter topofmurrayhill
- Start date
Help Support Soapmaking Forum:
Here are some more results.
Sunday night I made 3 kinds of soap: no additive, sodium acetate, sodium lactate. I used grapeseed oil to make a soft soap. To avoid separation and hasten trace, each recipe was 95% grapeseed oil, 4% castor oil and 1% stearic acid, soaped quite hot. I used 300 g oil for each type of soap, split between 3 bars. All were made with a 40% lye.
To simplify the testing, I used anhydrous sodium acetate powder instead of reacting vinegar with sodium hydroxide. In the sodium lactate soap I used 2 tsp 60% sodium lactate solution. In the sodium acetate soap I used 4 tsp of 30% solution.
Before I left for my business trip Monday night, I took 4 penetrometer readings from each soap at the 1 day point. I stopped off on the way home tonight and took 4 more readings of each at the 4 day point. The results are the average of the 4 readings. The numbers are in kg/cm2, with higher readings being harder soap.
1 DAY
No additive - 0.33
Sodium acetate - 0.50
Sodium lactate - 0.63
4 DAYS
No additive - 0.40
Sodium acetate - 1.15
Sodium lactate - 1.00
The additive soaps were slightly harder than the control at the 1 day point, and much harder than the control at 4 days. The hardness of the control didn't increase significantly in this timeframe. The results with the 2 additives were comparable.
Sunday night I made 3 kinds of soap: no additive, sodium acetate, sodium lactate. I used grapeseed oil to make a soft soap. To avoid separation and hasten trace, each recipe was 95% grapeseed oil, 4% castor oil and 1% stearic acid, soaped quite hot. I used 300 g oil for each type of soap, split between 3 bars. All were made with a 40% lye.
To simplify the testing, I used anhydrous sodium acetate powder instead of reacting vinegar with sodium hydroxide. In the sodium lactate soap I used 2 tsp 60% sodium lactate solution. In the sodium acetate soap I used 4 tsp of 30% solution.
Before I left for my business trip Monday night, I took 4 penetrometer readings from each soap at the 1 day point. I stopped off on the way home tonight and took 4 more readings of each at the 4 day point. The results are the average of the 4 readings. The numbers are in kg/cm2, with higher readings being harder soap.
1 DAY
No additive - 0.33
Sodium acetate - 0.50
Sodium lactate - 0.63
4 DAYS
No additive - 0.40
Sodium acetate - 1.15
Sodium lactate - 1.00
The additive soaps were slightly harder than the control at the 1 day point, and much harder than the control at 4 days. The hardness of the control didn't increase significantly in this timeframe. The results with the 2 additives were comparable.
Id like to see how sodium citrate affects this. I find my bars with sodium citrate are much harder than those without. I would think it should have a similar effect.
ngian
Well-Known Member
If that is true I should stop using salt along with sodium citrate.
Where one can get a cheap penetrometer?
kchaystack
Supporting Member
They look really expensive. On Amazon the cheapest in $70
Here I am only focusing on the claimed interchangeability of sodium acetate and lactate as per the Liddle patent, but the general topic of hardening additives would make for some interesting experimentation. Even from here, I can hear the wheels turning in ngian's head.
Here is another angle on it. Soap that is shortened by sodium lactate is more crumbly and brittle than soap with no additive. With no additive it is not only softer but more flexible -- it's less likely to break apart when squashed or bent.
So it would be interesting to compare the texture of the two additives with each other and the control.
The first picture shows the textures of the test soaps when a corner of the bar is crushed. The second shows what happens when the entire bar is bent 90 degrees. Again the additive soaps are very different from the control but very similar to each other.
So it would be interesting to compare the texture of the two additives with each other and the control.
The first picture shows the textures of the test soaps when a corner of the bar is crushed. The second shows what happens when the entire bar is bent 90 degrees. Again the additive soaps are very different from the control but very similar to each other.
That quality you showed above (brittleness) is what I notice in my soaps with SC. I will start a similar experiment next week comparing SC, SL, regular salt, and a control. I'll also do a salt/SC combo and an SC/sugar SL/Sugar and Salt/sugar since people often add them together.
I will also do gel vs ungel. I will not be able to test hardness as you've done here but i will mirror your other tests and add a lather test at 4, 6 and 8 weeks. My soaps will be mini soaps at 1 oz each and will have 4 duplicates. Additives will be added at 1-2%.
I won't add sodium acetate as that is what you are testing here. This is a great thread! I'm very curious how this will turn out.
I will also do gel vs ungel. I will not be able to test hardness as you've done here but i will mirror your other tests and add a lather test at 4, 6 and 8 weeks. My soaps will be mini soaps at 1 oz each and will have 4 duplicates. Additives will be added at 1-2%.
I won't add sodium acetate as that is what you are testing here. This is a great thread! I'm very curious how this will turn out.
That sounds awesome. I'll look forward to it. If you would like to send a set of samples over, I'll be glad to do the penetrometer readings.
I have some objective and some subjective information making me feel that the effect of sodium acetate in this test was a little stronger than the effect of sodium lactate. If I'm right about that, it may be because molar ratios are more comparable than equal weights, so I only needed about 3/4 the usage rate by weight of acetate for similar effect. Something to ponder when thinking about the usage rates in your experiment.
Let me take this opportunity to say that Liddle seems to have been correct as far as he went. On the matter of sodium acetate's equivalence to sodium lactate, my conclusion is that it walks like a duck and quacks like a duck. You can shorten soap with sodium lactate as we commonly discuss, and you can achieve the identical effect by substituting household vinegar in place of water and calculating some extra caustic to react with the acetic acid. Something for TEG and others who have a hard time getting SL.
I'll try it in HP when I get a chance.
ngian
Well-Known Member
That would be a very interesting experiment galaxyMLP. It would be the "hardness lovers" test, after the famous "lather lovers" test ( http://www.modernsoapmaking.com/lather-lovers-additive-testing/ )
One more hardness test for me also includes (in my to do list) the different lye concentration with no hardening additives at all .
I am also looking forward to it.
One more hardness test for me also includes (in my to do list) the different lye concentration with no hardening additives at all .
I am also looking forward to it.
Last edited:
So here is the lather test. Sodium lactate is known to increase the lathering quality of soap. Liddle notes this in the case of both sodium lactate and sodium acetate.
We may come back to the three soaps in the latest experiment to look at this, but I'm going to start by trying the cured soaps from the first testing thread. These are 25% CO, 25% PO, 50% OO. The first has no additive and the one beneath is the sodium acetate soap, which has a richer, creamier lather that is even more apparent in person than in the photo. It seems that maybe the sodium palmitate is more solubilized in the additive soap.
We may come back to the three soaps in the latest experiment to look at this, but I'm going to start by trying the cured soaps from the first testing thread. These are 25% CO, 25% PO, 50% OO. The first has no additive and the one beneath is the sodium acetate soap, which has a richer, creamier lather that is even more apparent in person than in the photo. It seems that maybe the sodium palmitate is more solubilized in the additive soap.
I tossed the test soaps last night because I can't keep every single thing indefinitely. I did some final testing on them first.
I took more penetrometer readings to see how the hardness of the samples had developed in a month. For easy comparison, I'm also including the previous readings that were posted earlier in the thread.
The numbers are in kg/cm2, with higher readings being harder soap.
1 DAY
No additive - 0.33
Sodium acetate - 0.50
Sodium lactate - 0.63
4 DAYS
No additive - 0.40
Sodium acetate - 1.15
Sodium lactate - 1.00
4 WEEKS
No additive - 1.26
Sodium acetate - 2.68
Sodium lactate - 2.45
Sodium acetate maintained it's slight lead from 4 days to 4 weeks. Both additive soaps were about twice as hard as the no-additive soap.
Since SA works so well, I want to point out that you can get 99% acetic acid on eBay for about $10/gal. This might make things simpler and more flexible than using vinegar. You could calculate the additive and the water separately, and use whatever SA usage rate you want.
My final test was lather. The lather test for my first testers is in the preceding post, illustrating the lather enhancing effect of sodium acetate versus no additive. However, with the recipe I used for my recent trio of testers, there was no noticeable difference between the three soaps, at least in this time frame. All had a similar amount of delicate looking bubbly lather that I would describe as 2 on a scale of 1 to 5.
I took more penetrometer readings to see how the hardness of the samples had developed in a month. For easy comparison, I'm also including the previous readings that were posted earlier in the thread.
The numbers are in kg/cm2, with higher readings being harder soap.
1 DAY
No additive - 0.33
Sodium acetate - 0.50
Sodium lactate - 0.63
4 DAYS
No additive - 0.40
Sodium acetate - 1.15
Sodium lactate - 1.00
4 WEEKS
No additive - 1.26
Sodium acetate - 2.68
Sodium lactate - 2.45
Sodium acetate maintained it's slight lead from 4 days to 4 weeks. Both additive soaps were about twice as hard as the no-additive soap.
Since SA works so well, I want to point out that you can get 99% acetic acid on eBay for about $10/gal. This might make things simpler and more flexible than using vinegar. You could calculate the additive and the water separately, and use whatever SA usage rate you want.
My final test was lather. The lather test for my first testers is in the preceding post, illustrating the lather enhancing effect of sodium acetate versus no additive. However, with the recipe I used for my recent trio of testers, there was no noticeable difference between the three soaps, at least in this time frame. All had a similar amount of delicate looking bubbly lather that I would describe as 2 on a scale of 1 to 5.
I have a question. Rather than buying acetic why not just get sodium acetate and use that? ( just 'cause I'm a bit lazy):mrgreen:
Actually there are a few reasons that buying sodium acetate might be the better idea. It's easier and it's also safer because glacial (undiluted) acetic acid can be hazardous. However, there are two forms of sodium acetate, the anhydride and the trihydrate. I would like to understand why their properties differ as they do. For instance, the trihydrate is much less soluble in water.
Anhydrous wants water, tryhdrate has already been chemically bonded if I remember my 1960's chemistry.
I think I'll order some in as long as I can find some anhydrate. The acetic acid has to ship hazmat which means the shipping is more than the material.
The sodium acetate has free shipping.
Using SA also eliminates nearly all of the calculations - and Jan isn't always asking where the vinegar is.
I think I'll order some in as long as I can find some anhydrate. The acetic acid has to ship hazmat which means the shipping is more than the material.
The sodium acetate has free shipping.
Using SA also eliminates nearly all of the calculations - and Jan isn't always asking where the vinegar is.
Anhydrous wants water, tryhdrate has already been chemically bonded if I remember my 1960's chemistry.
I think I'll order some in as long as I can find some anhydrate. The acetic acid has to ship hazmat which means the shipping is more than the material.
The sodium acetate has free shipping.
Using SA also eliminates nearly all of the calculations - and Jan isn't always asking where the vinegar is.
Sounds like a plan. I did the same myself for the second experiment.
So, anhydride sitting around eventually becomes trihydrate. But does it become trihydrate when you dissolve it in water? I guess not, since anhydride is way more soluble.
In 100 g water you can dissolve (depending on who you ask) something like 123 g anhydride or only 46 g trihydrate. So dissolved anhydride remains anhydride or it would precipitate out.
But to make things more confusing, I left a little anhydride solution in a plastic cup for some days and it formed what appeared to be very lovely sodium acetate trihydride crystals.
As you can see, I haven't quite wrapped my mind around it.
Murray, I believe I understand the process to try the vinegar soap recipe. I used grams but I will need to convert to ounces due to my scale. What I am asking about are the circled numbers. What do they represent and how do we get those numbers. I read all the posts on the subject but didn't find the answers there (but I also was on information ovetload).
Thanks
Added: sideways on pic. If needed I will try and straighten. Oops
Thanks
Added: sideways on pic. If needed I will try and straighten. Oops
Last edited:
Heh, call me anything except Murray.
Sorry to take so long. That's a very good question.
The numbers you circled are based on ratios of molecular weights. Some molecules are small and simple and don't weigh much, while others are composed of a lot of atoms and can weigh much more. These are the molecular weights of the 4 molecules involved in this chemical reaction:
acetic acid 60
sodium acetate 82
sodium hydroxide 40
water 18
The chemical reaction is:
1 acetic acid + 1 sodium hydroxide ---> 1 sodium acetate + 1 water
1 molecule acetic acid weighing 60 and 1 molecule sodium hydroxide weighing 40 yield 1 molecule sodium acetate weighing 82 and 1 molecule of water weighing 18. The total weight is the same on both sides because stuff can't just disappear or come out of thin air.
60 + 40 = 100 ---> 82 + 18 = 100
This ratio of weights holds at any level. 60 tons acetic acid reacted with 40 tons NaOH yields 82 tons sodium acetate and 18 tons of water. Or ounces or grams or pounds or milligrams. The units don't matter, just the relative weights.
So what is the relative weight of acetic acid to sodium acetate in this reaction? It's 60/82 = .73. To make 82 grams (or any other amount) of sodium acetate, we multiply it by .73, which is 60 grams acetic acid. To make 10 grams sodium acetate, multiply by .73 and you need 7.3 grams acetic acid.
We will be needing sodium hydroxide too, which is the same thing except 40 per 82, which is 40/82 = .49.
Last edited:
OH MY GOSH! I am stealing this. I've already copied the photo (and I'll turn it right side up), NOW it actually makes sense to me. (OK. MORE sense that before, I'm not 100% there.) I need to take your ciphering and actually write it down myself and think of my recipe and my ACV and my kitchen and then I'll totally understand it. (I'm a really weird learner. I like steps: step 1, turn on computer, step 2....) Anyway, LisaAnne, thank you so much for your post. And TOMH - thank you for your generosity and patience.
I expect apple sauce.
Judging by that piece of paper, I think LisaAnne is using the original, more technical instructions:
http://www.soapmakingforum.com/showpost.php?p=570345&postcount=17
Similar threads
