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Any soap makers on this board making soap from soy or canola oil? My daughter is interested in making soap from farm grown oil. We don't have any olive trees. Most info on the net involves mixing a number of oils to make soap. I am sure we can get something made, but any info would be appreciated.
 
Location: Virginia | Registered: March 17, 2007Reply With QuoteReport This Post
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I made soap from palm kernel flakes. It is similar to making soap from vegetable oil. The reaction is exothermic, it gives off heat. I assume you are thinking of starting small then maybe increasing quantities later, maybe. I did some calculations based on corn oil, since I could get the necessary information for corn oil.
I can explain how I arrived at the amounts I'm giving.
Corn oil has free fatty acids with an average molecular weight of about 279 grams per mole. So the triglyceride has about 878 grams per mole, there are three fatty acids molecules attached to each glycerine molecule.
In 1 litre of corn oil there is about 1.04214123 moles of the triglyceride molecule. So there is 3 times that many moles of free fatty acids molecules, or 3.126423691 moles of ffa.
When 1 litre of corn oil reacts stoiciometrically 100% it takes about 125.0569476 grams of sodium hydroxide (NaOH), or 175.4236333 grams potassium hydroxide (KOH) to make the soap.
95.99162871 grams of glycerine is produced when 1 litre of corn oil makes soap 100%. That's about 76.10531096 millilitres of glycerine.
One litre of corn oil makes about 994.2027337 grams of potassium soap or 944.1799547 grams of sodium soap.
Potassium soap is softer than sodium soap.
The soap making reaction is saponification of triglycerides or neutralization of free fatty acids, Both reactions are exothermic in this case.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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Dissolve the caustic in a little water. Mix the water/caustic solution with the vegetable oil, with stirring. It gets hot when it is warmed a little, due to the exothermic reaction. I did it in a 2 litre heavy wall glass beaker. The soap gets thick, so stirring might be done with a thick glass stirring rod. I put a thermometer in it when I reacted it. I think it got up to about 160-170 degrees centigrade. I was heating it on a sparkless hotplate, but I was only warming it a little. The soap may continue to react for weeks depending on how well it is mixed.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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I know you asked for a method to make soap from soy and/or canola oil. I expect that the average molecular weight of the free fatty acids in corn oil is closely similar compared to soy and canola oil, so that this general proceedure for soap making from corn oil and the quantity of caustic used is probably interchangeable. I read somewhere, that less than the exact amount of caustic is generally used for soap making, so the product will surely not be strongly basic. I read somewhere that the pH of potassium soap is about 10.5. I'm not sure how that is measured, with how much water present.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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I looked up the composition of canola oil as far as per cent of fatty acids relative to each other. Palmitic Acid 4%, Stearic Acid 2%, Oleic Acid 62%, Linoleic Acid 22%, Alpha Linolenic Acid 10%. So the average molecular weight of the free fatty acids present is about 280.6 grams per mole. And the average molecular weight of the triglycerides in canola oil is about 879.8 grams per mole. I found the density of canola oil on the internet as being 0.92 grams per millilitre. To make a story shorter. About 176 grams of KOH 100% should saponify 1 litre of canola oil, or about 125.5 grams NaOH 100% should saponify 1 litre of canola oil. about 96.3 grams of glycerine is produced, being 76.36 millilitres. About 1002.65 grams of potassium soap would be produced per litre of canola oil reacted, and about 949.3 grams of sodium soap (lye soap) would be produced on the 100% saponification of 1 litre of canola oil.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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Thanks for all the info. We will give it a try soon.
 
Location: Virginia | Registered: March 17, 2007Reply With QuoteReport This Post



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The first thing that needs to be determined in soap making is what is called the SAP value. From that you can determine the amounts of caustic and liquid to use to achieve saponification. Most recipes will allow for what is termed super fating, which is intentionally short changing the amount of caustic by about 5% which helps the soap be more creamy in texture.

Canola and soy are short chain oils, with canola winning out. This means that it will be considerably simpler making a type of Castille soap in liquid form than it will bars. Bars can be done although a binding agent will be necessary to "stick" the chains together. This is often done by hydrogenation but can also be done using a secondary acid, like lard with is long chained. Without the binding agent the soap bar will be very soft and squishy; it is still good soap, just not as nice.

Using a secondary acid will necessitate determining the SAP of both acids and combining the results.

Liquid soap is a snap, bars more work.Depends what you want to achieve.

SAP charts:
http://www.fromnaturewithlove.com/resources/sapon.asp
http://www.herbal-howto-guide....SAP-value-chart.html

** It is much simpler to use the glycerine layer for soap making once the methanol has been completely removed.

HTH



** Biodiesel Glycerine Soap - The Guide
- on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


 
Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post
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In chemistry there's a concept called activation energy. In short it amounts to a minimum temperature required to cause the reaction proceed at a significant rate. For example (based on my recollection) I set the hot plate to heat at about the boiling point of methanol, 65 degrees centigrade. That was above the activation energy of saponification (soap making). Since the reaction was exothermic the reaction material in the 2 litre beaker got hotter than 65 degrees centigrade. Industry professionals might know what temperature range the activation temperature is in saponification/soap making, but I don't know what it is. Below activation temperature not much happens. At activation temperature, it becomes apparent that the exothermic reaction is proceeding, it puts out more heat than you apply to it. That's in layman's terms, there are mathematical formulas associated with activation energy that I haven't used in years.

This message has been edited. Last edited by: WesleyB,
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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The two are opposites in that one can cold process soap, meaning exactly that, BUT then the curing period is considerably lengthened while the totality of the caustic is neutralized. This can take up to and at time exceed a month. Battery test by sticking the tip of the bar on the tongue and if it bites like a 9V battery then it is still "hot".

If soap is processed at upper temperatures it is then what is called "hot processed" and then the caustic is immediately neutralized in the process and the soap is ready to go as soon as it cools.

Castille is cold processed while a large percentage of what is done with the glycerine layer is hot processed.



** Biodiesel Glycerine Soap - The Guide
- on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


 
Location: :-) Great White North eh ? | Registered: December 10, 2004Reply With QuoteReport This Post
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Making potassium soap from canola oil. Put 103.5 grams 85% KOH into 150 ml distilled water. Dissolved. Poured the aqueous/KOH solution into a 1 litre beaker. Added 500 millilitres of new store bought canola oil. I've heated and stirred for about 8 hours with a maximum temperature of about 92 degrees centigrade. 3 layers have formed, 1. a lower colorless transparent layer of what is probably glycerine, water and residual KOH, 2. A middle layer that's brownish yellow of what may be soft soap, 3. an upper yellow layer of what may be liquid potassium soap. I'll do some testing later. I stir the reaction material with a large glass stirring rod. A book I read on soap making said to wear gloves while processing soap. I wear protective glasses while stirring the hot reaction material. Hot KOH solution could probably blind a person, so precautions are recomended. Over night I let the beaker cool down, the middle layer solidified into soft soap. I could have poured off the upper layer of what is probably liquid potassium soap. I probably could have used less water to dissolve the KOH in. The saponification reaction appears to be exothermic to me.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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I heated the 1 litre beaker with its contents overnight, about 10-11 hours more. In the morning a thermometer reads 100 degrees centigrade in the reaction material. But now there aren't 3 layer there are 2, a lower glycerine water layer and an upper soft soap layer. I was premature to report three layers as being a final product. The soft soap is light brown colored. So I've heated the reaction materials about 18-19 hours. The reaction might not be complete yet. This is taking longer than I thought hot process, soap making required.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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I calculated on paper that canola oil should require about 125.5 grams per litre of sodium hydroxide to make soap from it. So, I have some lye of unknown purity. It's the old drain cleaner Red Devil lye that used to be sold here. It was inexpensive compared to buying NaOH from a chemical supply. So, dissolved 62.7 grams lye in 150 millilitres distilled water. Put 500 millilitres of new canola oil into a 1 litre beaker, added the sodium hydroxide (lye) aqueous solution into the 1 litre beaker. Heated the beaker with stirring on a sparkless hot plate for about 7 hours so far. I'm stirring about every 5 to twenty minutes. The approximate temperature range I'm heating the reaction mixture at is 60-85 degrees centigrade. The reaction is proceeding. It looks like very light tan/white soap. The beaker's contents is about 670 millilitres. Maybe Legal Eagle can tell me when this soap is done? Does this soap keep reacting a little for days, weeks, or even months? Is there some test that can qualitatively indicate that it is reacted enough? Thanks
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post



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I put some of the potassium soap made from canola oil in tap water. It did not all dissolve. The potassium soap doesn't have a uniform appearance, like the sodium soap I made from canola oil. It is difficult to properly mix the reactants enough to make the reaction work as it should with potassium hydroxide, the way I did it.

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Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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The lye (sodium hydroxide) soap I made from canola oil has set well enough after about 10 days that it is solid enough to use as bar soap. The potassium soap that I made in a similar way is soft soap. I washed my hands with the lye soap and tap water. The lye soap seems to do what it is supposed to when used for washing.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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Interesting. Thanks for posting what you learned. I plan soon to give it a go.
 
Location: Virginia | Registered: March 17, 2007Reply With QuoteReport This Post
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