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Reuse used cooking oil for soap

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Verde

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Hi! I am new here. I am trying to clean used canola cooking oil. I got the oil from a fast food place. The oil is very dark like red wine. There are no bits that I can see. So I tried to put in about 1:2 oil and water. Heated it up and mixed really well. The water separated very nicely. But it's all clear. The oil remained dark. Then I added salt. Same thing. Then I added Dawn. The oil separated in 3 layers. Could someone please tell me what I am doing wrong? Or its just not possible to wash oil? Thanks in advance.
 

DeeAnna

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People wash oil with salty, hot water, and it does help to remove odors and color. If the chemicals that cause the dark color are not water soluble, however, washing with water will not remove these chemicals.

I don't know that I'd use Dawn. The Dawn is emulsifying some of the fat to create that third layer. I can't see how this is going to remove color and odor from the fat that remains.

I can't be of more help to you, I'm afraid.
 

Catscankim

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My grandmom used to use bacon fat for making soap. She always had a can next to the stoves to save it. I dont know she cleaned it (if at all lol). Sorry, thats no help, but i guess using dirty oil is a possibility....
 

KimW

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I don't think you're doing anything wrong. :) Except, as DeeAnna's stated, Dawn is not going to help the situation. Restaurants typically reuse cooking oil until it's no longer useful. Reused cooking oil that's turned very dark is no longer good for cooking, but I don't know about soaping. I'm not clear on the chemical changes that are behind the dark color and substandard cooking qualities. Here's the best article I could find about what has changed in an oil that has turned dark. I'd say try a very small batch to see what happens... And then share what happens with us! :)
 
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Verde

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Thank you everyone for your advise and help. So, I did try to make a small batch. I made coffee spice soap. I mixed the 65% used canola oil, 25% clean coconut and 10% castor oil. I mixed my lye with coffee. Well, I mixed the lye at 85C and the oils at 75C. The mix seized. I added coffee grounds. There were unmixed round bits and whole thing looked half mixed. So, I rebatched it. I added milk with powdered coffee this time instead of brewed. Added cinnamon and ginger powder. The smell of the soap doesnt smell like coffee. So, I added orange, lemon grass and cinnamon oil. I now have a very dark looking soap. Looks like chocolate. Lol! It bubbles well but not sure if it cleans well. 1600478368632592355303707091842.jpg

Forgot to say that the glass in the background contains the oil. I did try to heat up the oil with hot salted water and mixed vigorously but the oil just separated and the water looked very clear.
 

KimW

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How does it smell? Look forward to hearing what it's like in a couple of months! I also wonder what would happen if you soaped it without the coffee.... you have me wanting to get some used oil from our local restaurant. LOL
 

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The soap looks yummy enough to eat! Two things, though:

1. You soaped REALLY hot, which may be why it seized. If this was hot because you were doing hot process, and not cold process, then it could also be that you needed more water. Without knowing your water:lye ratio, I'm only speculating here.

2. Cinnamon oil is only skin-safe in very tiny amounts. It is a known skin irritant that can cause pretty reactions. Before using any EO, you should always check the skin-safe usage rates with a calculator like EOCalc.com, or with a reference book that provides EO safety information.

Let us know how the soap turns out after it cures!
 

Verde

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Yes, you're right! I did put in less water. I think 28% Coz I wasn't sure if there's water that mixed up with the oil. I tried the soap and it's actually quite drying. Could it be because of the cinnamon powder and oil. I just put in maybe 6 drops of cinnamon as its so strong.

How does it smell? Look forward to hearing what it's like in a couple of months! I also wonder what would happen if you soaped it without the coffee.... you have me wanting to get some used oil from our local restaurant. LOL
It smells, not coffee but not fast food either. Kinda strange but not unpleasant. Yes, do try to use your used cooking to make soap. The first batch I made purely with used household cooking oil. It's a mix of duck fat, pork fat, fish oil, vegetable oil which I assumed is coconut oil. The color of my used oil is maybe 60% lighter than the restaurant one but its more smelly because of the fish. The lye seemed to have eaten up the smell. I did put in a few drops of lemon oil and the soap smells soapy before I scented it. It washes kitchen washcloth really well and also don't leave my hand dry. 16004831866208465187798334616298.jpg
 

AliOop

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The first batch I made purely with used household cooking oil. It's a mix of duck fat, pork fat, fish oil, vegetable oil which I assumed is coconut oil.
I also save most of my cooking fats, then "clean" them with the salt water method before soaping with them. It is soap that I just use for family, with a mix of beef, pork, and sometimes a bit of chicken fat (schmalz). I call it my Barnyard Soap. It doesn't smell bad at all and is really nice on the hands.

ETA: all my bacon fat is used for cooking because, well, bacon. Too tasty to use it in soap!
 

Verde

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Hi alioop! I actually just strained my household oil with a paper towel and didn't wash with salted water. But I washed the restaurant oil. It didn't seem to have any effect. When you washed with water, didn't oil retain some water? Also, did the water become dirty? I am just wondering if using recycled oil saleable?

I like barnyard oil! Lol!
 

earlene

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I used to make coffee soap for my husband, using the second-brew method (re-using the grounds to brew a second time) OR using de-caffienated beans because he won't drink those. I am nothing if not frugal when it suits (not always, but in many ways). I also added dried-in-the-oven used coffee grounds for exfoliation. A little goes a long way with the grounds, though, so I learned to be more conservative on those. None of them ever smelled like coffee in finished soap. Coffee just does not lend itself to adding fragrance to soap.

Fragrance oils lend themselves very well to fragrancing soap, so I learned. Finding a coffee fragrance that pleases you or your intended audience, can be a fun journey, but also tricky. Tricky for me, because I hate the sweet milky coffee scents, although my husband does occasionally drink coffee with milk & sugar. Thankfully, not often. So it takes some experimentation to find the FO that suits. There are a lot of them out there.

I haven't made any coffee soap in awhile, because he seemed to get tired of it, plus he got tired of the dripping brownness of the soap in the shower. That could be avoided by just using a coffee FO and no coffee grounds and less colorant, of course.

As for salability of soap made with re-used restaurant cooking oil, some people do do it. There is a soapmaker who sells soap she makes from re-used restaurant oils in a nearby (to me) state. She participates in one of those historic old-towne-type places that have pre-industrial revolution skills demonstrations. I did not like the look or smell of the soap she made. She also did not label it in any way, which per the Fair Packaging and Labeling Act is required for soap. I asked her about her process and I was so not impressed with the knowledge or claims made, that I did not even want to try the soap she made.

So, yes you can sell it, but I am not sure you'd get a lot of buyers.

Also, I've seen & smelled what restaurant fryer oil looks like over the course of it's use and when it goes into the collection bin out back where someone else on the food-chain (pardon my pun) comes along and collects it, after it's been sitting outside in this metal container for possibly a month or so (depending on the size of the town/city & other factors). Well, using oil like that to make soap really just turns me off. I don't think any restaurant workers I know or have known, would really want to wash with soap made from that oil.

Besides being an aesthetic turn-off, the possibility for rancidity is greater, so the soap would be more prone to DOS that soaps made with fresh oil.

Re-using one's own cooking oils is a more controlled process, and for personal family use, certainly seems fine. But the soapmaker has far less control over the cast-off oils from restaurants.
 

Verde

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I used to make coffee soap for my husband, using the second-brew method (re-using the grounds to brew a second time) OR using de-caffienated beans because he won't drink those. I am nothing if not frugal when it suits (not always, but in many ways). I also added dried-in-the-oven used coffee grounds for exfoliation. A little goes a long way with the grounds, though, so I learned to be more conservative on those. None of them ever smelled like coffee in finished soap. Coffee just does not lend itself to adding fragrance to soap.

Fragrance oils lend themselves very well to fragrancing soap, so I learned. Finding a coffee fragrance that pleases you or your intended audience, can be a fun journey, but also tricky. Tricky for me, because I hate the sweet milky coffee scents, although my husband does occasionally drink coffee with milk & sugar. Thankfully, not often. So it takes some experimentation to find the FO that suits. There are a lot of them out there.

I haven't made any coffee soap in awhile, because he seemed to get tired of it, plus he got tired of the dripping brownness of the soap in the shower. That could be avoided by just using a coffee FO and no coffee grounds and less colorant, of course.

As for salability of soap made with re-used restaurant cooking oil, some people do do it. There is a soapmaker who sells soap she makes from re-used restaurant oils in a nearby (to me) state. She participates in one of those historic old-towne-type places that have pre-industrial revolution skills demonstrations. I did not like the look or smell of the soap she made. She also did not label it in any way, which per the Fair Packaging and Labeling Act is required for soap. I asked her about her process and I was so not impressed with the knowledge or claims made, that I did not even want to try the soap she made.

So, yes you can sell it, but I am not sure you'd get a lot of buyers.

Also, I've seen & smelled what restaurant fryer oil looks like over the course of it's use and when it goes into the collection bin out back where someone else on the food-chain (pardon my pun) comes along and collects it, after it's been sitting outside in this metal container for possibly a month or so (depending on the size of the town/city & other factors). Well, using oil like that to make soap really just turns me off. I don't think any restaurant workers I know or have known, would really want to wash with soap made from that oil.

Besides being an aesthetic turn-off, the possibility for rancidity is greater, so the soap would be more prone to DOS that soaps made with fresh oil.

Re-using one's own cooking oils is a more controlled process, and for personal family use, certainly seems fine. But the soapmaker has far less control over the cast-off oils from restaurants.
Yes, you are right. I couldn't smell the coffee grounds at all. Yes, I am not sure if people will be tucked by the used oil. Although, I got these from a restaurant which I know change their oil every Monday. I got them on Tuesday. They're awfully dark though. I will try to make a batch of soap with just the recycled oil and nothing else.
 

d20chick

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I have leftover oil from frying turkey for Thanksgiving (last year). I'm hoping I can still use it for soap. If not, we're frying turkey again this year so I'll have a fresher batch of waste oil to work with. It's a mixture of rice bran oil, soybean oil, and peanut oil.
I made two batches, and had to rebatch the second. The first batch turned out fine. I tried to scent with Rosemary but the smell didn't take, not unpleasant though. For the square bars I added dehydrated orange slices for an exfoliant.
I added a picture of the oil containers and my notes with some of the bars I made. Creamy color, no orange spots, just the actual orange slice.
I wanna try again if the oil is still usable but I wanna clean it first. I've tried boiling the oil and water but with these quantities it seems dangerous, with big oil splashes.
So, how do you boil oil and water??
 

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DeeAnna

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"... I've tried boiling the oil and water but with these quantities it seems dangerous, with big oil splashes. So, how do you boil oil and water?? ..."

The answer is you don't. Never intentionally boil a water and oil mixture, because that's dangerous. Keep the water below boiling -- around 160-180 F -- and stir.
 
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