Just did some deep fried food yesterday, and ended up with about 300 ml of used grapeseed oil. Normally I end up putting it in the trash, we don't have oil recycling here, at least I don't know of one. So I am thinking about using it to make HP soap for washing dishes. Have anyone done it before? The main question would: does the SAP value change after heating the oil? Any input will be very appreciated.
deep fryer oil for soap making
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Hi, I have made CP soap. With used fry oil. Believe I read, that sap value. Does not change. Can't remember reasons. Something about how it's being used. But it worked well. I just thought of it as any other oil. The shelf life has been reduced. So it would be prone to DOS. I used it at 50% of my recipe. There are several threads on this subject.
artemis
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If I recall, grape seed oil is more prone to DOS to begin with.
I am planning to make HP liquid oil and use it for washing dishes. It will be used quickly, so I don't really worry about DOC, bacterial growth, or how it will smell. My concern is more about PH of the final product and how well it will clean.
I will search threads, thanks for pointing it out, Ford.
I will search threads, thanks for pointing it out, Ford.
Grapeseed oil is a saponifiable fat; ergo you can make soap with it.
The pH will always be alkaline (high pH), because that is the normal chemical nature of soap. Know the purity of your KOH, use a soap recipe calculator to determine the amount of KOH to use based on that purity, measure the fat and KOH accurately, and the soap should be fine.
The sap value doesn't change just because a fat has been heated.
Grapeseed oil soap won't be a strong cleanser for dishes, but it will clean. I'd use it on a sponge for "spot washing" dishes rather than squirt it into a sink full of water -- it won't function as a cleanser if diluted in a lot of tap water.
The pH will always be alkaline (high pH), because that is the normal chemical nature of soap. Know the purity of your KOH, use a soap recipe calculator to determine the amount of KOH to use based on that purity, measure the fat and KOH accurately, and the soap should be fine.
The sap value doesn't change just because a fat has been heated.
Grapeseed oil soap won't be a strong cleanser for dishes, but it will clean. I'd use it on a sponge for "spot washing" dishes rather than squirt it into a sink full of water -- it won't function as a cleanser if diluted in a lot of tap water.
Thanks, DeeAnna.
I was hoping you will chime in. I made some soap by now and know how to calculate KOH and what to add to make it cleansing enough for dishes. My concern was whether prolonged heating will change the chemical structure of the oil and effect the saponification value.
It will not be a single oil soap. I will make it with tallow, 30-35% of coconut oil and then add used oil from my deep fryer.
We will see if the fried spring roll smell persists in the finished soap. But as long as it cleans and doesn't peel skin off my hands - I will be a happy camper.
Will report on it later.
