Kim, Thank you for your help!2 gallons! Oh boooooo - that stinks (no pun intended). Perhaps I am indeed using the wrong term here!
I am speaking of cleaning the oil with water and salt. For liquid oil I usually add 1:3 hard oils so that the cleaned oil can be skimmed off, as described in this post:
Hi. Made a small batch used fry oil soap. From a friends diner. Looks ok. Have not tried it yet. With my original pink mold. Used " canola oil" in the lye calculator. CO and OO and castor. To fill in rest of recipe. 1.7/1 lye concentration. 3% SF. Also added 4ozs. Almond milk. Thanks for looking.www.soapmakingforum.com
I suspect many a folk would discard even that large amount of rancid oil, but I would definitely clean it!
Ah - thank you, DeeAnna!Washing rancid fat is a little like rendering if you use a wet rendering method, but I think it's best to just call it "washing" rather than rendering.
Kim, Thank you for your help!
I did not understand how to clean my walnut oil.
I take water 1 part and salt 2 parts? Right? And boil it together?
Thank you very much, I will clean my walnut oil tomorrow!What you don't want to do (based on personal experience) is mix the water and oil with a stick blender. A SB does too good a job of mixing -- the oil and water may form a semi-permanent emulsion that does not separate easily.
Oh, I am so glad I saw this before I threw out more of my old oils! Can this be done with old kinds of butter as well! I have lots of #'s of butters that I just unpacked that I have been trying to figure out how to get rid of without tossing them in the garbage. None of the oils have been opened and none of them are discolored, so now have to do the smell test. Sounds like a pain in the fanny to do, but some of the oils are expensive and well worth the extra work and 99% of them are gallon size!Washing rancid fat is a little like rendering if you use a wet rendering method, but I think it's best to just call it "washing" rather than rendering.
Rancid fat can be washed with hot, salty water to remove the smelly ketones and aldehydes. Based on my tests, I cannot promise this washing will remove absolutely every hint of rancid odor, but it is worth a try if you are interested. Here are two methods --
Method 1. "...Wash your oil with a brine made of 1 part salt to 10 parts of 180-degree water. You should have equal parts of water to oil. Stir vigorously until it looks cloudy, then allow it to separate. Pour off the oil with a gravy separator and throw away the brine....." source: Heide Braley. How to use rancid oil for soap. HomeSteady. Version dated 21 July 2017. How to Use Rancid Oil for Soap | Homesteady
Method 2. Make a 10% brine solution (1 part salt to 9 parts water). Mix one part of this brine to about three parts oil. Heat to to 160F / 70C. Stir the mixture at 60 revolutions per minute for 1 hour, let the mixture sit quietly for 6 hours, and then separate the brine from the fat. Source: A. Y. Girgis. Production of high quality castile soap from high rancid olive oil. Grasas y Aceites, 54:3 (2003), pg 226-233.
This washing step can be repeated several times if needed. If the odor is still objectionable after two or three washings, the fat is probably not salvageable.