Can I un-rancid tallow?

[Chickenpoopshoes]

Hoping perhaps someone knows specifically if I can wash tallow to remove the rancidity?
I read on Classic Bells that it can be done and since I found just over a kilo of glass-hard, pure white suet that I rendered a year ago I would love to know if anyone has done it and what the outcome was?!
I had poured it into plastic soup containers with airtight lids and forgotten about it. When I opened the lid there was an instant rancid whiff which then dissipated leaving only a faint tang at the surface.
like I said, this stuff is rock hard- like stone- so I can’t help wondering if only the very top which was exposed to the air inside the tub would have oxidised leaving everything underneath fine?
Is it worth a shot? Will the resulting soap go rancid quicker?

 

[Obsidian]

In my experience, no. I got my hands on some very old bear tallow that had been frozen.

I tried every technique then some to remove the bad scent, nothing helped at all.

 

[Chickenpoopshoes]

Hmmm, I might have to try it anyway... it is just too much to waste!

 

[TheGecko]

From what I have read you can't remove the smell, but you can use it to make soap. In the old days, soap making was the best way to use up old and/or rancid oils instead of tossing them out. You just want to make sure that all the oil is used up by the lye so no superfatting, be careful in your measurements...better for your oil weight to be an ounce under than an ounce over.

Make a small one-pound batch...see what happens.

 

[LilianNoir]

rancidity is the result of oxidation, so no, you can't reverse that process.
Using to make soap might result in DOS if you have superfat. Making a 0% superfat for laundry might work.

Note: this comes purely from my chem knowledge, not from soaping experience b/c I'm still new at that. lol

 

[d20chick]

I read that flour can be used to clean used oil. Maybe it'll work for rancid oil

https://www.ehow.com/how_6404573_make-soap-used-oil.html

 

[GemstonePony]

Intriguing! I would plane the very top and HP the rest, maybe calculating for an additional 15% coconut oil. But I would add the lye water for the whole batch to just the melted tallow, heat and stir with heat under 180°f until it looks like vaseline, and then add the coconut oil (and FO/EO) and heat and stir until it's incorporated. It's sort of like an immediate rebatch. The lye is still gonna eat what it wants when it wants, but this way it's tilted sharply in the direction of eating everything the tallow has available first. And it still might smell, but adding FO/EO after the lye has had a snack means the fragrances won't be as damaged by the lye and may be more effective.

 

[earlene]

Intriguing! I would plane the very top and HP the rest, maybe calculating for an additional 15% coconut oil. But I would add the lye water for the whole batch to just the melted tallow, heat and stir with heat under 180°f until it looks like vaseline, and then add the coconut oil (and FO/EO) and heat and stir until it's incorporated. It's sort of like an immediate rebatch. The lye is still gonna eat what it wants when it wants, but this way it's tilted sharply in the direction of eating everything the tallow has available first. And it still might smell, but adding FO/EO after the lye has had a snack means the fragrances won't be as damaged by the lye and may be more effective.

I think this somehow got attached to the wrong thread. Funny how that happens.

 

[Serena]

Hmmm, I might have to try it anyway... it is just too much to waste!

If it is actually rancid, I don't think re-rendering would take out the smell. But, if you are not sure, it might be worth a try.

I have only had tallow go bad when the people who made it did not use bone-dry jars, or have the lids sealed properly. I also keep my tallow in the freezer or the fridge. I have never had my own tallow go bad.

I have re-rendered fat before. A potato cut in half, in the fat soaks up smells.
I made soap out of bacon drippings one time, and re-rendered the drippings. No bacon smell.
Usually, I re-render fat to get out bits that are not fat.

Low heat rendering helps keep other bad smells from forming. I use low heat and try to render as quickly as I can so that the fat does not smell cooked. (That is my preference. Others might like that smell.)

A pan in the oven is easy.
I like stovetop, but one has to keep watch.

 

[lsg]

The old-timers used potato peelings to help clean fat. You can heat the fat with water and a little baking soda, and let the fat re-solidify, do this several times.