Used Cooking Oil

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TeeDee

Full Member
Nov 6, 2008
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Used cooking Oil.

I think I grew up with a deep fat fryer somewhere in my mothers kitchen but don't possess one myself.
I've tried an Air Fryer and have come away , frustrated.

Anyhoo I digress. - Made some Falafels last night - had to gently deep fry in a small pan of Oil. Lovely lovely crispy-brown pillows of goodness.

But what to do with the Oil??

So what is the most practical but low impact ( not investing in significant machinery to spin and purify it thank you ) use you can utilise old cooking oil for ? rather than saving it for the tip.
 

Broch

Life Member
Jan 18, 2009
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www.mont-hmg.co.uk
I re-use oil a couple of times depending on how pungent the food ingredients are. I tend to just use a tea strainer, so not too fine really. Obviously, if the food I'm about to fry is 'delicate' tasting, I use fresh oil :)

I confess, I then just dump it, so probably not as environmentally conscientious as I should be!
 

gra_farmer

Full Member
Mar 29, 2016
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Kent
I used to run my old 306 on used cooking oil, filter it using muslin (triple layered at least). Then place in the tank, do 50/50 diesel to oil in the summer, and 30/70 (70% diesel) the rest of the year.

Please note only used cooking oil as fuel on the older diesel engines, not common rail injection.
 
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EdS

Bushcrafter (boy, I've got a lot to say!)
I used to run my old 306 on used cooking oil, filter it using muslin (triple layered at least). Then place in the tank, do 50/50 diesel to oil in the summer, and 30/70 (70% diesel) the rest of the year.

Please note only used cooking oil as fuel on the older diesel engines, not common rail injection.
And Bosche injectors not Lucas or direct injection.
 
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Broch

Life Member
Jan 18, 2009
8,064
7,856
Mid Wales
www.mont-hmg.co.uk
I used to run my old 306 on used cooking oil, filter it using muslin (triple layered at least). Then place in the tank, do 50/50 diesel to oil in the summer, and 30/70 (70% diesel) the rest of the year.

Please note only used cooking oil as fuel on the older diesel engines, not common rail injection.

Is that legal? serious question :)
 

Toddy

Mod
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Jan 21, 2005
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S. Lanarkshire
Cool the pot with oil as quickly as you can. I put mine in a sink of cold water. Then I have a dedicated strainer that fits over a big pickling jar and I strain it into that.
The cooling down quickly really does help keep the oil in better condition.
I use it maybe three or four times, depending on what I've cooked.....spicy Indian type stuff, or Himself's meaty stuff is the last use.
Then it goes into the bin. The council says cold and sealed in a plastic container. I just use the bottle it comes in.

It's weird, because in the days when every chip pan in the land used beef dripping, the blooming things were virtually never cleaned out. I'm sure folks thought it was like a tannin stained teapot, it just enhanced the flavour :dunno:
Then we were all told it was much healthier to use sunflower or vegetable oil instead. Somehow I wonder about that when used oil can smell so bad.

I don't fry much, and my teapots are scoured :)
 

gra_farmer

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Mar 29, 2016
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Is that legal? serious question :)
Grey area, it is all about duty paid differing between food and fuel. Effectively it is recycling and falls under repurposed items where tax has already been paid. But down to interpretation....

I have used oil in the past, and ask police friends whom said it is obvious when you car smells of fish and chips....mine smelt like chicken burgers :)
 
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Tengu

Full Member
Jan 10, 2006
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I think a car that smelt like a chippy would be most attractive.

(Says she who uses a minimal of olive oil...)
 

gra_farmer

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Mar 29, 2016
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Kent
And Bosche injectors not Lucas or direct injection.
It is more down to the washers/seals, when using mets and caustic to break and separate the hydrocarbons, the fuel needs to be washed to stop the dissolving of the rubber seals.

My method was simple, but had to use fuel purchased at the pump.
 

Mesquite

It is what it is.
Mar 5, 2008
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Grey area, it is all about duty paid differing between food and fuel. Effectively it is recycling and falls under repurposed items where tax has already been paid. But down to interpretation....

I have used oil in the past, and ask police friends whom said it is obvious when you car smells of fish and chips....mine smelt like chicken burgers :)
Technically you're supposed to pay the duty on the used veg oil if you use it as a fuel with other taxed fuels.

Excise notice 179 on Bio-fuels explains it a bit more, especially section 3.1.1
 

Keith_Beef

Native
Sep 9, 2003
1,366
268
55
Yvelines, north-west of Paris, France.
I rarely deep-fry anything.

On Saturday I cooked six poppadoms in grapeseed oil that I'd already used twice for that.

I just cool the oil and put it back into the bottle that then goes into a cupboard in the kitchen. The oil still looks clear.

My grandmother and my mother each had a chip pan that was never washed out. But it got used at least once a week, so the oil or grease would have been sterilised.
 
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Toddy

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Jan 21, 2005
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On that note, the dry poppadoms can be quickly rinsed under a tap and popped into the microwave for 30 secs, turned over and given another 30seconds.
Done, cooked, crisp and non greasy :D
 
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gra_farmer

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Mar 29, 2016
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Kent
Technically you're supposed to pay the duty on the used veg oil if you use it as a fuel with other taxed fuels.

Excise notice 179 on Bio-fuels explains it a bit more, especially section 3.1.1
The grey area is 'produce biodiesel' after talking to my police officer friends effectively I was not 'producing biodiesel' I was placing used oil in a fuel tank.

The above is in reference to fractional cracking of oil to a 'biodiesel' which is different.
 

Toddy

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Jan 21, 2005
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Bet they soaked up the oil though :)
A microwave is a good thing. It's not just for 'ding dinner' type cooking.

I admit I only cook what poppadoms folks ask for with their curry/dip. It's quick and easy, and if someone wants another, well it only takes a minute and no need for a oily pan.

Each to their own, but when the central heating is on and the house is pretty much closed down, the last thing I want to do it fry stuff.
 

Keith_Beef

Native
Sep 9, 2003
1,366
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Yvelines, north-west of Paris, France.
A microwave is a good thing. It's not just for 'ding dinner' type cooking.

Yes, they can be very useful. My mum, who's alone now, tends to cook a big batch of fish pie, casserole or similar and freezer it in single portions that she can later reheat.

It would be difficult to find space in our kitchen for one, though, and there is a good extractor hood over the cooker.
 
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Bearmont

Tenderfoot
Dec 21, 2022
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The closer the fat is to fully saturated, the less it will degrade by heating. That's why grandma re-uses her tallow, pours it back into a glass where it turns into a solid. You can't really do this with plant cooking oils, as these are predominantly omega-6. Not only are they competing with healthy omega-3s you would get from greens, walnuts, chia/flax or fish, but they also do react with heat. I would not re-use them often. Filtering works only to clean them superficially, but they do produce trans-fats and react in other ways just by heating; they polymerize (the gummy stuff), and eventually get rancid.

For comparison: Flax oil starts going rancid the moment it meets air and light. That's why you buy it in brown bottles, keep it in the fridge and never heat it.

Tl;dr: It's not terrible to re-use frying oil - for a little while at least, otherwise it'd be a waste. Fast food joints do the same thing. So use it a couple of times in a short timespan, but then toss it. Generally you don't want to re-use oil that's not fully saturated.

Oh! You weren't just asking about food applications. You could clean it and do homemade soap or lamp oil out of it. Could also be used for leather care with items that aren't too precious to use that kind of oil on, like work gloves/boots.
 
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Toddy

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My only quibble with that post is that the fat traditionally used here is Beef Dripping...which is literally the fat that comes off roast beef. The Butchers used to roast beef and slice it thinly for sale. The fat from that was clarified and packed into wax cartons and sold for folks to make chips.
Beef suet, was the fat from around the kidneys, it's a hard crisp fat, very clean, easily peeled and it chops up small, it was used for pastry, suet puddings, clooty dumplings, etc.,
Tallow was all the scraps boiled up and then skimmed and cleaned. It was used for leather, for cordage, etc., and for oiling gate hinges :)
 
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Keith_Beef

Native
Sep 9, 2003
1,366
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Yvelines, north-west of Paris, France.
My only quibble with that post is that the fat traditionally used here is Beef Dripping...which is literally the fat that comes off roast beef. The Butchers used to roast beef and slice it thinly for sale. The fat from that was clarified and packed into wax cartons and sold for folks to make chips.
Beef suet, was the fat from around the kidneys, it's a hard crisp fat, very clean, easily peeled and it chops up small, it was used for pastry, suet puddings, clooty dumplings, etc.,
Tallow was all the scraps boiled up and then skimmed and cleaned. It was used for leather, for cordage, etc., and for oiling gate hinges :)
If you can find a butcher who still gets half sides of beef delivered to then cut into joints in the shop, you can probably get the suet for free. My butcher in the market gets calf's kidneys delivered vacuum packed but with the suet and lets me have it for free.

Tallow is still used as an industrial lubricant for certain applications and a couple of years ago I bought a big tub of it for making leather dressing.
 
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