Is Rendering (fat) An Unhealthy Method?

Logan-

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I render beef tallow and use it instead of coconut oil and butter. Do you think the rendering process makes the fat become oxidized and unhealthy?

This is how it looks like during rendering (looks like it's burnt):
how_to_render_Tallow_and_lard_7-600x467.jpg



This is how the end product looks like (white, milky):

how_to_render_Tallow_and_lard_12-600x467.jpg


The images are taken from this web page.
 
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rei

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You will probably get large amounts of oxidized fat that way. My suggestion would be to build a small vacuum chamber and use an induction heater on the outside to heat a pan inside, this way there is no oxidation. A vacuum chamber kit with vacuum pump costs about 200 dollars, 100 if you DIY.

But maybe all this is unnecessary since any cooking produces similar amounts of oxidation.
 
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Logan-

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But, isn't the smoke point of the different fats and oils, and the fats' degree of saturation relevant, in this case?

Lipid peroxidation in culinary oils subjected to thermal stress
PDF (310K) version (full text)

Oxidative stability
Hydrolysis and oxidation are the two primary degradation processes that occur in an oil during cooking.[10] Oxidative stability is how resistant an oil is to reacting with oxygen, breaking down and potentially producing harmful compounds while exposed to continuous heat. Oxidative stability is the best predictor of how an oil behaves during cooking .[11][12][13] The Rancimat® method is one of the most common methods for testing oxidative stability in oils.[13] This determination entails speeding up the oxidation process in the oil (under heat and forced air), which enables its stability to be evaluated by monitoring volatile substances associated with rancidity. It is measured as "induction time" and recorded as total hours before the oil breaks down. Canola oil requires 7.5 hours, for example, whereas extra virgin olive oil (EVOO) and virgin coconut oil will last over a day at 110 °C of continuous heat.[9] The differing stabilities correlate with lower levels of polyunsaturated fatty acids, which are more prone to oxidation. EVOO is high in monounsaturated fatty acids and antioxidants, conferring stability.[9]

The following table presents smoke points and oxidative stability of various fats and oils:

Fat Quality Smoke Point
Almond oil
221°C 430°F[14]
Avocado oil Refined 270°C 520°F[15][16]
Mustard oil
250°C 480°F[17]
Butter
150°C 302°F[18]
Butter Clarified 250°C 482°F[19]
Canola oil
220-230°C[20] 428–446°F
Canola oil (Rapeseed) Expeller press 190-232°C 375-450°F[21]
Canola oil (Rapeseed) Refined 204°C 400°F
Canola oil (Rapeseed) Unrefined 107°C 225°F
Castor oil Refined 200°C[22] 392°F
Coconut oil Refined, dry 232°C 450°F[23]
Coconut oil Unrefined, dry expeller pressed, virgin 177°C 350°F[23]
Corn oil
230-238°C[24] 446-460°F
Corn oil Unrefined 178°C[22] 352°F
Cottonseed oil Refined, bleached, deodorized 220-230°C[25] 428–446 °F
Flaxseed oil Unrefined 107°C 225°F[16]
Lard
190°C 374°F[18]
Olive oil Refined 199-243°C 390-470°F[26]
Olive oil Virgin 210°C[22] 410°F
Olive oil Extra virgin, low acidity, high quality 207°C 405°F[16][9]
Olive oil Extra virgin 190°C 374°F[9]
Olive oil Extra virgin 160°C 320°F[16]
Palm oil Difractionated 235°C[27] 455°F
Peanut oil Refined 232°C[16] 450°F
Peanut oil
227-229°C[16][28] 441-445°F
Peanut oil Unrefined 160°C[16] 320°F
Rice bran oil Refined 232°C[29] 450°F
Safflower oil Unrefined 107°C 225°F[16]
Safflower oil Semirefined 160°C 320°F[16]
Safflower oil Refined 266°C 510°F[16]
Sesame oil Unrefined 177°C 350°F[16]
Sesame oil Semirefined 232°C 450°F[16]
Soybean oil
234°C[30] 453°F
Sunflower oil Neutralized, dewaxed, bleached & deodorized 252-254°C[31] 486–489°F
Sunflower oil Semirefined 232°C[16] 450°F
Sunflower oil
227°C[16] 441°F
Sunflower oil Unrefined, first cold-pressed, raw 107°C[32] 225°F
Sunflower oil, high oleic Refined 232°C 450°F[16]
Sunflower oil, high oleic Unrefined 160°C 320°F[16]
Grape seed oil
216°C 421°F
Vegetable oil blend Refined 220°C[9] 428°F

Smoke point - Wikipedia
 

TeaRex14

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Tallow is fairly safe and resistant fat to oxidation. You're probably okay, grassfed tallow also has elevated levels of CLA and stearic acid which both help to protect against PUFA in the diet. The only problem with tallow (and butter) is that it can cause weight gain much easier then coconut oil. I don't think they have the antimicrobial effects coconut oil has either.
 

Dave Clark

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Can anyone comment on ghee? I can't understand how it is considered such a healthy fat/oil to use when the method of producing it calls for the heating of the butter to separate the milk solids from the fat, which to my mind would mean that the oil would have some degree of oxidation, as well as the cholesterol in the butter that would oxidize when exposed to the simmering/boiling process. Is there something I don't know aboout?
 

TeaRex14

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Can anyone comment on ghee? I can't understand how it is considered such a healthy fat/oil to use when the method of producing it calls for the heating of the butter to separate the milk solids from the fat, which to my mind would mean that the oil would have some degree of oxidation, as well as the cholesterol in the butter that would oxidize when exposed to the simmering/boiling process. Is there something I don't know aboout?
Because ghee is primarily saturated. Saturated fats do not oxidize, at least to the same degree as unsaturated fats. For instance you could reliably use ghee or tallow or coconut oil for frying multiple things. It was not uncommon for people in the old days to use the same grease to cook their food in all day, maybe even all week. You wouldn't want to do this with vegetable oils, besides the fact it's already oxidized before you even cook with it, multiple cookings with it would make your food taste horrible.
 
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a better way is to put the pieces into water and boil. This limits the temperature to 212F. The fat surfaces. Cool and refrigerate and you will have clean good fat.
 
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Logan-

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a better way is to put the pieces into water and boil. This limits the temperature to 212F. The fat surfaces. Cool and refrigerate and you will have clean good fat.

I tried that method, it is called "wet rendering". It is not an efficient method, and it takes lots of time (more than a day) to render the fat, but even for that amount of time it doesn't render efficiently. Half of the hard fat tissue still doesn't yield its fat (liquify), and the end product is always mixed with water, which creates problems (the water explodes) when you are heating the rendered fat to cook with it.
 
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I tried that method, it is called "wet rendering". It is not an efficient method, and it takes lots of time (more than a day) to render the fat, but even for that amount of time it doesn't render efficiently. Half of the hard fat tissue still doesn't yield its fat (liquify), and the end product is always mixed with water, which creates problems (the water explodes) when you are heating the rendered fat to cook with it.

I've used it successfully. I wonder if it would work better in the pressure cooker. It probably would be perfect.

I haven't noticed moisture in the fat....

I just don't want to heat my fat up to 400F. to render it, which I think creates lipid peroxides and contaminants.
 

TeaRex14

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In the past when I would render tallow I would put the beef suet in a oven safe dish chopped into chunks and render it in the oven at about 300 degrees. You can go lower, like 275 and even 250 if you want to, but the process will be a little longer.
 

SQu

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You can also put it in a slow cooker for around 6 hours. I have got good results that way
 

tara

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The only problem with tallow (and butter) is that it can cause weight gain much easier then coconut oil. I don't think they have the antimicrobial effects coconut oil has either.
I think they do have some antimicrobial effects.

Can anyone comment on ghee? I can't understand how it is considered such a healthy fat/oil to use when the method of producing it calls for the heating of the butter to separate the milk solids from the fat, which to my mind would mean that the oil would have some degree of oxidation, as well as the cholesterol in the butter that would oxidize when exposed to the simmering/boiling process. Is there something I don't know about?
Ghee stores better than butter if you don't have a fridge, so in the context of storage in warm climes without refrigeration, it may be 'healthier' than butter? Also, the milk proteins can sometimes be bothersome when frying, or to those with intolerance to the proteins.
 

Ptolemy

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There was a study I read that said ghee is really high in oxidized cholesterol, which is toxic. I'll post the link if I find it.
 
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There was a study I read that said ghee is really high in oxidized cholesterol, which is toxic. I'll post the link if I find it.

You can make clarified butter instead of Ghee. In ghee, the milk solids remain in the fat and get oxidized, but if you make clarified butter then you remove the milk solids and probably prevent a lot of the oxidized protein from being consumed
 

Ptolemy

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You can make clarified butter instead of Ghee. In ghee, the milk solids remain in the fat and get oxidized, but if you make clarified butter then you remove the milk solids and probably prevent a lot of the oxidized protein from being consumed

That's interesting. I'm not really knowledgeable on the differences between ghee and clarified butter. I think clarified butter still contains cholesterol, which might be susceptible to oxidation during heating. Maybe raw butter is best. Here's the study on ghee if anyone's interested:

Cholesterol oxides in Indian ghee: possible cause of unexplained high risk of atherosclerosis in Indian immigrant populations. - PubMed - NCBI

"Two populations of immigrants to London and to the West Indies from the Indian subcontinent have higher than expected morbidity and mortality from atherosclerosis but do not show the commonly accepted major risk factors. This study investigated the hypothesis that ghee, a clarified butter product prized in Indian cooking, contains cholesterol oxides and could therefore be an important source of dietary exposure to cholesterol oxides and an explanation for the high atherosclerosis risk. Substantial amounts of cholesterol oxides were found in ghee (12.3% of sterols), but not in fresh butter, by thin-layer and high-performance-liquid chromatography. Dietary exposure to cholesterol oxides from ghee may offer a logical explanation for the high frequency of atherosclerotic complications in these Indian populations."

This study, however, showed very beneficial effects of ghee:

The effect of ghee (clarified butter) on serum lipid levels and microsomal lipid peroxidation

"For thousands of years Ayurveda has considered ghee to be the healthiest source of edible fat. In the last several decades, ghee has been implicated in the increasing prevalence of CAD in Asian Indians. Our previous research and data available in the literature do not support a conclusion of harmful effects of the moderate consumption of ghee in the general population. Our present study on Fischer inbred rats indicates that consumption of 10% ghee may increase triglyceride levels, but does not increase lipid peroxidation processes that are linked to a higher risk of cardiovascular disease. Many research studies have been published, which report beneficial properties of ghee and herbal mixtures containing ghee. In animal studies, there was a dose-dependent decrease in serum total cholesterol, LDL, VLDL, and triglycerides; decreased liver total cholesterol, triglycerides, and cholesterol esters; and a lower level of nonenzymatic-induced lipid peroxidation in liver homogenate, in Wistar outbred rats. Similar results were obtained with heated (oxidized) ghee. When ghee was used as the sole source of fat at a 10% level, there was a large increase in oleic acid levels and a large decrease in arachidonic acid levels in serum lipids.[24] In rats fed ghee-supplemented diets, there was a significant increase in the biliary excretion of cholesterol with no effect on the HMG CoA reductase activity in liver microsomes.[26] A 10% ghee-supplemented diet decreased arachidonic acid levels in macrophage phospholipids in a dose-dependent manner. Serum thromboxane and prostaglandin levels were significantly decreased and secretion of leukotrienes by activated peritoneal macrophages was significantly decreased.[31]

A study on a rural population in India showed a significantly lower prevalence of coronary heart disease in men who consumed higher amounts of ghee.[40] High doses of medicated ghee decreased serum cholesterol, triglycerides, phospholipids, and cholesterol esters in psoriasis patients. There were significant improvements in the patients’ psoriasis symptoms as well.[27] MAK-4, a herbal mixture containing ghee, increased the resistance of LDL to oxidation in hyperlipidemic patients and had no effect on levels of serum total cholesterol, HDL, LDL, or triglycerides in these patients.[35,36] Other mixtures containing ghee have shown hepatoprotective effects,[41] anticonvulsant activity,[42] effects on enhancement of memory, and enhancement of wound healing.[43]

These positive research findings support the beneficial effects of ghee outlined in the ancient Ayurvedic texts and the therapeutic use of ghee for thousands of years in the Ayurvedic system of medicine.
"
 

fradon

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i render lard the same way. use low heat. the fat is mostly saturated and monunsaturated with like 10percent PUFA. i use this instead of vegetable oils.

if you can get a george foreman grill with a temp control that might be a good way to do it just have the fat drop off
 

Literally

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I second what @ecstatichamster said. I use the water method all the time, after having tried it both ways.

IF it's not efficient, it's precisely in proportion to the degree that you are not overheating the fat. But I think it's more likely that this method took you so long when you tried it because the fat was not cut up into small pieces. This is something you can do yourself with a knife, or just run through a meat grinder (or ask your butcher to do so).

When you use the water method there should be no water left after rendering. You can tell when the water is leaving because the fat will hiss and pop. With some experimentation you can figure out just the right amount to add so that it dehydrates right before it's done -- at which point you need to stir often and watch the heat carefully.

If you do not use the water method it's very easy for the fat on the bottom layer to get to hot.

Seriously overheating the tallow will lead to a yellow color BTW.
 

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