Is Purifying Tallow Necessary?

Is Purifying Tallow Necessary?

****To clarify, the samples tested in this lab analysis were both from the same cow. We only source our beef fat from one ranch, and the fat comes in boxes. Each box is from one cow. 
There has been questions raised about the validity of this test and that it is not an accurate reflection because it was not third party tested or in a cosmetic lab. Both fat samples were rendered and prepared exactly the same with same temperature exposures. Beef fat is first and foremost a food product, whether the tests were performed by a cosmetic lab or a food and nutrition lab is irrelevant due to the fact they both perform the same types of testing. We will be addressing this in another blog. We are aware this is to take away credibility from the results of this test. ****

Hello fat lovers! Its been a hot minute literally! We are in the 100 degree days here in Arizona.

So todays blog is going to be an important one. The question is to purify or not to purify your tallow? I've been up to my eyeballs for weeks in reading Food Science articles, articles on the cooking methods on Lambs quarters, Red Salmon, and chicken and every meat imaginable. I've spoken to several directors of the Food & Science technology departments at universities. My main question has been does Purifying or the wet render method diminish the benefits of tallow?

My goal with writing this is to share what the results are with purifying/deodorizing the Kidney fat from cows. Does it change the vitamin and nutrient content and or fatty acid profile? Is it becoming less beneficial? There needs to be some clarification on this subject because I haven't found any concrete information. This blog is important to future tallow makers and present ones so they can decide what practices are best for their businesses and customers. If we're all told there is only one right way to do this process of making cosmetic grade tallow, then everyone will follow suit and not question it. 

To give some back story-I have struggled with this idea that tallow needs to be "purified" since I started making tallow. Instead of calling it purifying it should be called deodorizing/refining because that's what the wet method's primary purpose is. To remove some of the smell and refine it making it odorless and white. I've always had lots of questions about the wet rendering method, and it's been difficult to find answers to them. So, to the science articles I went, to the meat and science departments I went, and to the long articles written by Moroccan food and science technology professors I went. It's taken a lot of digging to find answers to the specific questions I have. I hope I can write this cohesively and in a way that's understandable and comprehensive. I will attach some of these articles on the bottom of this blog post.

I have been rendering tallow for around 3 years now, and I have a preferred way that I like to do it. When I started rendering tallow, I read lots of articles, and watched videos so I could learn how to render it specifically for use in skincare. In 2020 there was not nearly as many resources as there are today so it was mostly trial and error before I found a way that worked for me. Most of the information out there has emphasized that tallow needs to be "cleaned" with water and salt before it can be used in skincare or called "cosmetic grade". Some people even say it needs to undergo purifying three times or more. Many of those who say tallow needs purified also claim that purifying doesn't change any of the vitamins, nutrients or remove any of the benefit yet there hasn't been any evidence shown to confirm those claims. 

I've always rendered with those things in mind and done a dry render followed by deodorizing/purifying with water and kosher salt only once. I've chosen to only deodorize once because the fat I use doesn't need it more than that and its very time-consuming work to do all that. Even after the first dry render the fat looks pretty clean. Things that also are concerning is that once water is introduced into the tallow I've found it's difficult to fully remove it all. Even if you freeze it there is still tiny amounts left in the tallow. Even if you let it sit on heat for a long period afterwards there is no way to know if all the water has fully evaporated, and putting the tallow on more heat for longer periods is taking a gamble.

After a wet render I have a technique that I do to remove any remaining water which is let the tallow cool in an upside-down jar then open it and pour out remaining water. And yet I've still seen condensation trapped on the bottom of my jars after I've purified and separated from the water. I usually use it fairly quickly within a couple weeks and during the infusing process I do on low heat I'm fairly confident all the water evaporates out of it.

So, what is the "purifying" process is doing to the fat. How much change is it going through? Does it nutritionally look the same as when it's done with only a dry render? What are the water and salt specifically doing to change the Nutrional and fat profile? Are bacteria liable to grow? Is it significant? Does the ratio of Omega 3s and 6s change? Does the polyunsaturated fat change? Does the stearic or palmitic change? 

I needed to know the answer. I didn't want to be selling compromised tallow to my customers. It seems no other businesses out there have had any clarification on this subject. Have any other businesses taken the steps in testing their tallow to find this information out? Not that I can find or maybe they have but aren't sharing that information. Perhaps many of them are just going off of regurgitated information that someone shared in a YouTube video on purifying? I've spent countless hours scouring the internet in search of articles or blogs from anyone who has a definitive answer to this question. There are none. The only articles I have found are the fatty acid and profile change of meat with different cooking methods. I've never seen anything relating to tallow specifically and what changes occur when cooking with water/salt on heat. This is information we all need to know. Although I was able to find a few articles one is by Sciencedirect from the Encyclopedia of Food and Health from 2016 I will link that here(Fats and Oils Handbook | ScienceDirect). This is a complete book on Fats and Oils that covers extensively the importance of temperature when cooking fats and oils. Here is another article worth reading about the changes in fatty acid composition at different thermal temperatures, (Duckett, S.K. and D.G. Wagner, Effect of Cooking on the Fatty Acid Composition of Beef Intramuscular Lipid. Journal of Food Composition and Analysis, 1998. 11(4): p. 357-362. ( One of the directors of food Science and Technology dept. in Pennsylvania confirmed that purifying it can change the fatty acid profile but said I would have to have it tested to be certain.

With the sheer number of new businesses coming out, and this purification idea that has been pushed, I believe there needs to be some solid information so consumers and businesses can decide how they are going to render their tallow. Rendering is the most important aspect of making tallow and it determines how well the tallow performs and how many nutrients its retaining. It completely impacts the final product, the performance, and benefits of the tallow. Remember the smell is only one aspect. Does removing the "smell" remove the nutrients? I want to know for myself if what I am doing is the wrong way. I want to honor the cow and keep all the benefits of using beef tallow intact. I dont want to wash those away because it has a beefy smell and might turn off customers.

Another important aspect worth mentioning is this search for answers brought me to the very first tallow business that I'm aware of. Vintage Tradition. They started in 2010 before anyone was talking about tallow. They were the pioneers of this movement of using animal fats. I found that they don't wet render at all and advise against it. I will link their page on that here. (Why Vintage Tradition is the Best - Preferred Tallow Balm Skincare). When I messaged and asked why they let me know that wet rendering changes the tallow from its original state. It removes some of the amazing properties that make tallow so beneficial for the skin. Not to mention adding water to tallow increase risk of not only bacteria, mold, yeast and oxidation. Wet rendering makes tallow less shelf stable. Anytime you add water to anything there is a risk for mold and rancidity. 

Buffalo Gal Grassfed Beauty is another business I have been working with that is another one of the first tallow businesses. They have been rendering a very long time. Shalley is the owner and also only does the dry method and has done lots of research on her own. Shalley has also had her buffalo fat tested for a full nutritional panel. She has helped me through this process immensely and we have worked together closely during this process. Shalley is also having tests done on her own as well to find more concrete answers on the effects of purifying. Shalley also made an interesting point to me worth noting. When you take vitamins, herbs or teas or any natural supplement does it not have a smell unique to that supplement? Similarly Tallow is supposed to have a smell. I will be attaching an excellent blog from Shalley. Her blog post was fairly recent and she gives some compelling reason why wet rendering is not a good way to render the fat. (Good Rendering: Why We Don't "Purify" Our Tallow - Buffalo Gal Grassfed Beauty

I decided in May that I would need to have my tallow tested to get any real answers about the purifying. I had two tests done. The first one was a microbial test to see if any bacteria or mold had started growing on the purified tallow. The second test was a fatty acid profile analysis of a purified tallow(purified only once), and a dry rendered tallow. I found a Company called Food Safety Net Services that does food testing for larger companies and smaller ones. They do a complete Nutrional panel, vitamin testing, and any kind of testing you want in regard to food nutrition. The reason I opted for only a fatty acid profile analysis was because every test is extremely expensive. I had to pay for two tests for the comparison of a purified sample and dry rendered sample and it was not cheap. Another main reason I wanted the fatty acid profile analysis was because I wanted to know if the purifying method was causing the omega 3 and 6 ratios to become unbalanced therefore raising the linoleic values also known as Polyunsaturated fats. As time goes on I will get one test done at a time until I have a full panel on every vitamin, nutrient, and mineral present in the tallow I am providing to my customers.

                                           Several Colonies of bacteria growing on this sample.

The results from the microbial tests were not good. I had sent tallow that was purified five days prior to sending it. It was tested several days after that so a total of roughly ten days from purifying to testing. The results showed bacterial growth already. This was tallow that had been separated from water and stored in a mason jar. Not refrigerated. So that showed me that purified tallow was not shelf stable at all. The fact that it couldn't be left on the counter for more than a week and half without bacteria growing in it was surprising.  I was under the impression that purified tallow was still shelf stable like dry rendered tallow. I was wrong. That made me nervous for a lot of reasons. I have been selling purified tallow products for close to three years now. Does that mean they all started growing bacteria shortly after I made them?! I don't know. But the results from this test was unsettling to say the least.

The results from the Fat profile analysis were interesting also.  

Here is the dry rendered samples numbers:

Here are the Purified with water/kosher salt one time sample numbers

If you dont want to go through all the numbers I've noted the main changes in the numbers and acids here:

Myristic Acid- Increase .3g in purified sample
Myristoleic- decreased .20g in purified sample
Palmitic- decreased .3g in the purified sample
Palmitoleic- decreased .3g in the purified
Margeric- decreased .2g in the purified
Stearic- decreased .46g in the purified
cis-oleic- increased in .4g in the purified
Arachidic- decreased .1g in purified
Total fat-decreased .2g in the purified
Monounsaturated fat - increased .56g in the purified
Omega 3- stayed the same
Omega 6- increased .5g in the purified
Omega 9 - stayed the same
Polyunsaturated fat- increased .5g in purified
Saturated fat- decreased .64g in the purified.
Lauric Acid- increased 1g


What do these increases and decreases mean? They mean that the fatty acid profile indeed does change. Tallow when rendered with only the dry method on lower heat and without water preserves the natural balance of the tallow and Omega 3 to 6 ratio. This is why it is recommended to render it low and slow. If it's been done on high heat in a short amount of time, then the nutrients/fatty acid profile and any vitamin content is liable to being damaged/changed. Its important to note that the Omega 6s/polyunsaturated fats increased after purifying. I would imagine if I had sent in a sample that had been purified 3x then those numbers would be considerably higher. Myristoleic decreased by .20g in the purified sample. Myristoleic is biosynthesized from myristic acid and is an important long chain fatty acid. It has many benefits, and sadly it decreased .20g while the Myristic increased by 3g. 

So are these small changes in grams enough to justify sticking with the old methods of dry rendering and not purifying anymore? Thats going to be up to the business owner and consumer. 

Hopefully this helped bring some clarity. I know it's been a real eye opener for me personally considering I have purified this whole time and was under the belief it was required. Perhaps this will change the way people look at tallow. It's an animal fat full of nutrients and it smells like animal fat. There are ways around that without having to purify :). We are no longer purifying our tallow and have quietly stopped for several weeks now. I didn't want to say anything yet though until the two tests were completed and I had a solid answer as to why.

I will more than likely be writing several more blogs on the different tests done over the next several months to cover all the changes that occur when tallow is purified. Feel free to reach out with any questions. 

Signing off,

Jen with Grassland Beauty

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Hi, nice article. Do you simmer or boil the tallow or just maintain it in low heat for it to melt? And for how long would one heat it in a pan?


Ivy, hi there and thank you for your comment. No there was no chance of cross contamination. Everything was kept very sterile, and everything was cleaned before used. I dont know exactly what type off bacteria was growing, the tests dont show what kind. They just show growth of bacteria that was already present on the sample.

Jennifer M Woodson

Hello. Very interesting read and grateful for your time and money put into investigating this. I’m curious and assume it was- but we’re the collection jars sterilized?- any chance of cross contamination? It’s a shame about the bacteria growing on the purified sample. Would you mind sharing what type of bacteria were colonizing?

Ivy Williams

Delia, can you strain the sheep tallow while its still pretty hot? Beef tallow I usually strain while its still pretty hot to make sure its liquid enough to go through the strainer. That might help with the straining issue.


Thank you for writing this blog. As a business owner i am always learning. Sheep tallow is very dense and it is quite difficult to strain out impurities if not wet rendered, I will need to investigate other techniques now. Thank you!


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