Rendering 101

soap making

All of the products that I make at Fat Chance Farm start out as raw pork lard and beef tallow from sustainably farmed animals. The fat must be rendered to be useable but rendered fat is not just for soapmakers! The resulting lard and tallow can be used for cooking, baking and even frying. And we're not talking Hollandaise Sauce folks, if you can chop an onion and fry an egg, you have the necessary skills and tools to render fat!

Let's start with the fat. I buy fat in rather large quantities, as you might expect. A productive rendering day for me typically involved grinding and cooking off about 50 pounds of tallow and/or lard. If you want to start small, though, you can start with the fat trimmings from any raw piece of meat. It's ok if there are bits of gristle or meat mixed in, the rendering process takes care of that! So you can save up trimmings from steaks, roasts, chops and even chicken. If you're like me and like to leave most of the fat on your meat, get in touch with a local butcher or farmer and ask for leaf lard (from pigs), backfat (also pigs) or suet (usually beef but can also be from goats or sheep). 

lard and tallow

Leaf lard is what I use in soap and what you should plan to get if you plan to use the fat for soap or baking. Once rendered, leaf lard is white and nearly odorless, which makes it perfect for when you don't want your pie crust to be, well, porky.

pastured pigs

Back fat is excellent as a cooking oil. While leaf lard is an internal fat, back fat comes from just under the pig's skin, on its back! This fat is a bit softer and tends to have a bit of a porky or bacony smell and taste after rendering, so works great for roasting potatoes, stir-fries, soups and any number of savory dishes but not so great for pastry (or bars of soap!)

Beef suet is called tallow once rendered and has more limited food applications than pork fats. It has a much higher melting point than lard, making it almost waxy at room temperature. And since it's melting point is higher than human body temperature, it can leave a somewhat greasy feeling in the mouth if used for cooking. However, it shines when used for frying! It has a high smoke point (around 450F) and since it is almost half saturated fat (the rest is monounsaturated with a small percent of polyunsaturated), it is much more stable than its majority polyunsaturated counterparts like canola and vegetable oils. It is also used in more traditional British baking recipes such as boiled puddings, mincemeat pies and certain cakes.

grazing cows

Ok, got your fat? Great! If it's not already cut up, you need to get it into smaller pieces. I use an electric meat grinder (an upgrade from my old hand-cranked model) but you don't need to get it that small. All you need is a sharp knife to chop it into 1-2 inch pieces. The smaller the pieces, the quicker and more completely the fat will render.

grinding fat

 Take you fat pieces and put them in a pan or pot that allows some headroom (that is, don't fill it up all the way!) The fat may foam and rise a bit during the beginning of the process and you don't want it to overflow!

*Safety Note: Do you know how to put out a grease fire? Do NOT use water, the fat will float on the water and spread the fire. Grease fires must be smothered. Fire extinguishers are of course the best option (do you have one in or near your kitchen?) or if the fire is small and somewhat contained you can cover it with a pan lid or pot to starve it of air. Baking soda is also a good option for small grease fires. Shake generously over the flames until smothered. I keep a large box of baking soda on hand (and a fire extinguisher) just in case.

Heat the fat on medium. Soon you will hear some light sizzling and start to see the fat melt. If the fat starts browning, sizzling very noisily or smoking, turn down the heat! A little water in the bottom of the pan will help keep the fat from browning too much and will boil off during the rendering process.

rendering fat

Slow Cooker: If you have a slow cooker, you can use it to render fat on the low setting. This is a pretty easy, fool-proof way to render as it is very unlikely you will burn or overheat the fat. When using a slow cooker, add about half a cup of water in with your fat and start checking up on it after 3-4 hours. You may want to start out with the lid on (so it heats up faster) and once it is bubbling remove the lid to allow moisture to escape more quickly. Then follow the same finishing/pouring directions for stovetop rendering.

Stove Top: Stir occasionally while the fat renders. You will see the fat become more and more liquid as the solids get smaller. You will also see bubbles rising through the liquid fat. This is moisture boiling out of the fat, an important part of the rendering process! Moisture is what allows bacterial growth and spoilage, the reason that rendered fats are so stable and long-lasting, even at room temperature is that all of the moisture has been removed. As the fat continues to bubble steadily, you can begin reducing the temperature to medium-low or low. You want the bubbling to continue but you don't want the fat to overheat.

rendering fat

Remember, once the moisture has been boiled out of the fat it can be very easy to overheat! Unlike water, fat does not "boil" at 212F or show any indication of how hot it is, until it reaches its smoke point (375F for lard, 420F for tallow). That means your pot of fat can quickly get to 300F to 400F without being very obvious about it. Let me tell you, 400F fat is VERY BAD for your skin! So go easy on the heat and remember that electric burners can take a little time to change temperatures, while gas is almost instant.

When is the rendering process complete? First of all the bubbles of moisture will slow or stop and you can also watch for the cracklings, which are the bits of meat and skin that may be in the fat. The cracklings will get brown and crisp during the rendering process and eventually sink to the bottom of the pot once all the fat has been rendered out of them. Pork cracklings are excellent with a little salt and chickens LOVE cracklings of any kind!

You will want to separate your newly rendered fat from the cracklings while still warm but not so hot that you melt (or shatter) the container you're pouring it into (ask me how I know!). For fat destined for soap or baking, I line a colander or strainer with a paper towel, to make sure I catch even the smallest cracklings. For fat that will only be used for cooking, just pouring through a strainer is fine. 

For storage, you can use a mason jar (the type used for canning) or reuse a plastic yogurt container or a stainless steel food storage container. I use food-grade 5-gallon buckets. When pouring into glass or plastic, it's a good idea to check the temperature of the fat with a thermometer and only pour once the fat is below 212F. Only use a glass container if it is glass meant to be used for canning or baking and make sure it is pre-warmed or at least warm room temperature, otherwise, the glass may shatter! Below you can see the results of pouring too hot vs. pouring at the correct temperature:

melted plasticsolid tallow

There you have it! Pure rendered fat, ready for cooking, baking or soapmaking!

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  • Diane at Fat Chance Farm on

    Hi Lorrinda,

    I’m afraid I don’t have much experience striving for the kind of super-purified fat that you are looking for. I do make an effort to remove large meat/gland pieces before rendering but mainly depend on my filter to remove impurities. Folks I know who make very purified fat use the type of filter that is measured in microns to catch every last crackling. So I think you will have more luck focusing on getting a good filter rather than trying to remove every impurity before you render. As for scent, filtering definitely helps reduce any beefy scent but I also find the qualities of the fat itself can contribute to this. Depending on the individual cow’s diet, tallow can range from hard white to an almost soft yellow. The yellowest fat is from cows that are eating fresh spring grass since that grass is very high in carotenoids. Cows eating winter hay typically have the whitest and hardest fat. The breed of cow can also affect fat color and texture. Jerseys, for example, have a better ability to store carotenoids in their fat than other breeds, which results in much yellower fat and milk, no matter the season or diet of the cow (these cows don’t typically hit the beef market though since they are a dairy breed). So there are a lot of variables that can affect the smell and purity of the fat and I think the one that you can best control is the filtering.

    As for texture after cooling, the fat I render cools at all different speeds depending on the season and the texture is usually very consistent. Every once in a while I will get a batch that cools into a grainy texture but I’m honestly not really sure what the variable is. It could be cooling time or it could be a quality of the fat itself that is unrelated. I don’t find that the texture affects soap making at all and when I remelt it to blend with oils for salves and balms, it usually seems to reharden without the grainy texture, though perhaps that is the influence of the other ingredients, it’s hard to say!

    Thanks for your comment!

  • Diane at Fat Chance Farm on

    Hi Ryan, I typically go from freezer to render to use in about a month, so I don’t push its room temperature keep time too much. But if rendered very clean and kept fairly cool (below 70F or even below 60F ideally), I think you could expect at least six months out of it, possibly up to a year depending on conditions. A clean render means filtering out as much of the contaminants as possible and making sure there is no water or moisture leftover after the render. I would be cautious using much if any added water, just because it can be hard to truly get rid of all of it and water will cause spoilage the fastest. Good luck with the rendering!

  • Lorrinda on

    Hello, I make my own fresh skin care for myself and am going to try pasture raised suet/leaf fat to use as a cream. I purchased 4lbs to give it a go. I purchase a 16 once jarred pasture fed tallow but honestly wasn’t convinced that it was all leaf fat or wasn’t rendered multiple times for impurities because it did have a fairly strong fragrance to it so I have chosen render my own. I have chosen to render my leaf fat dry and in the oven baked at 220 degree’s to maintain the nutrients. I do my infused herbal oils between 100-110 degrees for several weeks for the same reason. When I began preparing the fat for the pot it was exactly like your photos above which was really helpful so thanks for those! So, to cut to the quick ,I am striving a really pure refined tallow for my face and the

    maybe the soap I make. But, I especially want the face cream to be the purest for a few reasons so when cutting it up for the pot I was very selective and used only the whitest of the white. Since I have never rendered fat before I thought I would start there. Half of the fat was a beautiful white and I used a lot of that and left a combination of white, and a very light pinkish, as well as a bit that look a very light purple almost like just a faint discoloration. I decided to render that batch tomorrow for tallow soap. I will definitely remove the tiny bit of red that is present before the rendering process but other than that I thought the rest is viable for soap… or even face or body cream I just am not/wasn’t sure if it shouldn’t be rendered? The slight sent that is present in the super white render I am doing is has a very acceptable earthy fragrance that I tested from some cooled oil off the spoon I am stirring it with. I guess do I render EVERYTHING except any meat (red) on it? Also, How should it be cooled in order to avoid the grainy texture? Fast or slow. I am get conflicting information in my searches. Especiallly when blending an oil to it for a softer texture. Tallow is pretty hard! Thank you in advance for any information you can share. Lorrinda
  • Ryan Johnson on

    How long will tallow keep in a food grade bucket? I’m preparing to receive a large quantity of beef fat and have no freezer space. Thank you!

  • Diane at Fat Chance Farm on

    Hi John,

    As long as there’s no visible mold or spoilage the lard should be just fine. Unrendered fat keeps for a pretty long time at refrigerator temperatures and the rendering process pretty thoroughly destroys any spoilage bacteria! Also, for all kinds of meat and fat, being kept at 28-30F makes a world of difference compared to being kept at more typical refrigerator temperatures of 40F. The colder temps add quite a bit of time to its keeping ability. Once rendered you can keep the fat at room temperature provided you will use it within 2-3 weeks. After that the fat can develop stale smells and flavors from rancidity. I typically keep extra cooking fat in the freezer. Fat for soap I keep frozen until rendering, after which I keep it at room temperature but use it up fairly quickly.


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