Step By Step Guide To Making Fuel from Animal Fat

In today’s post we’re going to be talking about biodiesel, specifically making your own biodiesel from animal fats. Making fuel from animal fat has the potential to eliminate our reliance on outside fuel sources for vehicles and machinery. If we are ever in a long-term, grid down scenario, fuel will be a precious commodity. Knowing how to make biodiesel from animal fat could keep your generator and other machines going well after everyone else is thrown back into the dark ages when conventional gasoline runs out.

Step 1 – Can you even use the fuel we’re going to make? 

First and foremost before you start hacking up animal fat and trying to shove it in your gas tank, there’s some things we need to go over first.

First, what we’re creating is biodiesel, and that being said, this fuel will only operate diesel engines. Unfortunately, biodiesel will not run a gasoline-powered vehicle or generator. So if you already have a gas powered generator you’ll have to replace it with a diesel or flex-fuel generator in order to make and use biodiesel. You can mix biodiesel with conventional diesel petrol fuel, but not gasoline.

Step 2 – Animal selection

When making biodiesel from animal fat, the general consensus is that beef tallow is the best fat you can use. However, that’s not “completely” true. The biggest reason that beef tallow is generally thought of as being the best animal fat to use for biodiesel production is simply because there’s a lot more fat on a cow than there is a pig or chicken (both of which you can use to produce fuel).

It’s actually a tradeoff; although you can make more fuel from the fat of one cow, the fuel made from beef tallow will actually solidify at a higher temperature than pig lard will. Chicken or turkey fat will actually stay in a liquid state at lower temperature than both of beef tallow and pork lard. If you want to verify this, put a couple jars on your counter and fill one with liquid beef tallow, liquid pork lard and the last with liquid chicken fat. The beef and pork fat will solidify much faster than the chicken will.


“You’re confusing me….What does this mean?”

Basically it means that if you can get your hands on a lot of chicken fat it’s actually a better performing fuel because you don’t have to be as cautious about it solidifying while it’s being used. However, you’re going to need a heck of a lot of chickens to make the same amount of fuel as you’d get with 1 pig or especially 1 cow.

Either way, any of these fats can be used to make fuel, and yes they can all be rendered at the same time together to make the same fuel… it’s pretty forgiving as long as its rendered and filtered correctly. Just keep in mind that you’ll have to find a way to keep the fuel warm while it’s being used….especially if you’re using beef or pork fat.

Step 2 – Butchering 

If you are butchering your own animals for their fat it’s extremely important that you cut off as little of the actual meat as possible. You don’t want to waste meat; all the solids in the rendering process will be thrown out because any solids that get into your fuel could potentially damage the engine you’re trying to run with it. You can include the bones in the rendering vat, just split the bones down the middle (easier said than done) so that the fat in the bone marrow can melt easier.

Step 3 – Choose your vessel

You’re going to need something to render this fat in. Rendering is simply slowly heating up fat under low heat so that it turns into a liquid but doesn’t burn. The best rendering vat choices would be a steel bathtub or steel tub or trough. However, for smaller batches of fuel you could use a steel bucket.

Anything that won’t burn (remember we’re going to be heating this thing up for a LONG time), is large enough to hold all your solid fat (without stacking it) and has a drainage hole that you can plug will work just fine. You’ll also want to find some sort of pole or stick that you can use for unclogging the drainage hole if it gets clogged and for stirring the fat while it’s rendering.

Step 4 – FIRE!

Rendering fat correctly requires a low, but constant level of heat. You could probably do this in an oven or over a propane burner, but it’s probably best just to do it over an open fire. It doesn’t make a lot of sense to use fuel just to make fuel. Build a fire that’s as big as your rendering vessel and let it burn down to coals.

Your vessel needs to be about 4-6 inches away from the coals. We want to melt the fat, not burn it, so you’ll want to construct something that will hold your vessel above the coals. For a smaller bucket, a simple campfire tripod would work well, however if you’re using a larger vessel you’ll want to find or construct a metal stand that will keep it off the coals. 

Step 5 – Rendering

Rendering a large amount of animal fat will take quite a while. You’ll need to pay close attention to your fire to make sure it doesn’t get too hot when you add more wood. This will burn the fat instead of melting it.

Be sure to stir the fat fairly often. This will help separate the fat from any meat or bones left in the rendering vat and will help keep the rendered fat a stable temperature.

Rendering times can vary greatly. It depends on the type of fat that’s used, the weather, the heat from your fire… there’s a lot of factors. Essentially you just want to melt down as much of the solids as you can.

 Step 6 – Drain the fat

 Try to move any solids left in the rendering vat. Remember, if you butchered the fat correctly there really shouldn’t be a whole lot of solids in there other than the bones. If there are a lot of solids in your vat it’s either meat that should have been taken off during butchering or its fat that hasn’t fully rendered yet. Either way, you’re not going to ruin the fuel if you keep it on the fire for an extra hour or two and it’s better to spend a little more time rendering than it is to waste animal fat.

Put a metal strainer over your fuel container. You’ll need it to catch any of the meat and bone marrow sludge that will build up in your rendered fat. Try to keep the bigger solids like the bones on the far side of the vat while you drain, but don’t take them out yet.

Step 7 – Second verse, same as the first

 Once all the liquid fat has drained, reseal the drainage hole and try to render more fat out of the bones and other solids. This step will make sure you’re getting the most fuel possible out of the rendering process.

Step 8 – Refine!

 Once all the fat has been rendered from the solids, completely clean out and dry the rendering tub. Now we’re going to refine the fat into fuel. The process is the exact same… low and slow. Keep the rendered fat over low heat for several hours, stirring often.

After a few hours, drain the fat (again) into your container but remember to keep your strainer over the container… you’ll be surprised how much sludge you’ll catch the 2nd and even 3rd time you refine the fat. Repeat this entire process one more time. After your fat has been rendered and filtered 3 different times, your fuel is ready to use!

That doesn’t sound too hard right? It’s actually not hard at all. It just takes patience, a few materials and time to make quality biodiesel from animal fat. Once you are finished making your fuel the only thing you need to worry about is making sure your fuel is completely liquefied before you use it. Regardless of what kind of animal fat you use, that fuel will solidify eventually, and if you try and run even slightly solid fuel through an engine you’re going to have serious problems.

You need to make sure your fuel container is receiving some sort of heat while it’s being used in your engine. The easiest way to do this is to keep the container right up close to the engine so that its heat can continue to keep the fuel in a liquid state. Remember though, as soon as that engine stops your fuel is going to start to solidify, you’ll have to fully melt it again before you can use it.

Liberty Generator is one of the best choices in a post SHTF scenario (and not only). The ability to convert any organic material into heat and electric energy can save your life in a SHTF scenario and a lot of money right now. You can learn more about it here.


By Rick, the article fist appread on

2 Replies to “Step By Step Guide To Making Fuel from Animal Fat

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