Rendering fat is the process used to remove meat and particles from the fat of an animal. This must be done in order to store fat for later use. Bits of meat left in fat will cause it to become rancid in storage and unfit for use. Rendering is also a process that can be used to save grease left over after cooking. Leftover cooking grease will go rancid without being rendered or refrigerated because of the bits of food left inside. This cleaning step removes unwanted odors and colors from the fat.
Fat can be rendered from many meats. Fat rendered from pork is called lard. Fat rendered from beef is called tallow. You can use venison, bear meat, chicken, duck or any “hard fat” from animals just as you would beef tallow or lard.
Use a sharp knife to remove the pockets of fat from the meat, collecting the fat into a container. In many animals, the fat is encased inside of a protective membrane. If it is large enough, you can strip the fat from this membrane. Use your knife to further slice the chunks into small bits. Some people prefer to run this through their meat grinder to expose more surface area. This will make rendering go more quickly. If you aren't able to render the fat right away, it can be kept in a freezer. Don't leave it at room temperature if it hasn't been rendered.
WARNING! WARNING! WARNING!
Do not leave the pot unattended at any point in this process. If the pot were to boil over onto your stove, the fat would burst into flames in a grease fire that would be difficult or impossible to contain.
A final step is called clarifying your fat. This will further ensure the purity of your fat and protect it from becoming rancid by removing any remaining bits of meat from the fat. To clarify your fat, place equal amounts of your rendered fat and water into a large pot. Leave lots of space between the contents and the top of the container. Heat the contents to a simmer. Turn of your heat at this point. The residual heat of the pot will cause the fat and water to come to a gentle boil. Allow the pot to sit undisturbed while it cools.
Clarifying liquefies the fat and releases the bits of meat and impurities. When allowed to cool, the impurities settle to the bottom of your pot, the water becomes a middle layer or barrier and the fat rises to the top and solidifies. This top, solid layer is your clarified fat. Scrape any bits that remain off of the bottom of this layer. This can be stored in glass jars or covered containers for later use.
WHAT TO DO WITH THE LEFTOVER BITS
The leftover bits of very crunch meat are called cracklin. Cracklins can be used as flavoring in salads and corn bread. They can also be mixed with peanut butter and beef suet to make a treat for the songbirds in your yard. Dab this mixture between the prongs of a pine cone. Attach a string and hang from a nearby tree where the birds have easy access.
This video shows the how the fat looks during clarifying.
It is a bit long (over 8 minutes). At the 4:45 mark you will see how the contents of the pot appear when they are ready to be removed from the heat.
This video shows how the contents of the pot appear after cooling.
For Further Reading:
Colonial Soap Making. Its History and Techniques
How to Render Duck Fat
How to Render Lard And Why I Do It
EXAMPLE OF KITCHEN RENDERING WITH PICTURES
How I Rendered My Own Lard