Defrost beef suet, if frozen, then chop into 1 to 2 inch pieces. Add fat trimmings to a medium-sized pot, cover, and cook over very low heat until the fat is rendered and the fat pieces shrink and become crispy. The total cook time can take anywhere from 1 to 3 hours depending on how low your heat setting is.
Use a slotted spoon to remove crispy fat pieces and discard. Use a fine mesh strainer to strain the tallow into a measuring cup.
Pour the tallow into mason jars and allow to cool completely before adding the lids. Hand tighten the lids and store at on the counter or in the pantry. Tallow can also be stored in the refrigerator or the freezer.
Notes
I like straining the tallow into a measuring cup so I know how much tallow is rendered and what size jars I need to store the tallow.
You can strain the tallow through cheesecloth, a paper towel, or a coffee filter if you don't have a fine mesh strainer.
When rendering tallow, keep the temperature as low as possible. You want to avoid burning the tallow which will not only affect the taste but also the color.
Store tallow in the fridge or freeze it for even longer storage!
Use tallow to fry french fries and eggs, in place of butter or oil in recipes. It can also be used to season your cast iron skillets!
If you have a local butcher, see if you can get beef suet for free or at a minimal price.