Remove skin (from back fat) or outer membrane (on leaf fat), unless the butcher did this for you. I find this step and the next one are easiest to do when the fat is mostly frozen, but slightly thawed. With back fat, I will make a few cuts, dividing the strip into 2-3″ long chunks, then remove each chunk from the skin. This is more manageable than trying to remove the full piece of skin in one slice.
Cut any larger pieces of fat into smaller chunks, maybe 2 or 3 inches long.
Fill a large stock pot with your chunks of fat. (My stock pot is a 12 quarts.)
Turn the burner on medium to medium low. (I had read that rendering needs to happen at the lowest temperature possible, so my first attempt at rendering lard i kept the burner on its lowest setting. Two hours later I had about 1 inch of liquid fat in the bottom of my pan. It should never take that long, my friends, and there’s no need for it to. Instead, I find it best to monitor the temperature of the liquid lard and keep it at a nice steady temperature of 220 the entire time.)
Monitor your pot by setting an alarm for every 30-40 minutes and checking it each time the alarm goes off. Stir the chunks of fat and check to see that the temperature of the liquid fat is in the 220 range every time the timer goes off.
When you have mainly liquid, with large and small chunks floating on top, use a large slotted spoon to scoop out the pieces of fat.
Carefully pour the liquid lard from your stock pot into a strainer, draped with a thin towel, resting on large bowl.
Carefully adjust your towel, so fresh fabric is covering the strainer, and move your strainer to another large bowl.
Pour strained liquid fat from the first bowl into the second, straining it a second time (after placing chunks in pan of rejects). The more effectively you strain your lard the better tasting (aka not “porky” tasting) it will be.
Pour the strained lard into clean, sanitized jars or molds. I use these molds and find there’s no need to grease them.
IF USING MOLDS: Freeze lard in molds for about 1 hr 15 minutes then pop out and store in freezer-safe container in freezer for years, taking out as needed to replace a stick of butter in baking.
IF USING MASON JARS: wipe rim of jar after filling with liquid lard and place canning lid on with rim, fingertip tight. Within a few hours, the liquid golden fat will turn spreadable-solid and white. The lid should be sealed and you can store your jars of lard in a cool, dark place for years.