Chill the lard slightly in the freezer to make cutting easier, but do not let it freeze completely. Trim away as much meat as possible from the fat, though a small amount of meat is fine. 

Then, cut the fat into small cubes for easier rendering. Place the cubed fat into a medium to large non-reactive, heavy-bottomed pot. 

Cover the pot and slowly render the fat over low heat, making sure there’s no major sizzling. Stir every 30 minutes, or as needed, to prevent sticking or burning.

After about 1.5 hours, the rendering process should begin. If needed, stir more frequently to prevent sticking.

After about 4 hours, most of the lard will be rendered, with a light sizzle. Strain it through a fine-mesh strainer lined with cheesecloth into a heatproof container, leaving enough fat in the pot to cover the pork cubes.

Continue rendering the remaining fat at the same temperature until the leftover pork bits turn brown. This will create your second batch of lard and should take about 30 minutes to 1 hour.

When the second batch is ready, carefully strain it as you did with the first batch, taking precautions with the hot liquid. Press down on the pork cubes while straining to extract as much lard as possible.

Strain and drain the cracklings. Use in other dishes, such as refried beans, sopes, or stews.

Store lard in the refrigerator for daily use. To extend its shelf life, freeze some of it in freezer-friendly containers specifically labeled as such, and avoid using jars with shoulders.