In a large bowl, mix yeast and sugar into warm water until dissolved. Then, add 2 cups of flour, lard, and salt. Mix in the remaining flour slowly–1/2 cup at a time–and stirring well after each addition. Once the dough becomes too difficult to stir, turn it out onto a lightly floured surface and knead until smooth and elastic; this should take around 8 minutes total.
After lightly oiling a large bowl, take the dough and place it inside. Turn the dough around so that it becomes coated with oil as well. Then, put a damp cloth on top of the bowl and let everything rise in a warm spot for an hour or until it doubles in volume.
Line two 9x5-inch loaf pans with parchment paper or lightly grease them with cooking oil spray.
After you deflate the dough, flour a surface and turn the dough out. Cut it in half so that you have two equal pieces to form into loaves shape. Place them both in prepared pans, cover them with a damp cloth, and let rise until the volume has doubled; this will take approximately 40 minutes.
Preheat the oven to 425 degrees F (220 degrees C).
Place the bread in the preheated oven and lower the temperature to 375 degrees Fahrenheit (190 degrees Celsius). After the oven has heated, put the bread inside and let it bake until the loaf is golden brown. You'll know it's ready when you tap on the bottom of the loaf, and it sounds hollow. This should take approximately 30 minutes.