This mod adds the mortar, pestle, and a new recipe type: "grinding". This makes it easy for you to add your own custom grinding recipes.
It's a bowl made of stone
It's a stick made of stone
Pestle on top,
Mortar on bottom,
Item in the middle
Alters certain vanilla recipes to require the mortar and pestle. You can add your own custom recipes by setting the "type" to "mortarandpestle:grinding". This will preserve the mortar and pestle in the crafting menu.