[CR 4] Add Poison Damage +Sm, Poison DMG | Any Weapon + Poison
[CR 4] Add Water Damage +Sm, Water DMG | Any Weapon + Essence of Water
[CR 4] Add Fire Damage +Sm, Fire DMG | Any Weapon + Essence of Fire
[CR 5] Add Fire Damage +Lg, Fire DMG | Any Weapon (Except Staff) + Joshua Spice
[CR 4] Add Earth Damage +Sm, Earth DMG | Any Weapon + Essence of Earth
[CR 4] Add Air Damage +Sm, Air DMG | Any Weapon + Essence of Air
Adding essences needs CR 5, adding poison needs only CR 1 ... both add 15% of weapon damage. If you apply multiple elemental enchantments the previous gets replaced. The recipe with Joshua Spice doesn't work.