Brimstone Infusion

You infuse an ordinary flask of alchemist’s fire with
magical brimstone. While so enchanted, the alchemist’s
fire can be thrown 40 feet instead of 20, and it does 2d6
fire damage instead of 1d4. The Dexterity saving throw
to extinguish the flames uses your spell save DC instead
of DC 10. Infused alchemist’s fire returns to its normal
properties after 24 hours.