Added a link to the napkin math sheet. I'm rusty, so let me know if it looks like I botched any of the numbers. 

I'm wanting to lean into the synergy between the brewer's kit ([i]which can purify water, among other things[/i]) and the herbalism kit ([i]crafting tea, ointments, salves, potions, etc.[/i]), for roleplay flavor if nothing else.