Graveyard Keeper lets you brew potions. They're used for healing, replenishing Energy, reinforcing the character and can also be used as ingredients of manure. The page contains info that will let you get the alchemy workbench, hand mixer, and the alchemy mill.
How to get alchemy workbench
The alchemy workbench, hand mixer, and alchemy mill blueprints can be obtained from the Witch. She's staying on the Witch's land.
She will give you the items after a conversation - no strings attached.
How to brew potions?
You will need special ingredients for brewing potions. Some of them you can create in the hand mixer and Alchemy Mill. On this equipment, you will be able to convert some of the raw materials into a powder that you will use to create potions.
Then just place the ingredients on the Alchemy workbench, and you will create a potion. You can test different products and brew new potions.
We've prepared a list of potions along with the recipes on another page of this guide.