In an 8 oz jelly jar, add the rhubarb, all the herbs and the vodka. Place a lid and band on the jar, label it with the date and give it a good shake.

Store someplace cool and dark and shake it daily (or whenever you remember to, ha!) for two weeks.

After two weeks, strain the infused vodka into a clean jar using cheesecloth or a paper coffee filter. Place a lid on the jar and set aside.

Place the remaining rhubarb mash in a saucepan with 1/3 cup of water. Place a lid on the pan and bring the mixture to a simmer. As soon as it begins to simmer, turn the heat off and remove the pan from the heat.

Let the vodka-soaked ingredients come to room temperature with the lid on.

Pour the rhubarb mash and liquid into a new jar and put a lid on it.

Let this mixture sit for another week before straining. You may need to strain it twice to remove all sediment.

Add two tablespoons of simple syrup and the strained liquid from the rhubarb mash into the jar with the rhubarb-infused vodka. Stir well to combine. Label and date your finished bitters. You can leave them in the jelly jar or decant them into small dropper bottles.