For the bitters, coarsely crush all the spices, put them in a jar and pour 200 ml of grain. Close the jar. Leave to infuse for about 14 days, shaking well once a day.
Filter the mixture.
Make 350 g of sugar into syrup with 350 ml of water, then refrigerate. Pour the sugar water into the alcohol and shake well. Add another 100 ml of grain and pour everything together into a boiling hot rinsed bottle. Close the bottle tightly. Let the bitters rest for about 6 weeks before consumption. After the resting period, filter again and fill the bitters into a boiling hot rinsed bottle.