Boil a syrup from water and sugar, then let it cool completely. Drop caraway oil into the vodka and shake thoroughly. Keep in mind that small oil droplets will remain on the surface of the liquid. Add the syrup and let it stand for at least a couple of days. 

The original recipe uses 95% spirit. To achieve a similar strength to liqueur made with strong vodka, add boiled and cooled water to the spirit version. The recipe comes from a household notebook preserved at Võisiku Manor, which reveals that several batches of kummel were made there in 1881–1882. This particular example is dated February 24, 1882, and was calculated for 4 buckets of spirit (EAA 1349.1.727, l 21p).