Peel the etrogim with a potato peeler, making sure to remove only the yellow rind. Discard the pulp.
2. Place the rind in an airtight jar with the vodka and orange extract and let sit for a minimum of three weeks.
3. After three weeks, make a syrup combining the water and sugar: pour both the water and sugar into a saucepan and stir on low heat until the mixture thickens and turns into a syrup.
4. Cool slightly and add the flavored alcohol into the syrup. Mix slightly and pour into airtight bottles (pickling jars can be used).
5. Let the liqueur mature in a cool, dark place for a minimum of two months.