I.C. Fennel Cordial

Steps

1. 1Install an immersion circulator in a water bath and set it to 140ºF.
2. 2Place the vodka, fennel fronds, sugar, fennel seeds, cardamom seeds, green cardamom pods, and star anise in a one-gallon zip-top freezer bag (see Cook's Note). Remove as much of the air from the bag as possible then seal and submerge the bag in the bath for 1 hour (see Cook's Note).
3. 3Transfer the unopened bag to an ice water bath. Once cool, strain the mixture through a coffee filter set inside a sieve and discard the solids. Don't squeeze or press the solids to extract additional liquid: It will cloud the liqueur and release off flavors.
4. 4Chill before serving.