Unfortunately, this requires green walnuts, and by July the Napa walnuts were too mature to be cut. The shells had already formed. I made a mental note of the date for harvesting the green walnuts - June 24.
I picked the walnuts at my friend Cindy's house this afternoon and bought a 1.75 liter bottle of vodka for this batch. The gallon glass jar is one I use for making Meyer lemon "limoncello" - also an Italian favorite.
Because of the size of the jar, I decided to make one and a half recipes of the green walnut liqueur. A recommendation from several of the recipes is to use a heavy cleaver to cut the walnuts. Tap the cleaver into the side of the green walnut (keep fingers well away) and let the weight of the cleaver slice the walnut in half, then quarters.
I mixed the sugar, lemon and spices with the vodka before adding the walnut quarters.
The walnuts are still green and firm and the shells are forming but still papery. They looked just about right.
Ingredients:
3 3/4 Cups sugar
1 1/2 Liter vodka
3 sticks cinnamon
15 whole cloves
1 vanilla bean split lengthwise
zests of two Meyer lemons removed using a vegetable peeler
Mix vodka, sugar, spices, and lemon zest in gallon glass jar. Stir till the sugar is dissolved. Add the walnuts. Close jar and let stand on the counter for two months, shaking the jar every day. (For limoncello I put it in the cabinet and shake it every day for 40 days, add the sugar syrup and shake it every day for another 40 days.)
When it's ready to bottle, filter the liqueur through cheesecloth and pour into clean bottles.
According to David Lebovitz, this liqueur de noix will keep for years in a cool, dry place. It can also be stored in the refrigerator. Supposedly good on vanilla ice cream. We shall see!