Bring 8 cups (2 L) water to boil; stir in vinegar and 2 tsp (10 mL) of the salt. Add livers; reduce heat to low and simmer until livers are no longer red at centre when cut at thickest part, 8 to 10 minutes. Drain. Transfer to bowl; let cool. Trim livers of any connective tissue. Mash with fork, in batches if necessary.

Meanwhile, melt unsalted butter in saucepan over low heat; add shallots, juniper berries, bay leaves, pepper, cloves and remaining salt. Cook until shallots are soft and spices are infused in butter, about 10 minutes. Remove bay leaves; set aside.

Add butter mixture and brandy to livers; mix well. Pack in 2-cup (500 mL) pot, smoothing top. Decorate with bay leaves. Pour enough melted butter over liver mixture to seal. Cover and refrigerate for at least 3 days or up to 1 week.