Place the chicken stock in a medium saucepan and bring to a boil.
In a wide, high-sided pot, heat the butter over medium-high heat until it foams and subsides. Add 1/3 of the apple and saute for a few minutes, until it begins to soften. Add the barley and stir for 3 minutes over high heat.
Combine the grappa and wine, and stir into the pan with the barley. Add the chicken stock, a little at a time, stirring constantly, allowing the barley to absorb the liquid to become firm and creamy, like risotto. This will take about 10 minutes.
Yield: 1 1/2 quarts