Update: July 9, 2010: Lately my dad has been soaking the lemon and orange rinds for 1 week, which imparts a more pronounced lemon flavor. The 48 hour soak is still delicious, but it's another option.
1 liter (33.8 oz) pure alcohol – 1 liter = 4.25 cups
8 lemon peels
2 orange peels
2 liters whole milk (67.6 oz) or 8 ¾ cups
5 lbs sugar – 10 cups
1 shot glass whiskey
1 teaspoon pure vanilla extract
1. In a large bowl place lemon and orange peels. Pour pure alcohol over the peels. Soak for 48 hours on the counter top. Note: It's helpful to place a plate on top of the peels so they don't float to the top.
2. Strain lemon and orange alcohol; discard peels. Pour alcohol in a heavy bottomed large saucepan and add milk, sugar, whiskey, and vanilla. Bring to a boil, then reduce until just bubbling, for 5 minutes. Stir continuously, and keep a close eye on it so it does not boil over. Remove from heat and let cool completely. A thin film will form on the top of the limoncello. Using a large spoon, skim it and discard. Then pour limoncello through a fine mesh sieve.
3. Pour into bottles and freeze. Note: We use plastic containers, which are safer to handle than glass. Keep in freezer at all times. Shake before using.
Recipe created by Susan Russo of Food Blogga.