Here is my recipe of “raw” limoncello (doesn’t need cooking). Unlike the typical recipes, your results will be a very limpid, clear limoncello.
12 non-treated lemons recently picked from the tree; if possible, just having turned yellow (still having some green spots)
one-half liter (2 ½ cups of alcohol), one-half kilo of sugar (2 ½ cups of sugar), and one-half liter (2 ½ cups of water)
Carefully wash the lemons: all the non-yellow impurities should be eliminated. If necessary, use a soft brush, without brushing too hard, so as not to break the protuberances of the rind.
With a sharp knife, cut only the yellow part of the lemon rinds; the white part would confer a truly bitter taste to the liquor. Put the lemon rinds, alcohol, sugar and water in a big, hermetic jar (one that can hold 2 to 3 liters). Stir with a wooden spoon and then close the bottle. Put it aside in the kitchen, where there isn’t too much noise nor too many movements. Stir several times, once in the morning and once in the evening, with a clean wooden spoon. After six days, the limoncello is ready; it only needs to be filtered.
Get a bottle, and put in a funnel, lined with a filter (a big ball of cotton will do). Slowly pour the limoncello (drop by drop) into the funnel; the liquor should be very clear when poured into the bottle. The filtering procedure should last almost a whole day: this should be done when you are certain to be staying home, so as to refilter the liquid every now and then. Don’t touch nor squeeze the ball of cotton: the filtering procedure would’ve been in vain.
The limoncello is to be served at a refrigerated temperature.