Wash all lemons well with a metal sponge to remove all impurities, then dry them.
Using a potato peeler, remove the yellow skin, leaving the white on the lemon.
Put lemon zest onto a cutting board, cut it into thin strips, and then place it in an airtight glass container with alcohol.
Leave to macerate for 3-7 days in a dry, cool place away from light and heat sources (3 days with an alcohol content of about 20 vol.%, 7 days with an alcohol content of about 32 vol.%). The jar will need to be shaken every day to encourage maceration and mix the ingredients well.
After this time, strain the liquid with a kitchen fine mesh strainer and remove the zest. The alcohol was supposed to acquire the classic lemon-yellow color.
Pour water and sugar into a saucepan and bring to a boil. While boiling, stir with a wooden spatula to melt the sugar evenly. When the sugar dissolves, the syrup is ready. Remove the saucepan from the heat and let it cool.
Add the syrup to the strained alcohol and mix well. Pour the liqueur into a bottle or glass container, close it tightly, and let it brew for 30 days. After this time, your homemade Limoncello will be ready to drink.