Limoncello is typically made with lemon rind, alcohol, and simple syrup (one part sugar, one part water). The vodka that I had was only 40% alcohol by volume (not nearly as strong as grain alcohol), but it's all I have, so I decided to make my limoncello without using a simple syrup (i.e. not dilute the already "too weak" alcohol with water from the simple syrup). I've done this before in the past with other infused alcohols, and eventually the sugar dissolves on its own.
So, here's my recipe:
~4 cups cheap vodka
1 heaping cup sugar
5 lemons (organic unless you like to eat chemicals)
1) Wash and dry lemons.
2) Remove the zest from of all the lemons. I used a microplane grater to do this, and grated the on top of a piece of parchment paper, since my wooden cutting board likes to share its garlic flavor with any host (you could use also foil or wax paper). Try to avoid grating any of the pith (white stuff). Alternatively, you can use a sharp vegetable peeler and peel off the rind in chunks.
3) Put zest and sugar in a quart-sized container (I used a mason jar). Cap and shake well.
4) Fill halfway with vodka. Cap and shake again.
5) Top with vodka. Shake some more.
6) Let the mixture sit in a cool, dark place. You can agitate it occasionally to help dissolve the sugar.
7) After 45 days, filter the mixture four times using a coffee filter (or a tea towel or clean t-shirt if you don't have coffee filters lying around). Stick it in your freezer. Enjoy.