Rinse 2 organic lemons. Place the lemons (or other citrus fruit) in a clean cotton cloth and suspend the lemon filled cloth in a jar over the vodka without letting the cloth and lemons touch the level of the liquid.
Carefully twist the lid over the cloth to secure the cloth and lemons in place.
Set the jar aside in a dark, cool place for 1-3 months.
After 1-3 months, remove the cloth and lemons.
Make a simple sugar syrup and allow it to cool.
Add the sugar syrup little by little, mixing it with the lemon infused vodka and testing it as you go, and stopping when you've achieved the desired level of sweetness.
Immersion Method
Add the vodka to a large empty jar.
Rinse the fruit well, and then remove the zest from the lemons or other citrus fruits. I find that the easiest method is by using a vegetable peeler to peel off large strips of the peel. Check the back side of the peel for the white pith. If you are removing small strips, in some cases there will be little or no white pith left and you can throw those pieces directly into your jar.
Scrape off the white pith to keep the bitterness from going into the homemade limoncello.
I find the easiest way to remove it is to place the peel yellow side down on a cutting board, and then carefully scraping off the white part with a sharp knife. Try not to use too much pressure when using this method, or you'll end up squeezing out a lot of the oils that we want in our liqueur.
Add the lemon zest pieces to the vodka, or other strong alcohol, and seal the jar. Let it rest in a cool, dark place at least overnight, if you're in a big hurry, but it gets better as you leave it to absorb the flavors for longer. I'd suggest leaving it for at least a week to allow it to really absorb the color and flavor. That said, after a couple of days, my batch was already a nice, bright yellow color and had a strong lemon flavor.
Strain the peels from the alcohol as you bottle it by using a fine sieve, cheesecloth or coffee filter in a funnel.
Make a simple sugar syrup and allow it to cool.
Add the sugar syrup little by little, mixing it with the lemon infused vodka and testing it as you go, and stopping when you've achieved the desired level of sweetness.
Simple Sugar Syrup
Measure out the sugar and water in a small saucepan. Simple syrups are usually made with equal weights of sugar and water, but as this isn't the sort of recipe that needs to be super precise, you can also measure out the ingredients with a volume measurement like cups.
Heat the saucepan over medium heat while stirring the sugar and water together. Keep heating and stirring until the water is simmering and the sugar has fully dissolved in the water.
Remove the pan from the heat source and allow it to cool.
For this recipe, I used a white, refined sugar so that the resulting limoncello would be a pretty yellow color in the pictures. That said, the nice thing about making these sorts of recipes yourself is that you can control the ingredients.
For my home batches, I'll be using an organic demerara sugar next time, and may even try sweetening it with either honey or maple syrup next time instead.
The other nice thing about making this recipe yourself, is that you can control how sweet/strong you want the resulting limoncello to be. As you add more of the sugar syrup, you'll end up with a sweeter, less strong liqueur. I only added around half of the sugar syrup to our batch, and we all felt it was sweet enough for us. Some people may want to add more than even the full batch made with 2 cups of sugar. That, of course, is completely up to you. I would recommend, though, adding the syrup little by little and taste testing along the way so that you don't end up making it too sweet.
Combination method
Begin with the suspension method steps 1-5, followed by the immersion method steps 1-5 using the lemon infused vodka obtained from the suspension method rather than fresh vodka.
Video
Notes
You can use a stronger alcohol like everclear to make limoncello. It is said to better and more quickly absorb the oils form the peels. Of course, it will also give you a stronger limoncello which you may or may not like. You can always add a little more water to the final batch if it's already sweet enough, but still a bit too strong.If you're in a hurry, and don't have a lot of time, but want to add more flavor to your batch, you can also add a few drops of a food safe lemon essential oil to your batch. I tried it in a small bottle of mine, and really loved the added flavor/scent that it gave the liqueur.