I used a recipe from the New York Times from 2004/2005 (sorry, couldn't find the link again) and it turned out pretty good. One of the best descriptions I read about when to know if you had soaked the peel long enough was that they become crispy like a potato chip when the limoncello is done. When I made mine, that is exactly what happened.
Also, I made mine with everclear (per the NYT recipe), but thought that was WAY too strong. If I ever made it again, I would use vodka.
Hope that helps.

I did 80 days and used grain alcohol. It was great. I think most of the recipes work just fine. I've had lots of limencello made lots of different ways and it all tastes great!

I have made it using Giada di Laurentis's recipe from the food network. It turned out really well. I believe her recipe uses limes, but I see no reason why you can't swap lemons for the limes. Her's is made with vodka.

We used grain alcohol once (after reading confusing and conflicting advice), and while it was good, we felt like it was really evident we'd used that. I think I'd try it next time with vodka, like rtra said.

I do 6 to 8 weeks with 100 proof vodka (smirnoff makes it). My friend taught me and has a blog post with a good recipe: http://www.eatboutique.com/2009/05/24/organic-limoncello/

We've made it with grapefruits and Everclear (aka 181) using this detailed recipe http://limoncelloquest.com/limoncello-articles/how-to-make-limoncello/ However, this year we bought something just called grain alcohol and it is undrinkable (like downing lighter fluid). So next time I think I will use wither the everclear or a mixture of vodka and grain alcohol.

Use the type of alcohol you like. I hate Everclear (aka gasoline!) so I used high quality vodka. And the recipe I had called for soaking the lemons in vodka for about a day. I think 40 days is overkill!

As a warning, DO NOT LEAVE THE STOVE. I did for juuuust a minute and ended up with sticky yellow goop everywhere. Once you start heating the mixture, don't stop!

Zest of 18 lemons, 1.5 L of Vodka/Grain Alchohol (50/50) for 1 month. You will notice zest removed is near white in color (i.e. oils have been extracted and now infuse alcohol).

Strain out zest, I used coffee filters or flour sack towels.

Then 4.5:3 sugar/water syrup. Mixed with infused alcohol (i.e. approximately 750ml). Shake every couple days for a month.

60 days total. Great product, converted people that say "I don't really like/love limoncello.

Also, I just zest any organic citrus as I use it for juice. I place it in the freezer and that breaks down some of the cell walls. When I have a whole bunch, I make citruscello.

Sarahbelle is right that if you're going to use vodka make sure it's 100 proof. It'll taste fine wiht 80 proof, but the finished lemoncello won't have a high enough alcohol content to keep it from freezing, which is a problem if you're like me and you like to keep your limoncello in the freezer.

We have a local chef, Dolce Debbie, that has a great recipe posted on her website:

http://www.savoryadventures.com/great-recipes/limoncello.html.html

DistrictDarling- no hard liquor should freeze in your freezer. Most home freezers sit around 0 degrees F or warmer and even 40 proof anything won't freeze til about -15F. 80 proof needs close to -34F to freeze. Way colder than any freezer. So freeze your booze with confidence.

I wouldn't go everclear. Thats 100proof and just not meant for real human consumption lol. Most recipes I've seen, and how I was told when we were in Sorrento, Italy is they use a strong (I'd guess 40-80 proof is plenty) vodka, sugar and pack it with peels. They said at least a month, but longer or shorter won't hurt it.

I made it a couple of years ago with 100 proof Smirnoff (I know Absolut also makes 100 proof) and Meyer lemons. So, SO good with the Meyers. I let mine sit for three weeks--LA times method.

http://makingitwithmeleyna.com/166/
http://makingitwithmeleyna.com/make-liquer/

We found huge disparities in recipes too, but after going through and averaging proportions over many recipes to combine into one super recipe, in the end I don't think it matters terribly much - just pick a starting point and give it a go, and adjust it as you find necessary the next time.

We did the following:
For one 750ml bottle of alcohol, zest quite a few (1-3 lb) lemons, taking care not to remove too much white stuff (which I've read makes it bitter), into a clean airtight jar; pour a bottle of alcohol (we used 80-proof Smirnoff which was fine) over it and keep in a dark place for >2 weeks, remembering to shake every so often. When you can't wait any longer, add some simple syrup (we used 1cup sugar/1cup water per 750ml bottle of vodka and that was /plenty/). It can then go back into waiting or straight to the freezer for subsequent drinking. It'll mellow after some waiting, though, which is nice. Have fun!

Most Italians use grain alcohol and we've never had a problem with using it. Make sure you use at least ten lemons per liter. Also, don't heat the lemon-alcohol mixture. Make the simple syrup when you are finished steeping the peel (2 weeks approx) and after it cools, mix w/the strained liquor.

10-16 good lemons (Sunkist) I use a veggie peeler to peel the skin then take a sharp knife and filet any pith off. 1 liter of 190 proof Everclear (Yes, you can find 190 in CA if you have friends in the military). Combine peels and Everclear in non-reactive container able to accommodate approximately 3 quarts. Leave in a cool dark place for at least three weeks moving occasionally. After three or more weeks combine 6 cups of warm water and dissolve two and a half pounds of sugar until clear. Allow to cool and then mix with lemon peel and Everclear. Leave for two weeks. Strain out peel (I use cheesecloth) and bottle. Put bottle in freezer for a few hours. It should come out like syrup when pouring. http://www.sunburstbottle.com/glass-bottles I bought a case of bottles and then gave them out as Christmas presents. I made a lime version that came out great too.

I used Alton Brown's recipe. Soak the lemon for about a week in vodka. Use the *good stuff* not the cheap kind. Keep it in the freezer. It's delicious straight, but I really like to add a shot of it to ginger ale for a nice fizzy boozy lemonade. :)

Does anyone know how long homemade limoncello keeps? I found a bottle I made from 1998 and I'm a little scared of it!

I made some recently for a friend's birthday. One batch was vodka with lemons and the other was everclear with limes. We preferred the limecello because it was less sweet but both are good. The key is serving ice cold. Here is my recipe:http://fieldsofood.wordpress.com/2011/09/18/la-vita-italiana-limoncello-and-limecello/

I would also suggest using organic lemons, since the peel would contain all the pesticides