Pure Key Lime Extract

Using a microplane, remove the zest from the limes.
Using a funnel, add the lime zest and 1/4 cup Everclear to a small sealable glass bottle.
Allow the alcohol to extract the flavor from the zest, about an hour is adequate (you will see the liquid turning a beautiful emerald green color).
Strain the liquid from the zest into another bottle.
Add the remaining 2 Tb Everclear to the zest and mix well, then strain the rinse into the previous liquid.
Discard the exhausted zest.
Cut 4 inches from a clean nylon stocking and pack tightly into the bottom of a small funnel to act as a filter.
Pour the extract into the funnel, with the nozzle in a clean sealable bottle (this is the final bottle to be used for storing the extract).
The packed nylon will filter the cloudy particulates from the extract, it will be slow but you need not be present for the extract to filter-you should see about 2 drops per second.
Keep the funnel covered until the extract has passed through it to minimize evaporation.
Seal the bottle and store in a refrigerator or other cool, dark place.