Remove stems and seeds from jalapenos.

Puree jalapenos in a food processor with 1 cup cider vinegar.

Combine jalapeno puree, remaining 1 cup cider vinegar, and sugar in a large saucepot.

Bring the mixture to a boil, stirring constantly.

Boil for 10 minutes, stirring constantly.

Stir in liquid pectin.

Return to a rolling boil and boil hard for 1 minute, stirring constantly.

Remove from heat.

Skim off any foam, if necessary.

Stir in a few drops of food coloring, if desired.

Ladle hot jelly into hot jars, leaving 1/4 inch headspace.

Adjust 2 piece caps.

Process in a boiling water canner for 10 minutes.