I got this recipe from HERE and didnt change a thing. It is AWESOME!!! And it is a good family project collecting the 12 cups you need LOL.
12 cups dandelion flowers, clipped as close to the base of the flower as possible and rinsed well
6 cups water
1 whole lemon
3 cups sugar
Chop lemon into small pieces(the WHOLE thing, skin and all)
Remove from heat and allow to steep overnight.
Strain the entire concoction into a large bowl to catch all the juice(cheese cloth, thin cotton towel, paper towel or coffee filter in a colander works well.)
Squeeze the flowers out well.
Place liquid in a sauce pan and add 3 cups sugar. Bring to a boil, stirring often. Reduce heat and simmer, cook 1 1/2 - 2 hours until very thick.
Store in the fridge.