Pick the dandelions, snip off the stem and green collar and rinse in cool water. Place petals in the one-gallon jar and pour the boiling water over them.
Let stand overnight.
In the morning, strain the liquid through cheesecloth, being sure to squeeze the flowers to remove all the juice. Combine dandelion juice with strained juice of lemons. Add juice to frozen raspberries and sugar. Bring mixture to a boil and simmer for 20 minutes.
Pour mixture back into jar, cooling to lukewarm temperature. Add yeast cake. Stir until yeast dissolves, cover the jar, and let mixture ferment for 10 days or until hissing subsides.
Using a double layer of cheesecloth, strain the liquid into a cider jug and let stand for 3 days.
Strain liquid again and place into quart wine bottles with screw-on caps, but DO NOT tighten the caps. Let the wine stand for awhile and then cap the bottles.
Age until December.