Place the flowers in a large bowl or quart mason jar.
After the tea cools put it in the refrigerator for 24 hours. Then the next day, strain the flowers from the tea using a fine mesh sieve, cheese cloth or coffee filter.
Add the lilac tea to a large pot or saucepan and add pectin and sugar.
Turn off the heat and ladle the hot jelly into the canning jars.
Fill the jars to 1/4 inch headspace. Wipe jar rims with a damp cloth or wet paper towel and remove air bubbles. Process in hot water bath.