Pick dandelion heads on a dry day, avoiding the green base to prevent bitterness. Rinse petals in cool water, then drain in a colander.

In a medium saucepan, bring 4 cups of water to a simmer. Add the petals, remove from heat, and let steep for 30 minutes.

Strain the infusion through a fine mesh sieve or cheesecloth into a bowl, pressing petals gently to release every drop.

Measure 3 1/2 to 4 cups of the liquid; add water if necessary.

If using powdered pectin, mix it with 1/2 cup of sugar to prevent clumping.

Pour the dandelion liquid and lemon juice into a heavy-bottomed saucepan. Bring to a full boil over medium-high heat.

Stir in the pectin-sugar mixture and return to a rolling boil.

Quickly stir in the remaining sugar, boiling hard for 1–2 minutes while stirring constantly.

Test for set by placing a small plate in the freezer, spooning a dab of jelly, and checking after 30 seconds.

Remove from heat and skim foam. Ladle jelly into sterilized jars, leaving 1/4 inch headspace. Process in a boiling water bath.

Let jars cool upright for 12–24 hours. Share on toast, with cheeses, or as gifts.