Using a vegetable peeler, remove zest from 1-2 lemons in wide strips, avoiding white pith. Juice the lemons (about 3 Tbsp from one lemon, 5-6 Tbsp from two).

Place strawberries, water, lemon zest strips, and lemon juice in a large saucepan. Bring to a simmer over medium heat, mashing gently. Cook 10-15 minutes until fruit has broken down.

Transfer to a dampened jelly bag or cheesecloth-lined strainer. Let drip undisturbed for at least 2 hours. Do not squeeze. Measure 4 cups juice.

Pour juice into a large, deep saucepan. Whisk in pectin until dissolved. Bring to a full rolling boil over high heat. Add sugar all at once, return to a full rolling boil, and boil hard for exactly 1 minute, stirring constantly.

Remove from heat and skim foam. Ladle hot jelly into prepared jars, leaving 1/4 inch headspace. Wipe rims, center lids, and apply bands to fingertip tight.

Process in a boiling water bath canner for 10 minutes for half pints, adjusting for altitude. Let stand in canner 5 minutes before removing.