Slice all lemons in half and squeeze out every drop of juice using a citrus press or citrus squeezer. Strain the juice through a fine mesh strainer to remove seeds and pulp. Set the juice aside. Reserve the spent peels for citrus cleaning vinegar if desired (see notes).

Rinse strawberries thoroughly under cold water. Remove the hulls and roughly chop the berries so they blend easily and smoothly.

Add the strained lemon juice and chopped strawberries to a blender. Blend on high until completely smooth. If your blender is small, work in batches.

Pour the blended mixture into a large heavy-bottomed saucepan. Add 2 cups of sugar and stir to combine. Heat over medium, stirring frequently, until the sugar is completely dissolved. Do not boil. Taste the concentrate and add additional sugar one tablespoon at a time until it reaches your desired sweetness. Remove from heat.

Prepare your water bath canner and bring it to a simmer. Ladle the hot concentrate into sterilized pint jars leaving 1/4-inch headspace. Remove any air bubbles with a bubble remover or thin spatula. Wipe the jar rims clean with a damp cloth. Apply lids and screw on rings to fingertip tight — not over-tightened.

Lower jars into the boiling water bath canner. Process pint jars for 15 minutes at sea level (see notes for altitude adjustments). When processing time is complete, turn off the heat, remove the lid, and let jars rest in the canner for 5 minutes before removing.

Remove jars and place on a towel-lined counter, leaving at least 1 inch of space between jars. Do not disturb for 12–24 hours. You should hear the satisfying pop of each lid sealing as they cool. After 24 hours, press the center of each lid — it should not flex up and down. Any unsealed jars must go into the refrigerator and be used within 2 weeks.

To serve

Mix 1 pint (2 cups) of concentrate with 3 pints (6 cups) of cold water for one half-gallon of strawberry lemonade — approximately 8 glasses. Stir well, pour over ice, and enjoy.