Juice the Lemons and Pineapple: Juice the lemons to obtain 1 cup of fresh lemon juice. If using fresh pineapple, blend the pineapple chunks and strain to get 1 cup of fresh pineapple juice. Alternatively, you can use store-bought pineapple juice.

Mix the Juices: In a large pitcher, combine the fresh lemon juice and pineapple juice.

Add Sugar: Stir in the granulated sugar until it is completely dissolved. Taste and adjust the sweetness by adding more sugar if needed.

Add Water: Add 4 cups of cold water to the pitcher and stir well. Adjust the dilution by adding more water if the lemonade is too strong.

Chill: Refrigerate the pineapple lemonade for at least 1 hour to let the flavors meld together and to chill it.

Serve: Serve the pineapple lemonade over ice cubes in glasses. Garnish with pineapple slices, lemon slices, and fresh mint leaves if desired.