1/2 cup coarsely ground coffee beans
4 cups water, divided
1 cup white sugar
Place coffee beans in a French press or large measuring cup; pour in 2 cups water. Let coffee steep, 8 hours to overnight.
Combine remaining 2 cups water and sugar in a saucepan; bring to a boil. Simmer until sugar dissolves, 3 to 5 minutes. Pour syrup into a container and transfer to the refrigerator.
Strain coffee using the French press plunger or through a coffee filter in a fine-mesh strainer. Pour 1/2 cup coffee into a glass of ice; sweeten with simple syrup.