In a small saucepan over medium heat, stir together the sugar, 1/4 cup water, and lemon juice and zest. Bring to a simmer and stir to completely dissolve the sugar. Remove from the heat and cool completely.
In a large pitcher, stir together the brewed tea with the lemon simple syrup and 1 cup cold water. Stir in the bourbon if using and pour over crushed ice in glasses.