Bring 4 cups of 4 cups 热水（用于冲泡） to a boil in a Saucepan or Kettle. Remove from heat and let it rest for 1 minute — this brings the temperature down slightly (to around 200°F) and prevents the 4 红茶包，如立顿、Luzianne 或泰特莱 from becoming bitter.

Add 4 4 红茶包，如立顿、Luzianne 或泰特莱 to the hot 4 cups 热水（用于冲泡）. Steep for exactly 5 minutes. Do not squeeze or press the bags when removing them — this releases bitter tannins. Simply lift them out and discard.

Pour the hot brewed 4 红茶包，如立顿、Luzianne 或泰特莱 concentrate into a large Pitcher (Large). Add 4 cups of 4 cups 热水（用于冲泡） and stir to combine. This dilutes the concentrate to the perfect drinking strength.

Allow the 4 红茶包，如立顿、Luzianne 或泰特莱 to cool to room temperature (about 30–45 minutes), then refrigerate until fully chilled, at least 1 hour. Do not pour hot 4 红茶包，如立顿、Luzianne 或泰特莱 directly over 4 cups 热水（用于冲泡） — it will dilute and cloud the 4 红茶包，如立顿、Luzianne 或泰特莱.

While the 4 红茶包，如立顿、Luzianne 或泰特莱 brews, make the simple syrup (optional): Combine 3/4 cup ¾ cup 细砂糖 可调整 and 3/4 cup 4 cups 热水（用于冲泡） in a small Saucepan over medium heat. Stir until the ¾ cup 细砂糖 可调整 fully dissolves, about 2–3 minutes. Do not boil. Remove from heat and let cool completely. Transfer to a Quart Jar or bottle.

Fill tall glasses generously with 4 cups 热水（用于冲泡）. Pour the chilled 4 红茶包，如立顿、Luzianne 或泰特莱 over the 4 cups 热水（用于冲泡）, leaving a little room at the top. Sweeten with simple syrup to taste — start with 1–2 tablespoons per glass and adjust from there.

Garnish each glass with a 1 整个 柠檬 切成圆片或楔形 wedge or round and a sprig of fresh 4 株 新鲜薄荷 if desired. Serve immediately and enjoy!