Add the cubed peaches to a large pitcher and lightly muddle them just enough to crack the flesh and release aroma without turning them into purée, then add the honey, lemon juice, and fine sea salt and stir until the honey is fully dissolved and the fruit is evenly coated.
Pour in the ice-cold water to reach a total volume of about 3.2 liters, add the sliced peaches and lemons, and stir gently to distribute everything without breaking down the fruit.
Refrigerate for at least 1 hour for a clean, subtle peach character; for a fuller aroma, infuse up to 4 hours, but no longer, as peach loses clarity and becomes dull when over-infused.
Serve well chilled, straight from the pitcher or over ice if preferred.
