Peel, pit, and slice the peaches. Toss the slices with 2 tablespoons of the granulated sugar and 2 tablespoons lemon juice, then let macerate at room temperature for 15–20 minutes.

Combine 1 cup granulated sugar and 1 cup water in a small saucepan. Heat over medium, stirring until sugar dissolves and the mixture is clear (about 3–4 minutes). Remove from heat and cool 5 minutes.

Add the warm syrup to the macerated peaches and blend until smooth, about 30–45 seconds. For an ultra-smooth sorbet, press the purée through a fine-mesh sieve into a bowl and discard solids.

If using the sugar-free option, dissolve 1 cup erythritol in 1 cup warm water instead of the granulated sugar syrup and proceed as above.

Chill the peach purée in the refrigerator until completely cold, about 45–60 minutes. Freeze in your ice cream maker according to the manufacturer’s instructions until it reaches soft-sorbet consistency, about 20–25 minutes.

Transfer the churned sorbet to a shallow, freezer-safe container, press a piece of parchment directly on the surface to prevent ice crystals, and freeze at least 2 hours to firm up. Let sit at room temperature 5–7 minutes before scooping.