In a small saucepan, combine granulated sugar and water. Heat over medium-low heat, stirring constantly, until the sugar completely dissolves. Do not boil. Remove from heat and let cool completely to room temperature.

Peel the kiwis and roughly chop them into chunks.

Transfer the chopped kiwis to a blender. Add the cooled simple syrup, fresh lemon juice, and a pinch of salt. Blend until completely smooth.

For an exceptionally smooth sorbet without any kiwi seeds, press the blended mixture through a fine-mesh sieve using a spatula into a clean bowl. Discard the collected seeds and pulp. This step is optional.

Cover the sorbet base and refrigerate for at least 1 hour, or until thoroughly chilled. This is crucial for optimal churning and texture.

If using an ice cream maker, pour the chilled mixture into the frozen bowl of your ice cream maker and churn according to the manufacturer's instructions, typically for 20-30 minutes, until it reaches a soft-serve consistency.

Transfer the soft sorbet to a freezer-safe container. Press a piece of parchment paper or plastic wrap directly onto the surface of the sorbet to prevent ice crystal formation. Freeze for at least 3-4 hours, or until firm enough to scoop.

If not using an ice cream maker, pour the chilled mixture into a shallow, freezer-safe container. Freeze for 30-45 minutes until the edges begin to solidify. Remove from the freezer and vigorously stir with a fork or whisk to break up ice crystals. Repeat this process every 30-45 minutes for 3-4 hours, or until the sorbet is uniformly frozen and firm.