Peel and slice the peaches into 1-inch wedges, removing the pit. Place them in the freezer while you prepare your ice cream maker bowl. If using an ice cream maker with a freezer bowl, place it in the freezer now—it needs at least 12 hours to freeze solid, so plan ahead. If using a churning machine that doesn't require pre-freezing, you can skip this step. Having cold equipment is essential for proper ice cream texture and faster churning.
Open the can of coconut milk without shaking it—you'll notice the thick cream has separated from the liquid. Scoop out the solid coconut cream into a blender and add the frozen peach wedges, maple syrup, vanilla extract, lemon juice, and sea salt. Blend until completely smooth and creamy, about 1-2 minutes. The frozen peaches will start to soften during blending but that's perfect—it creates the right texture and chills the base. I like to taste the mixture at this point and adjust the lemon juice if the peaches taste overly sweet; a little extra brightness makes all the difference.
Pour the blended mixture into your pre-frozen ice cream maker bowl and churn according to your machine's instructions, typically for 25-30 minutes. The mixture should transform from a liquid into a soft-serve consistency as the churning incorporates air and keeps it moving to prevent large ice crystals from forming. Stop when it reaches a soft-serve texture—it will still be quite soft but should hold its shape when scooped.
Transfer the churned ice cream to a freezer-safe container and freeze for at least 30 minutes before serving. For a scoopable consistency similar to store-bought ice cream, freeze for 2-4 hours. I find that letting it sit out for 5 minutes before scooping makes it much easier to portion, especially if your freezer runs cold.