Stir together lemon juice and sugar in a small bowl. Let sit 5 minutes to dissolve the sugar.
Add the cream, milk, and lemon extract an whisk to combine. Cover with plastic wrap and chill for at least 2 hours, or overnight. Whisk to combine before adding to ice cream maker.
Pour into cold ice cream maker and churn until thick, soft-serve consistency. Add to an airtight container or loaf pan covered tightly with plastic wrap. Freeze 3-4 hours before serving.
Notes
Tips for Storing
Store in an airtight container. Press a piece of plastic wrap directly onto the surface of the ice cream before putting the lid on. This prevents ice crystals from forming on top.
Use a shallow container. A wider, shallower container means the ice cream freezes and scoops more evenly than a deep, narrow one.
Best within 2 weeks. Homemade ice cream doesn't have stabilizers, so it's at its creamiest within the first week or two. After that, it can get icier.
Let it sit before scooping. Pull it from the freezer and let it sit at room temperature for 5 minutes before scooping. It makes a big difference.
Don't refreeze melted ice cream. If it fully melts, don't refreeze it. The texture won't recover and the dairy safety window has passed.