Finely zest the lemon. Avoid the bitter white pith and try to just get the yellow zest on the outer edges.
Add sugar and lemon zest to a medium bowl. Use your fingers to rub the sugar granules into the lemon zest until fully combined and no clumps of lemon zest remain.
In a medium saucepan over medium heat, combine lemon sugar and lemon juice. Stir until sugar has dissolved. Remove from heat. Let cool completely. Strain out the solids.
Transfer to a glass jar and seal tightly with a lid.
Notes
Storage: Store in the refrigerator for up to 1 month.