In a saucepan, combine the sugar, lemon juice, and lemon zest.
Heat over medium heat, stirring continuously until the sugar has dissolved completely.
Cut the white chocolate into small pieces and place in a large bowl.
Bring to a boil, then cook for 10-12 minutes, stirring occasionally, until thickened and reduced by half to a pale honey color.
Remove the syrup from the heat and remove the lemon zest. Set aside.
In a medium pan, combine sweetened condensed milk and butter. Stir over low-medium heat until melted and combined, without boiling.
Remove the pan from the heat, and pour the hot condensed milk mixture over the white chocolate.
Pour the lemon syrup into the melted chocolate mixture. Add yellow food coloring (this is optional) and stir until all ingredients are fully combined and the mixture is smooth.
Pour the mixture into the prepared baking pan, spreading it evenly.
Let it cool to room temperature, then refrigerate for at least 2 hours or until firm.
Once set, remove the fudge from the pan using the parchment paper overhang.
Cut into small squares and serve. Enjoy your lemon fudge!
Notes
Choose Quality Ingredients: Use fresh lemons for the juice and zest to get the best flavor. Make sure your white chocolate is high quality, it really makes a difference!Mix Well: When you combine the condensed milk mixture with the melted white chocolate and lemon syrup, mix everything thoroughly. This helps ensure your fudge has a smooth texture and consistent flavor.Adding Color: This is totally an optional step, however, if you want a brighter lemon color, add yellow food coloring after everything else is mixed. Stir until the color is evenly spread.Cooling: Let the fudge mixture cool to room temperature before putting it in the fridge. This helps it set smoothly. Chill for at least 2 hours until it’s firm enough to cut.Cutting and Serving: Once the fudge is set, use the parchment paper to lift it out of the pan. Cut it into small squares with a sharp knife, cleaning the knife between cuts for neat edges.Storing: Keep your lemon fudge in an airtight container in the fridge. It will stay fresh for 1-2 weeks. For the best texture and flavor, let it come to room temperature before serving.