Rhubarb Pie with Brown Sugar

Most rhubarb pies call for white sugar, sometimes a lot of it, to balance the rhubarb’s aggressive tartness. This version uses brown sugar instead, and the swap changes everything. The molasses notes in light brown sugar add caramel depth that white sugar simply doesn’t have, complementing the rhubarb’s earthy character rather than just sweetening it.

Whole lemon slices are layered through the filling, not just juice or zest. As the pie bakes, the lemon slices soften and impart their oils into the syrup, while their bitter pith breaks down into something almost candied. This is unusual but worth it. The lemon doesn’t make the pie taste lemony so much as it brightens every bite of rhubarb without taking over.

The layering technique creates concentrated zones of flavor. Rhubarb, then sugar mixture, then lemon, repeated until you’ve built three distinct layers. As the pie bakes, the sugar caramelizes between layers and the juices mingle, creating a more complex filling than a simple stir-and-pour pie produces.

Pro Tips

• Slice the lemon paper-thin with a mandoline if you have one. Thicker slices stay too bitter even after baking.
• Use unpeeled rhubarb as specified. The colorful skin is the source of the pie’s beautiful pink color.
• Lattice the top rather than fully covering. The open weave allows steam to escape, preventing soggy filling.
• Cool at least 2 hours before slicing. Hot rhubarb pie filling is liquid and only sets up properly when cool.

Variations

• Use dark brown sugar for an even more caramel-forward filling with a slight molasses bite.
• Replace half the rhubarb with strawberries for the classic spring pairing.
• Brush the lattice crust with egg wash and sprinkle with raw sugar before baking for a sparkling, golden finish.