In a mixing bowl, combine flour and salt.
Cut the cold butter into small pieces and add to the flour.
Using a pastry cutter, mix until the mixture resembles coarse crumbs.
In a separate bowl, mix cold water and lemon juice.
Gradually add the water mixture to the flour mixture.
Stir until just combined; do not overmix.
Form the dough into a rectangle, wrap in plastic, and refrigerate for 1 hour.
On a floured surface, roll out the dough into a rectangle.
Fold the dough into thirds, creating layers, and roll again.
Repeat rolling and folding 3-4 times for flaky layers.