Prepare the pie dough and chill.

Combine peaches, blackberries, lemon juice, and salt.

Mix ginger, flour, and brown sugar; toss with the fruits.

Let the mixture rest for 1 hour.

Preheat oven to 350F.

Combine egg white and water in a small bowl.

Remove pie crusts from the refrigerator.

Brush egg-white mixture over the bottom pie crust.

Add the fruit filling, mounding in the center.

Cover with the top crust.

Trim overhang to 1 inch.

Moisten crust edges, press together, and turn under.

Crimp the edges decoratively.

Cut steam slits in the top crust.

Brush the top crust with egg-white mixture.

Sprinkle with granulated sugar.

Bake for 60 to 70 minutes, until golden and juices are bubbling.

Cool on a rack before serving.