Combine the flours and salt in a large bowl
Add the cubes of butter and work the flour and butter together with your fingertips until the mixture resembles grainy crumbs
Add the water and mix until the dough clings together, adding additional water by the spoonful if too dry
Transfer to a floured work surface and knead the dough briefly with the palm of your hand
Shape into a rectangle about 1 inch thick
Cover and refrigerate for 1 hour
Roll the dough into a rectangle about 9 x 14 inches
Fold into thirds as if folding a letter for an envelope (first turn)
Mark each turn with a finger depression in the dough
Refrigerate for at least 40 minutes between each turn
Repeat rolling, folding, and refrigerating for a total of 4 turns, keeping the seam facing the same direction each time
Use in recipes calling for puff pastry
