The liquid ingredients are than tossed to form a dough. The purpose of cutting fat into the flour is to break up the fat and expose more surface area so as to contact a greater amount of flour particles. Between the pieces of fat in contact with the flour are particles untouched by the fat. Those particles in contact with the fat cannot be reached by water. Excessive development of gluten is prevented by finely cutting fat into the flour.
Water is added so it is distributed evenly over the entire mixture at once.
The mixture should be stirred immediately with wide circular motions to prevent parts of the dough from absorbing more water than other parts. After water is added, the extent to which the mixture is stirred also determines the toughness of the pastry due to the development of the gluten in the dough. Discuss the effect on pastry quality of using too much an amount of water in proportion to fat and flour ingredients. Account for the differences in pie crust pastry when milk is substituted for water as the liquid.