In a medium-sized mixing bowl, blend the flour and salt together. Take one quarter (3 tablespoons) of each type of fat and rub it into the flour/salt mixture with your fingertips until it resembles cornmeal., Mix the lemon juice with the water, and stir into the flour/fat mixture until you have a soft dough. Turn the dough out onto a lightly floured surface and knead it until it's smooth., With a well-floured rolling pin, roll the dough out until it's about 7" wide and 21" long. If the dough sticks at any point, slide a bench knife or spatula under it and throw a little flour underneath., Take 3 tablespoons more of each type of fat and dot them over the top two-thirds of the dough. Fold the bottom third up over the middle third and the top third down over that. Wrap in plastic wrap and place in the refrigerator for about 15 minutes., After the dough has chilled, take it out of the fridge, unwrap it and roll it out for the second time, until it's about 7" by 21". Repeat with the next 3 tablespoons of each of the fats and fold as you did before. Chill the dough for 15 minutes., Repeat the process of adding the fats a third and final time. This time, before you chill the dough, roll and fold it for a fourth time, this time without adding any fat. Wrap and chill the finished dough for at least 45 minutes before using it.