Put shortening in a medium bowl and boil the water.
Pour water over shortening and blend till all the water is absorbed and the mixture is smooth.
Add the flour,salt and baking soda.I put the soda and salt in the first cup of flour and mix in one cup at a time in case you don't need all of the flour. Usually you do.
Once it is mixed and in one large ball, you can then cut this down to 3 individual balls of dough, wrap in plastic wrap and chill for at least 2 hours. If you want a larger pie crust, just do 2 balls of dough.
If you do not use all the dough it can be kept in the fridge for about a week or so or even frozen.
Bake these pie crusts up as you would any others. I usually bake them at 350-400 for 12-15 minutes, or till golden brown.
Follow instructions for double crust fruit pies when using those recipes.