November 04, 2006
Jon writes: I'm trying to find a recipe for pie crust made with olive oil instead of butter / vegetable shortening. My experiments so far have been disappointing. Do you have any ideas?
Dear Jon: This relationship really isn't going to work out. You bring up a very complex and difficult subject which gets into the current debate over saturated fats, the proper use of animal and vegetable lard, etc. Lets begin with a bit of history. The first doughs which were eaten were unleavened flatbreads which are still extant as Indian roti, Greek pita, etc. Fermented dough was used to make a leavened bread by 4000BCE. Kneading caused springy gluten molecules to join up making a tough and elastic dough which would rise with the gas caused by fermenting.
But what if you do not want a tough dough which can rise, but a thin crust which is flaky; in other words a pastry. Adding fat will weaken gluten molecules by preventing them from bonding to each other, so adding fats to a dough will "shorten" it, making the final product more tender and flaky.
In crumbly pastries such as cookies, pate prisee, etc., the food comes apart in small irregular particles. Crusts which have a crumbly character instead of a flaky one, such as graham cracker and shortbread are made with melted butter or a liquid fat such as a vegetable oil. The liquid fat coats the grains of starch and further weaken the dough, creating crumbs. Olive oil would work fine in this kind of crust.
In flaky pastries such as the typical American pie crust, a bite should produce small, irregular thin flakes. A solid fat separates flattened layers of dough so that they cook into separate layers of pastry. One of the keys to making crust is to keep the fat solid by chilling it and minimizing over handling with warm hands. In order to keep the layers of fat and dough separate, the fat must be solid. That is why olive oil will not work. You might get away with a vegetable lard mixed 50-50 with olive oil if the mixing bowl and all ingredients are very cold to keep the fat mixture solid.
The ultimate laminated pastry is puff pastry, phyllo or strudel or laminated breads such as Danish and croissants where a bite produces very thin layers which are crispy or have the soft chewiness of bread. Again, the fat must be kept solid, the dough chilled.
Traditionally, before we worried about cholesterol, the better pie crusts used the fats which were hard at room temperature such as beef fat. These fats are solid because they are saturated with hydrogen. Vegetable oils are liquid because they contain double bonds. In an industrial process these oils can be subjected to heat, pressure and hydrogen to break these bonds creating a hydrogen saturated vegetable fat (hydrogenated). This otherwise liquid fat is now solid at room temperature and is called margarine or vegetable lard and can be used to make pie crust. You could take olive oil and hydrogenate it to a vegetable lard and use it to make a great pie. The trouble is that saturated fats are suspect health-wise.
The other problem with liquid oils is that a pasty made with them will "leak" oil out of the packaging. This is why they have poor shelf life, must have more expensive packaging and are not favored by the big food companies.
If you would like to try an oil pie crust, which will be more crumbly than flakey, see below:
1/3c olive oil
1c unbleached flour
2tsp baking powder
Put oil and water in a medium saucepan and bring to a boil. Add your combined dry ingredients and stir quickly until a ball of dough is made. Place in a pie pan and press.