Shortening is a fat and fats are solid at room temperature. Oils are liquid at room temperature. Ah, if it were only that simple….

Generally the use of the word shortening in this country now refers to hydrogenated vegetable oil – of a vegetable oil made solid through the chemical addition of hydrogen. In a broader sense, shortening is any fat or oil that is used to break up the gluten sheets that would form when water and flour are combined. The shortening is added in some significant amount, it surrounds the flour molecules and keeps water from combining with them and forming gluten. It is added to make to make pastry crumbly and crisp, and not tough and chewy.

In less recent times, butter and lard were the shortenings of choice, with margarine eventually elbowing its way in.

Oils can be and have been used as shortening, but they tend to produce oily and mealy results, not crumbly and crisp. But, through hydrogenation, oils were transformed into a flavorless fat, and that became the de facto shortening for a couple generations of American bakers (and most bakeries). Because vegetable shortening is pure fat and does not contain the water that is in butter and margarine, it does a better job of blocking the formation of gluten.

The process of hydrogenation or partial hydrogenation turned the oil into a saturated fat while creating trans fats, which caused all kinds of health concerns, and for a while (and for many people still) there was a mini rebellion against the use of vegetable shortening. Within the past couple of years, the major manufacturers of vegetable shortening have changed their processes so that vegetable shortening is now trans-fat free.

In spite of the fact that Europe gave us shortbread and shortcake, Europeans have never taken a shine to our vegetable shortening, and it is very difficult to find it in the rest of the world.

If you must have a black-and-white answer, no, canola oil is not a shortening.