Trans Fats: Episode 1

You know enough about fats and frying now to know why solid fats are valuable to the food (and especially baking industry). Solid fats are durable and far less prone to both “weeping” and rancidity than liquid oils. Which means foods that contain them are less prone to spoilage, and that’s good for pretty much everybody. The problem is that historically solid fats — because they were derived from animals — were more expensive than liquid oils. Wouldn’t it be nice, people once thought, if we could find a way to make liquid fats solid?

That way was discovered in 1902 when a German chemist by the name of Wilhelm Normann bubbled hydrogen through plant seed oil in the presence of a catalyst metal. The process, called hydrogenation, had the effect of saturating unsaturated fats. Which is to say, it caused unsaturated fatty acid (hydrocarbon) chains to pick up hydrogen atoms, and so become firmer.

The only thing odd about this new fat (which Proctor & Gamble started to market a few years later under the name “Crisco”) was the shape of some of the fatty acids in its molecules. Normann found that while he could add hydrogen atoms to unsaturated fatty acid chains, he couldn’t control the configuration of those atoms once they attached. No big deal though, since the fat performed exactly like all other solid fats. Better, really. It would be many, many decades before anyone thought to question the safety of this very important process.