Tallow to margarine

This is an intriguing introduction to how natural fats and oils have been transformed or replaced through chemistry and fossil fuel use. Every accessible natural lipid was once used as food and for critical household/industrial processes (lighting, lubrication, medicine, and so on).

That I have no use for tallow is an accident of modernity. Up until the early 19th century, essentially all oils and fats that humans used – whether as food, fuel, lubricant, or finish – were derived from plants and animals.

Were I presented with that lump of suet in 1824 instead of 2024, I would, after chopping some into my pudding, have rendered it for tallow and eaten the brown crackling (called greaves) in the rendering pot. I’d have molded the tallow into candles, or used it to grease my sewing thread or my rifle or the axles of my cart. At a larger scale, we used tallow for rolling steel (and still do) but lard for general metalworking. Mutton tallow was preferred to beef tallow in textile manufacture. Beginning in the 1550s, tallow candles and farthing dips were gradually displaced by whale oil, especially sperm oil, which remained liquid even in the depths of winter, but both remained in use into the 1800s.

Before we understood lipid chemistry, the pharmacopeia of naturally occurring fats provided myriad technological opportunities. Nature, it seemed, offered a substance for every conceivable need, awaiting only enterprise and exploitation (we also still believed in manifest destiny and the white man’s burden).

But humanity was also limited by the affordances of naturally occurring fats – the pharmacopeia was also a kind of planetary boundary. Modern, industrial-scale processes for manipulating the chemical structure of fats, for turning one lipid into another (fractionation, hydrolysis, and hydrogenation) were only commercialized in the late 19th century, having been enabled by the transition to fossil fuels.