I'll make this very simple, and show you how butter is made, followed by how that plasticky other yellow stuff is made (getting the hint yet?).
This from Tom Naughton:
To make butter...
Milk a cow.
Skim off the cream.
Churn the cream until it’s thick and chunky and tastes awesome.
And as Naughton says, "That’s a food Mother Nature would indeed recognize." Indeed. And margarine, how is that made? Well, slightly differently.
Farmers grow seeds.
The seeds are harvested.
The seeds are crushed to extract some of the oil.
The rest of the oil is extracted by mixing the seeds with hexane, a chemical solvent.
The hexane is (supposedly) all removed.
The oil is pumped full of hydrogen gas and nickel powder. (Even the margarine makers know hydrogenated oils are a tough sell these days, so they may skip this step. I don’t know what, if anything, has replaced it.)
The remaining oil is subjected to heat and high-pressure CO2 gas.
The oil is mixed with sodium hydroxide and passed through a centrifuge.
The oil is mixed with water and passed through another centrifuge.
At this point, the margarine is a gray, speckled, oily mass that doesn’t smell so good.
The oil is mixed with hydrated aluminum silicate that binds to and filters out the unwanted pigments.
The mix is heated again and the oil is extracted.
The oil is passed through a steam distillation chamber to remove unwanted odors.
Yellow food coloring and artificial flavors are added.
Obviously the folks who want to sell margarine want you to think margarine is healthy and butter is bad, which is why they peddle half truths. Don't believe 'em, and if you insist on consuming margarine, make sure it doesn't involve hydrogenation. If you think this isn't important, think again. This stuff that we are eating, that we don't think about, is lethal. It's literally killing us. Want a graph or some stats to prove it (because maybe you think the process of making margarine doesn't sound harmful or too unnatural...):