What Is Oleo—And Why Is It In So Many of My Grandma's Recipes?

My grandmother kept her recipes in a too-small-for-the-job blue binder.

Though the binder was originally intended to hold an organized collection of family recipes, it became a dumping ground for ingredients and shorthand steps jotted quickly on loose pieces of paper.

The recipes, which sat untouched and buried beneath boxes of my grandmother's things, were rediscovered a few days ago during an impromptu basement purge.

Save for a few congealed salads, most of my grandmother's recipes would feel just as at home on a modern table as they did in her kitchen 40 years ago.

Times may change, but the basic ingredients we use (for the most part) stay the same.

One exception, though, is something that pops up in quite a few of her desserts: Oleo.

As any good millennial would do, I took to the internet to find out what this foreign-to-me ingredient is all about. Here's what I found:

What Is Oleo?

"Oleo" is another word for margarine (or oleomargarine). Nothing more, nothing less.

It's still used today, but it's not as common as it once was.

OK, So What Is Margarine — And What's In It?

Margarine is a butter substitute made of vegetable oils, water, and salt.

According to The Food Lover's Companion, the definitive guide to all things food and cooking, the oil must undergo a chemical transformation called hydrogenation in order to become a solid.

Things get complicated right about here, and I never claimed to be a scientist — so I'll let the FLC do the talking:

"During hydrogenation, extra hydrogen atoms are pumped into unsaturated fat, a process that creates trans fatty acids and converts the mixture into a saturated fat, thereby obliterating any benefits it had as a polyunsaturate."

Confused? Same, but all we really need to know here is that margarine is fake butter.

Cream, milk, and other food additives are often added to make the substitute taste more like the real thing (I Can't Believe It's Not Butter! was born of this concept).

The FDA requires that margarine must contain 80 percent fat and only safe ingredients.

Margarine History

In 1813, French chemist Michel Eugène Chevreul discovered margaric acid. Scientists believed that three fatty acids — margaric acid, oleic acid, and stearic acid — combined to form most animal fats.

Margarine was actually the result of an 1869 contest held by Emperor Napoleon III: Whoever could find an alternative to butter, which was both expensive and hard to come by, would win a prize.

Hippolyte Mège-Mouriès patented his creation, oleomargarine, that same year.

Slowly but surely, the cheap substitute made its way overseas.

California gold miner John Steele wrote of his margarine experience in 1850.

"(He) manufactured butter from tallow and lard, and it looked and tasted so much like real butter, that ... I could not tell the difference," Steel wrote. "However, he deceived no one, but sold it for just what it was. He never explained the process of its manufacture, and whether he was the originator of oleomargarine I do not know."

Because of our evolving knowledge about trans fats, most modern day margarines are made from plant-based oils and are rich in beneficial mono- and poly-unsaturated fatty acids.

Margarine vs. Butter

Butter, made from churning milk, has been a dietary staple for thousands of years. Margarine, meanwhile, is a highly processed butter substitute.

Butter became a hot topic in the 1970s, when its high saturated fat levels became associated with heart disease. After public health officials recommended consumers limit their butter consumption, many people switched to margarine.

Recent studies, however, have shown that margarine may not be the heart-healthy ingredient it was purported to be: Older margarines had high levels of trans fats that raised levels of LDL (bad cholesterol) and lowering levels of HDL (good cholesterol).

In 2015, the FDA banned trans fat in processed foods. Most margarines these days are made from plant-based oils and are rich in the better-for-you fats.

There's still some debate over which ingredient is "good" and which is "bad."

What's a health-conscious baker supposed to do? Again, I'm no scientist — so here's this explanation from Harvard:

"From the standpoint of heart disease, butter remains on the list of foods to use sparingly mostly because it is high in saturated fat," according to Harvard Medical School. "Margarines, though, aren't so easy to classify. The older stick margarines turned out to be clearly worse for you than butter. Some of the newer margarines that are low in saturated fat, high in unsaturated fat, and free of trans fats are fine as long as you don't use too much (they are still rich in calories)."

Margarine can often be used in recipes that call for butter, but use your best judgment. As far as taste and texture go, though, butter will always reign supreme.