What Is Oleo, and Why Is It Found in So Many of My Grandma's Recipes?

My grandmother kept her recipes in a small blue binder that was definitely too cramped for the job.

Originally meant to house a neatly organized collection of family recipes, the binder became more of a catch-all for ingredients and hastily written steps on random scraps of paper.

The recipes, long buried under boxes of my grandmother's belongings, were recently rediscovered during an unplanned cleaning spree in the basement.

Aside from a few outdated gelatin salads, most of my grandmother's recipes would still feel right at home on a contemporary dinner table as they did in her kitchen decades ago.

While times may evolve, the fundamental ingredients we use in cooking (for the most part) remain unchanged.

However, one notable exception appears in many of her desserts: Oleo.

Like any curious millennial, I took to the internet to uncover what this unfamiliar ingredient is all about. Here's what I discovered:

What Is Oleo?

"Oleo" is simply another name for margarine (or oleomargarine). That's it, nothing more to it.

It’s still in use today, though it’s not as prevalent as it once was.

So, What Exactly Is Margarine — And What’s Inside It?

Margarine is a butter alternative made from vegetable oils, water, and salt.

As explained in The Food Lover's Companion, the ultimate resource for food and cooking knowledge, oil must undergo a chemical process called hydrogenation to become solid.

This is where things start to get tricky, and since I’m no scientist, I’ll leave the explanation to the FLC:

"During hydrogenation, additional hydrogen atoms are added to unsaturated fats, creating trans fatty acids and turning the mixture into a saturated fat, effectively canceling out any benefits it had as a polyunsaturated fat."

Confused? Me too, but the key takeaway here is that margarine is essentially fake butter.

To make the substitute taste more like real butter, ingredients like cream, milk, and other additives are often mixed in (the idea behind products like I Can't Believe It's Not Butter!).

The FDA mandates that margarine must contain at least 80 percent fat and only ingredients deemed safe for consumption.

A Brief History of Margarine

In 1813, French chemist Michel Eugène Chevreul discovered margaric acid. At the time, scientists believed that three fatty acids — margaric acid, oleic acid, and stearic acid — were the building blocks of most animal fats.

Margarine was born out of a competition held in 1869 by Emperor Napoleon III: the challenge was to create a butter alternative that was cheaper and more accessible.

Hippolyte Mège-Mouriès won the contest that year by patenting his creation, oleomargarine.

Gradually, the affordable alternative made its way across the seas.

In 1850, California gold miner John Steele shared his experience with margarine.

"(He) made butter from tallow and lard, and it resembled real butter so closely that ... I couldn’t tell the difference," Steele wrote. "But he fooled no one; he sold it for what it was. He never revealed how it was made, and I don't know if he was the original creator of oleomargarine."

Thanks to our growing understanding of trans fats, most modern margarines are now made from plant oils and are packed with healthy mono- and polyunsaturated fats.

Margarine vs. Butter

Butter, produced by churning milk, has been a key part of our diets for thousands of years. In contrast, margarine is a heavily processed substitute for butter.

Butter became a subject of controversy in the 1970s when its high saturated fat content was linked to heart disease. After health experts advised people to cut back on butter, many turned to margarine as a healthier option.

However, recent research has revealed that margarine may not be as heart-friendly as once believed: earlier versions of margarine contained high levels of trans fats, which increased LDL (bad cholesterol) and decreased HDL (good cholesterol).

In 2015, the FDA implemented a ban on trans fats in processed foods. Today, most margarines are made from plant oils and are rich in healthier fats.

There's still some ongoing debate about which ingredients are considered "good" and which are deemed "bad."

So, what’s a health-conscious baker to do? As I'm not a scientist, here's an explanation from Harvard:

"From a heart disease perspective, butter is still a food to be used sparingly, mostly due to its high saturated fat content," according to Harvard Medical School. "Margarines, however, are trickier to categorize. The older stick margarines turned out to be 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 okay, but you should still use them in moderation as they remain calorie-dense."

Margarine can often replace butter in recipes, but trust your own judgment. When it comes to flavor and texture, however, butter will always be the winner.