Choosing the right cooking oil

B.B. (Before Baby), two oils lived in my kitchen: Extra Virgin Olive Oil for cooking & Vegetable Oil for baking. In my mind, the “extra virgin” meant “better” and Vegetable was the generally requested oil for any back-of-the-box brownie mix.

As adults, we’ve been trained to avoid or reduce our fat intake, but current research challenges the idea that a healthy diet is a low-fat or even specific-type-of-fat diet. In fact, our brains are comprised of 60% fat  — so you can imagine how critical they are  for the ever-developing brains of our babies. My daughter’s first food, breast milk, was full of good fats, and I wanted to be able to continue similar benefits as she began to eat more solid foods.

Here’s a breakdown of what constitutes a “healthy” oil, appropriate cooking temperatures and uses for various oils & some storage tips to keep your oil fresh, nutritious and flavorful.

What’s a healthy oil & what should I avoid?

Because different fats do have different “tasks”, I don’t believe there is an inherently “bad” fat when you eat fats in moderation as part of a well-balanced diet. Unfortunately, Western diets and lifestyles are not very balanced. As a general rule of thumb, I opt for unsaturated fats (traditionally what you’d think of as a “good” fat like avocados) and minimally processed oils (meaning unrefined and cold-pressed oils). I avoid or minimize my use of saturated fats, trans fats, hydrolyzed or partially hydrolyzed oils and refined oils (except for high temperature cooking).

Some of my favorite kitchen staples include: Avocado Oil, Extra Virgin Olive Oil and Walnut Oil.

How should different oils be used?

The number one way to damage an oil and reduce its health benefits (not to mention it makes food taste pretty disgusting) is by overheating or burning it. Every oil has a smoke point which is when the oil has reached a temperature that it can no longer withstand and the fats breakdown to release free radicals (not good for you) and Acrolein, a chemical that gives burnt foods their distinct flavor and smell. To avoid this, you should only heat oil to the point it is shimmering, but does not release smoke. And, in some cases, oils are best completely unheated (like walnut oil!) to maximize their nutritional value and taste. Check out the graphic above to see the optimal way to use my favorite oils.

What’s the difference between a refined and unrefined oil?

Unrefined oils are minimally processed and retain more minerals, enzymes and other healthful goodness. However, they tend to have shorter shelf lives and are best for low-temperature or non-heated uses like dressings or in smoothies. Refined oils go are highly processed and use temperature, bleach or other filtering methods to remove the healthful particles like minerals and enzymes, making the oil more neutral — meaning they tend to have longer shelf lives and also hold up to higher temperatures better.

How should I store oil to maximize its shelf life & flavor?

Oil can go bad, so if you’ve had a bottle of oil just sitting around for more than a month, give it a sniff and taste test. Does it smell and taste pleasant? If in doubt, throw it out! Also, as a oil “degrades”, its smoking point can be lowered and lose nutritional value. As a rule of thumb, keep all oils in cool, dark places and away from heat (hat clear container next to your stove is convenient but not the best spot for maximizing shelf life). Opt for a darker container (not clear) if sitting on your counter. For specialty oils (think Sesame, Walnut, etc.), store them in your refrigerator and consider the fridge as an option for any oil you will keep longer than a month.