There are many vegetable fats to consider when we walk down the grocery aisle these days. Do we cook with olive oil or should we use canola? What’s the difference between sunflower and safflower? Though these are all produced from various plants, they differ considerably in their application once we step into a kitchen.
Oil is labeled often by its smoking point. And just what is the smoking point? As heat is applied to an oil, the fat begins to break down and decompose into fatty acids. The smoking point is the temperature at which decomposition begins for each oil. One of the fatty acids that is released is called acrolein and is responsible for the acrid flavor that we taste in burnt food. Which oil you’ll want to use depends entirely on the dish you’re cooking. Let’s look at some options:
Frying
I think we can all agree that frying is a relatively high-heat endeavor, yes? Indeed, when we discuss the verb to fry we are mostly looking at temperatures above 375 degrees. In this case, you need an oil with a terribly high smoke point. What’s best for this kind of cooking? Safflower, soybean, peanut, corn, sunflower, canola, and toward the bottom of the list, grape seed. Each of these oils will resist the urge to smoke and break down the far longer than other vegetable oils.
Sautéing
Are you cooking dinner in a sauce pan? This is a form of relatively high heat, but not as high as frying. In this case you can use all of the oils we’ve already discussed as well as the most charming sesame oil. But, of course, the heavy hitter in this category is extra virgin olive oil.
And now we must dip our toe into the confusion and controversy that surrounds olive oil.
When you see something labeled extra virgin olive oil, that means the oil has been harvested without the use of heat or chemicals. This oil is technically, the finest, most pristine version of olive oil. It is often signified by a greenish color, though not always. Olive oils are rated on their level of oleic acid (which is to say, the percentage of fat that has broken down into fatty acids). You certainly can sauté with extra virgin olive oil, but it is best saved for salad dressings, dips, and cold dishes.
You might find oil labeled simply “Virgin Olive Oil.” These are the next step down in quality, though still produced without heat or chemicals. It might come from a second pressing. This oil will have a less pronounced oil flavor and a slightly higher percentage of oleic acid. This oil is terrific for everyday sautéing, cooking that might otherwise bury the flavor of an expensive extra virgin oil.
My favorite oil to sauté with is grape seed oil. It is, indeed, pressed from the seeds of grapes and is consequently a wonderful by-product of winemaking.
Baking
Do you opt for vegetable oil in your baked goods instead of butter or lard? You are not alone! Oftentimes you’ll see recipes call for vegetable oil, but what oil are they referring to? When it comes to baking you want something with a neutral flavor and a medium smoke point. Coconut oil, when refined, has very little aroma and can be terrific in muffins and breads (particularly if you’re trying to avoid butter). Canola oil also has its place in the baking world, it has very little taste. I often reach for sunflower oil when baking. Like the others on this list it has a neutral flavor and a moderate smoke point, and tends be slightly higher quality than Canola oil.
Side note: Are we all aware that Canola oil is thusly called because of its invention in Canada? Rapeseed oil was abundant, though believed be slightly toxic due to its concentration of glucosinolates and erucic acid. Through traditional cross breeding, plant specimens with lower values of both chemical compounds were selected over and over until the new genetic variant was perfected. This new plant was dubbed Canola (Can from Canada, and Ola from oil).
Dressing
This is a particularly lovely category of oils. For the most part, oils that come from seeds and nuts have very low smoke points. But they are terrific to keep on hand because of their wide variety of flavors. Walnut oil, and pumpkin seed oil are delicious when drizzled over a finished dish, or whisked into a salad dressing.
Storage
Once you’ve stocked your kitchen with oils, how best to keep them? Well, we want to minimize the potential for these oils to spoil, or decompose. And in that case we have three enemies to defeat: heat, light, and oxygen. So, it is best to keep your oils in a dark, cool place (no higher than 70 degrees please, much closer to 60 if possible). Store them in dark, ceramic or glass bottles, and make sure they’re sealed off against the surrounding air.