I love olive oil. It’s versatile, it’s easy to cook with, it’s even potentially healthful. And yet, alas, even olive oil in all its extra-virgin splendor lacks something: It’s not butter.
I really love butter. It’s a magical emulsion of water, fat, sugar, and protein, with a taste and texture that makes me glad to be alive. One of the greatest compliments a cook can hear is that a creation is “buttery.” (You never want to hear that something tastes “oily.”)
But you can’t cook with butter all the time. Magical though it may be, and as much as I love it, even I recognize butter’s limitations. You would, too, if you’d ever tried to improve on a french fry’s inherent goodness by deep frying it in butter. Sounds delicious, right? In reality, though, heating butter to the point at which you can fry sliced potatoes will give you a burnt mess and a screeching smoke alarm.
So why won’t butter cooperate? As with many things in life, the very attribute that makes butter so irresistible is also what makes it misbehave. Butter is about 80 percent fat, 16 percent water, and 4 percent milk solids. It’s those milk solids, which are made of protein, sugar, and minerals, that give butter its rich flavor. But when those tasty milk solids get too hot, they start to smoke and burn.
The moment at which fats burn is called the “smoke point.” For butter, the smoke point is 350ºF. For vegetable oil, which doesn’t have any milk solids, the smoke point is around 450ºF. All fats burn if heated enough, but the smoke point for each is different, depending on the amount of free fatty acids (found in all fats, as the name implies) and impurities. That’s why light olive oil, which is purified olive oil, has a higher smoke point than extra-virgin olive oil. All of which is a technical way of explaining why you can deep-fry foods in oil but not butter.
Perhaps at some point you were told by a convincing TV chef or read in an otherwise trustworthy cookbook that if you mix butter with oil, it will raise its smoke point. Unfortunately, you were told a terrible lie. Combining butter with oil can be good for flavor purposes, but it does not raise its smoke point.
Store-bought clarified butter isn’t widely available. What you’re more likely to see in Asian food stores or online is ghee (pronounced gee, with a hard G sound). A staple in Indian pantries, ghee is made from a cream that’s encouraged to sour a bit, so it has some extra tang compared with clarified butter. Also, the milk solids are browned slightly before being strained out, for a nuttier flavor.
Adding oil to a pan of butter will spread out the milk solids, but they’re still there and they’re still going to burn. The myth persists that mixing butter and oil raises butter’s smoke point for one simple reason: Since the milk solids are dispersed over a larger surface area, swimming in all that oil, it’s not as obvious when they start to smoke and burn.
Before you despair too much over the fact that anytime you cook at 350ºF or above you and butter must part ways, let me offer this one bit of encouragement: clarified butter.
Clarifying butter is a simple enough process that involves removing those troublesome milk solids along with much of the water. Then, butter behaves more like oil and can be heated to about 400ºF without fear of smoke or burning.
Pick up a stick of butter and you may wonder how to take out the milk solids and water. But it’s actually very easy. As we said before, butter is an emulsion.
If you’ve ever had a hard time making a Hollandaise sauce, now’s your time to shine. Here’s why: When you make an emulsified sauce, like Hollandaise, you are attempting to link oils and water-type liquids together, often with other flavors. If you don’t do everything just so, the sauce breaks. When you clarify butter, you are intentionally breaking the emulsion.
Let the clarifying begin. Heat the butter in a small saucepan over medium-low heat. Simmer slowly to boil off the water, 10 to 15 minutes. The white foam that forms on the surface is the milk solids (some may also sink to the bottom). Skim off the foam and then strain the liquid through cheesecloth into a clean container to filter out the solids that have sunk. You can store your golden clarified butter in the refrigerator, and it will last even longer than regular butter if kept airtight.
You would think that being able to raise butter’s smoke point would have me dancing in the streets. But the mixed blessing of clarifying is that removing the milk solids from butter also removes some of its delicious essence, the je ne sais quoi that gives it that wonderful, milky richness. Also, clarified butter can’t be used in baking without making
adjustments for the loss of water.
The process of clarifying does a good job of making butter a more versatile player in the kitchen (I use it for sautéing vegetables over high heat), but limitations persist—it can’t be heated as high as many oils, isn’t always at hand, and can be pricey if you buy it. That’s why olive oil tends to be my go-to fat for cooking. Although the butter dish is never far away. butter with oil can be good for flavor purposes, but it does not raise its smoke point.