This chapter is all about quick ways to add flavor, from its most basic building blocks — oil, vinegar, herbs, and spices — to the sauces, toppings, chutneys, chile pastes, and vinaigrettes you can make from them. In a trend that was starting when the first edition of this book came out, the movement toward vibrant, fresh flavor continues and the recipes in this chapter will serve as a flavoring arsenal to put spectacular finishing touches on most anything you make.
When you cook with oils, their differences affect the flavor and texture of the food. But when you use them raw, whether in dressings or as a last-minute drizzle, the strongest-tasting ones act as a true seasoning.
Unless it states otherwise on the label, assume that the oil was chemically extracted. This means that the raw materials (seeds, corn, soybeans, etc.) were crushed, washed in a petroleum solvent called hexane, then put through a complicated refining process that includes high heat. A residue of hexane remains, even though you won’t find it listed on the label as an ingredient. The FDA deems this residue insignificant and harmless, but I prefer to avoid it.
Instead, I look for oils that are expeller pressed or, better yet, cold pressed. Expeller-pressed oils are extracted using a screw press; heat is also involved, caused by the friction produced by the tremendous pressure needed for extraction, though it is much less than the heat used in chemical extraction. The same process is used for cold pressing, which should take place in a temperature-controlled environment. Unfortunately the term is not regulated in this country, so it’s hard to know how much it’s worth. (In Europe, “cold-pressed” olive oil can’t be heated above 80°F — barely warm — during extraction.)
Other terms to look for on labels to avoid chemically extracted oil are: unrefined, mechanically pressed, and organic. By law, neither hexane nor GMO products may be used in the extraction of oil labeled organic.
All oils contain a combination of monounsaturated, polyunsaturated, and saturated fats, in differing ratios. Olive oil, for example, is the best known for being high in monounsaturated fats; avocado and canola oil are also largely monounsaturated. Walnut oil and flaxseed oil contain a higher percentage of polyunsaturated fats, and coconut and palm oil are mostly saturated fat.
Both monounsaturated and polyunsaturated fats are viewed by the health community as being beneficial or “good” fats. Multiple studies have drawn correlations between diets high in monounsaturated fats (the Mediterranean diet) and a low rate of heart disease. Polyunsaturated fats (there are two types: omega-3 fatty acids and omega-6 fatty acids) are considered “essential” fats, meaning they are necessary for life function. Studies indicate that these two types of polyunsaturated fats can protect against heart disease and stroke, as well as provide other health benefits. However, in general, we Americans eat way more omega-6 than omega-3s — largely because omega-6 oils are used in most frying — and that’s thought to be a problem. If this concerns you, avoid soy, corn, cottonseed, safflower, and sunflower oils, especially the chemically refined varieties.
Saturated fats (which are also found in cheese, whole-milk dairy products, and red meat) are controversial. For the longest time, they were thought to promote heart disease, but the most recent evidence is conflicted. I prefer using and eating saturated fats over highly processed vegetable oils (like soy or corn oil), but for the most part I use olive and peanut oils.
Trans fats, found in hydrogenated or partially hydrogenated fats (liquid fats that have been processed to be solid at room temperature, including most vegetable shortening and margarine) and in many highly processed foods, have been shown to increase bad cholesterol, reduce good cholesterol, and contribute to the onset of diabetes, stroke, and heart disease. Avoid them. This is becoming easier as regulations against using them become stronger and manufacturers become wiser. However, according to the FDA rule presently in effect, foods labeled “zero trans fat” may still contain less than 0.5 gram of trans fat per serving; this will continue to be the case until 2018 when the FDA’s full ban on trans fats is supposed to go into effect.
All of these oils contain a greater percentage of monounsaturated fat than polyunsaturated or saturated fat:
These oils contain more polyunsaturated fat than monounsaturated or saturated fat:
These oils are more than 50 percent saturated fat:
Rancid oil tastes bad, and might even be bad for you. When oil starts to turn, it oxidizes, a process that converts some of its components into free radicals, which can cause cell damage when consumed. Since cold-pressed oils — which are the best oils — spoil fastest, you have to watch out for this.
But it’s easy to keep oil fresh: Keep oil in a dark, cool place, preferably not in clear glass. If you buy large quantities, put a pint or so in a bottle and keep the rest in a dark place or, even better, in the refrigerator. If you do store your oil at room temperature, smell it after a month or 2 before using it. You’ll know when it’s rancid; if it is, toss it.
If oil gets hot enough, it will smoke (this temperature is called its “smoke point”) and if heated enough, will eventually catch fire. The smoke point can vary from 225° to 450°F, depending on the oil. Obviously you want to avoid starting a kitchen fire, but beyond that, oil heated to smoking has off flavors, loses its potential health benefits, and may even be higher in free radicals. When cooking with any oil, watch the pan carefully and adjust the heat as needed.
Knowing an oil’s exact smoke point is helpful, but in reality few home cooks ever use a thermometer for anything other than deep-frying. Let your senses be your guide. Oil becomes more fragrant as it gets hot, and when it’s ready for cooking the surface begins to ripple and shimmer. Tilt the pan a bit and you’ll notice that the oil is thinner than it was straight from the bottle. Those are the signals that it’s ready for cooking, and nearing its smoke point. Adding food automatically lowers the temperature of the oil, especially if your ingredients are cold.