Lemons: The 'secret' ingredient that makes everything taste better
When life gives you lemons, put them in everything.
Sometimes when I'm asked what the secret is to a dish I've made, the answer is a specific little trick I've picked up from my mother or a cookbook. But more often than not, the big secret is not a secret at all. It's lemon.
Adding lemon juice or zest to a dish, sweet or savory, changes its whole flavor profile. Suddenly, a pretty good tomato sauce is brimming with complexity, a blackberry pie tastes like it's packed with a thousand perfect berries and all of summer, and braised broccolini isn't just a convenient side dish — it's the best part of the meal. The citrus fruit contributes that glorious savor you can't quite put your finger on. Lemons are as crucial a flavor-enhancer as salt. But while salt is a mainstay in even the worst-stocked pantries, lemons are often overlooked.
On your tongue, salt and lemons work a similar kind of magic. Biochemically speaking, salty and sour taste receptors are relatively simple compared with their sweet, bitter and umami counterparts: Tasting salty and sour flavors depends solely on the detection of ions — sodium for salt, hydrogen for sour — whereas tasting other flavors depends on more complicated receptors. Acidity, like saltiness, also leads to an increase in salivation — both flavors literally make food more mouthwatering. Since tasting depends on saliva's power as a solvent, the presence of saliva on your tongue is necessary for your taste buds, and therefore your brain, to perceive flavor. The upshot is that a squeeze of lemon is as good as a dash of salt in bringing out the flavor of just about any food.
Besides making your mouth water, acidity cuts greasiness and heaviness and gives food a fresh, clean taste. Lemon juice can also change a food's texture to fit a variety of needs, as when macerating berries, tenderizing meat and "cooking" ceviche. Lemon juice contains citric acid, which helps break down fats, carbohydrates, and protein.
But lemons aren't just useful for their juice — the zest contains lemon oil, which is where you'll find the most flavor-bang for your lemon-buck hiding. This is especially handy in instances where you want to add flavor, but not additional liquid, as with pie crusts. And, unlike unsubtle salt, too much of which will strangle the flavors in your food, lemon juice and zest play nicely with bitterness, sweetness, piquance and umami, helping them reach their full potential.
Lemons are inexpensive, easy to find, consistent in quality and hard to use incorrectly. Picking good lemons isn't hard: They should be bright yellow in color, firm to the touch, smooth and heavier than you might expect considering their size. They should also be lemon-shaped. (Seriously. The closer it looks to the ideal of a lemon, the more likely it is to be perfectly juicy.) If you pick right, they'll last for several days at room temperature or even longer in the crisper drawer of a refrigerator.
How should you use lemon to improve your food? Squeeze it into soups, sauces and drinks. Toss it with salads, vegetables and pasta. Rub it onto pork, chicken and fish. Bake it into cakes, muffins and snacks. And add it to anything and everything containing mayonnaise.
For most dishes — with the obvious exception of baked goods and lemon-marinated meats and vegetables — a squeeze of lemon should be added right before cooking finishes. Cooking lemon for a long period of time will concentrate the flavor and can make it bitter. It can also dull the color of vegetables if added too soon, whereas it will brighten color if added at the end (so long as you haven't killed it with overcooking). If you do go overboard and your food tastes too sour, a tiny bit of sugar (just a pinch at a time!) should save the day, even in savory dishes.