Zesty Lemon Vinaigrette

Before I left for a three-week vacation this past December, I frantically juiced all my lemons. I had 12 hours until my flight departed. My apartment was a chaotic mess. I still wasn’t completely packed… and somehow, my biggest priority was freezing lemon juice. My logic: They’re expensive and come from far away, and I just couldn’t stomach the thought of it all going to waste.

There are many ingredients I can’t live without, but few are as versatile as the lemon. I rely on their juice to brighten up salads, pastas, and beverages, and they have a starring role in my favorite lemon bars. What I make most with the fruit, however, is salad dressing. There aren’t many vegetables that don’t go well with the citrus, and keeping a jar of this punchy lemon vinaigrette in my fridge means I can easily toss together a salad at a moment’s notice. Plus: It lasts for a full month refrigerated, which means I can make it ahead so it’s always ready for speedy lunches and minimal-effort weeknight dinners.

This dressing is so straightforward it involves just one step—barely a recipe, really. Simply stir together the lemon juice and zest, honey, garlic, shallot, and salt in a large nonreactive bowl, then gradually stream in the olive oil as you whisk constantly to emulsify. The result is a creamy, invigorating vinaigrette that will even brighten up the dreary salad you may have picked up for lunch.

With brightness from both lemon juice and zest, this vinaigrette is a bold, bracing way to dress leafy greens and tender herbs. Because lemon peel contains many fragrant phenolic compounds—water-soluble antioxidant molecules—the resulting dressing is much more aromatic than if you were to use lemon juice alone. A finely chopped shallot and touch of honey bring a subtle sweetness that balances the lemon’s acidity and Dijon mustard’s spicy kick, while grated garlic lends a savory note.

The Importance of Emulsification in a Vinaigrette

Like oil and water, oil and acidic liquids like vinegar and this dressing’s lemon juice don’t come together—or stay combined—easily without a little help from an emulsifier like mustard, mayonnaise, or an egg yolk. 

When you properly emulsify dressing, you end up with a thick, creamy vinaigrette instead of a thin, runny sauce. But improved texture isn't the only advantage of an emulsified vinaigrette: Your dressed salad will last longer too. Kenji discovered as much when he put emulsified versus non-emulsified vinaigrettes to the test and found that greens dressed in plain oil and vinegar wilted faster than those dressed in an emulsified vinaigrette. One of his valuable insights from this test was that it was the oil—and not the vinegar—that wilted the leaves. By thoroughly blending the two into an emulsion, that wilting effect of the oil is lessened.

In the recipe below, Dijon mustard is the emulsifier that helps the vinaigrette stay blended for longer. Even with an emulsifier, though, a vinaigrette will likely separate after sittingfor several hours. Just give it a good whisk or shake before using to bring it all back together, and you’re good to go. As Kenji says, your vinaigrette only needs to stay bound long enough for you to enjoy your salad—and with this dressing recipe in your pocket, you’re likely to love it even if it’s an otherwise sad-desk-lunch salad.