Knowing how to make a vinaigrette is a foundational kitchen skill. If you memorize your basic ratio of oil to acid (usually 3 to 1) and keep a few flavorful dressing ingredients on hand (mustard, honey, fruit jam, herbs and spices, etc.), you can whip up fresh, easy homemade vinaigrettes on the fly. Critical to your dressing success, though, is your whisking motion.
Get good enough at this technique, and you can save time and effort cleaning a food processor every time you make a salad. To emulsify oil and vinegar into a homogeneous vinaigrette by hand, there’s only one way to whisk: side to side.
ATK testing shows that vigorous side-to-side whisking emulsifies vinaigrettes better than circular stirring or the looping motion you’d use to beat eggs. That’s because a side-to-side stroke is an easier motion to repeat rapidly and with force. With side-to-side whisking, you’ll generate more whisk strokes per minute than you would with other motions. See for yourself: