From America's Test Kitchen
Order barbecue down South, and you won’t just get coleslaw on the side, you’ll get buttermilk coleslaw. Unlike all-mayonnaise coleslaw, buttermilk coleslaw is coated in a light, creamy, and refreshingly tart dressing. We wanted a recipe that showcased the best attributes of this side salad: a pickle-crisp texture and a tangy dressing.
To prevent watery coleslaw, we salted, rinsed, and dried our shredded cabbage. This also gave us the texture we wanted—as the salted cabbage sat, moisture was pulled out of it, wilting it to the right crispy texture. For a tangy dressing that clung to the cabbage and didn’t pool at the bottom of the bowl, we supplemented the buttermilk with mayonnaise and sour cream. For finishing touches, we added shredded carrot, which contributed both color and sweetness. The mild flavor of shallot was a welcome addition, and sugar, mustard, and cider vinegar amped up the slaw’s tanginess.
If you are planning to serve the coleslaw immediately, rinse the salted cabbage in a large bowl of ice water, drain it in a colander, pick out any ice cubes, then pat the cabbage dry before dressing.