Place the potatoes in a large pot and add enough water to cover them by about 1 1/2 inches. Stir in salt, using about 1 teaspoon for every quart of water.

Set the pot over high heat and bring to a boil, then lower the heat to a gentle simmer. Boiling too vigorously can make the potatoes bump into each other and crack apart. Cook for 15 to 20 minutes, or until a fork slides into a potato with little resistance.

While the potatoes cook, prepare an ice bath by filling a medium bowl with ice cubes and cold water.

Drain the cooked potatoes and immediately transfer them to the ice bath. Once they are cool enough to handle but still warm in the center, remove them and cut into bite-sized chunks. Place the chunks in a large bowl, sprinkle with the vinegar, and season lightly with salt.

In a small bowl, whisk together the mayonnaise, sour cream, and mustard until smooth and creamy.

Add the dressing, celery, pickles, parsley, dill, and chives to the potatoes. Fold everything together gently with a spatula, being careful not to break up the potatoes too much.

Taste the salad and adjust seasoning with salt and black pepper as needed. If you have time, cover and refrigerate for at least 30 minutes before serving so the flavors meld.