How long to boil potatoes for potato salad

Because a salad potato has to survive handling that mash never faces. Waxy potatoes hold more moisture and less starch, and their cells stay bonded through cooking, so a slice stays a slice through stirring and a night in the fridge. Floury potatoes are bred for the cells to separate, which is exactly what you want under a masher and exactly what you do not want in a bowl. Use floury ones and you get potato paste with dressing in it.

Warm, at least for the first layer. A hot potato is still open and drinks up vinegar, stock or oil, and a cold one barely takes any. The German approach leans on this: hot stock and vinegar go on while the slices are still steaming, then oil, then the rest once they have cooled. If your recipe uses mayonnaise, dress with the vinegar warm and stir the mayonnaise in only after they have come down to room temperature, or it will split.

Yes, and there is a real advantage to it. Cooled potatoes firm up as the starch recrystallises, so slices hold together better on day two than on day one. Cool them quickly, get them into the fridge inside two hours, and use them within three days. Leaving a pan of cooked potatoes on the counter overnight is a genuine food safety problem, not fussiness.

Whole for the cleanest result. The skin keeps the water out and the flesh intact, so the slices you cut afterwards have square edges and no ragged faces. Cubes are quicker and soak up more dressing, at the cost of some broken corners. Either way, salt the water properly, because unsalted salad potatoes taste flat no matter how good the dressing is.