Inside each of the potatoes’ cells are hundreds of granules... Inside those granules is a clear, thick paste of starch that the plant manufactured during its photosynthesis days as nourishment for its future generations.Additional details (and four additional "food flubs" re frozen turkey, turkey skin, gravy, and cranberry sauce) at the Washington Post.
Break open too many of those granules, letting too much of the starch paste leak out, and you’ll end up with pasty mashed potatoes. So unless you want to use the result for affixing wallpaper, don’t use a food processor or a blender. Their high-powered blades can reduce the potatoes to a puree, which is great for juicy, non-starchy fruits and vegetables. But by the time a potato is squished to that degree, most of its starch granules have been torn open, spilling their gluey contents.
Mixers can do both mixing and beating/aerating. However, beating potatoes in a mixer in an attempt to make them fluffy is almost as bad as using a blender. It’s okay to use a mixer on very low speed to distribute additives such as butter and milk. But beating them too vigorously will break down their starch granules into glue just as a blender does.
btw, TYWKIWDBI will be in diapause for several days while I take an extended Thanksgiving break.