Start with cut, peeled russets in salted water. They will invariably be done way before something else in your meal is done, so once they are done, drain them and let the chunks sit, covered, in the pan until you are ready to mash them. They will stay hot for a long time like this, and the bonus effect is they will absorb any remaining surface water while sitting there. You know you’re in good shape when they look a little dry when you take the lid off.
Put into bowl and mix with you mixer until partially mashed potatoes and then add melted butter first Don’t waste the heat in the potatoes on cold butter. Fold in something like 2 Tbsp real butter for every potato (oh, it’s the holidays – just do it).
After the butter, sprinkle liberally with salt and then add (this is the secret) a pinch of sugar. (about a teaspoon). NEVER add milk orhalf and half until you have whipped your potatoes smooth making sure to get the lumps out. If you add the milk or half and half before then you will never be able to get the lumps out.) Mix until smooth and then add HOT half-and-half — I use about a 1/4 cup for every three medium russets. Just do not add too much liquid at first in case the potatoes retained too much liquid. After the holidays you can add whole milk for calorie purposes. The reason for doing this in this order is the butter coats the starch granules first and keeps it from turning into glue. Taste and adjust the salt and pepper , add more half and half if needed.
If you now have to take the mashed potatoes to Aunt Mildred’s house, it’s a good idea to check them to see if they have soaked up too much liquid. If they look a little dry add a good chunk of sweet butter and stir in before everyone sits down to the table. Yum!!
Another secret is to add 1/2 cream cheese and 1/2 butter. Then use sour cream in place of half and half, using just enough to be able to finish off with heavy whipped cream. The cream cheese and sour cream will stabilize the potatoes and keep them from clumping and making them very easy to re-heat. . Of course my great-grandmother and grandmother would have never ever considered the last option because they had those taters on the table immediately! No time for clumping!!