Waxy and floury potatoes
Floury potatoes (russet, Idaho) are high in starch and fall apart when boiled, so they mash fluffy and fry crisp. Waxy potatoes (new, red, fingerling) hold their shape, which suits salads and boiling.
Mash gently
A hand masher or ricer on hot potatoes keeps mash fluffy. A blender, food processor or hard beating tears open so many starch granules that the mash turns gluey. Stop once the lumps are gone.
Test yourself
Questions from the interactive lesson, with the answer and the why.
You're mashing potatoes for six and have russets and red-skinned potatoes. Which gives the lighter mash?
Russets, which are high in starch. Starchy flesh breaks into dry, fluffy crumbs that absorb butter and milk.
True or false: For potato salad with neat cubes after boiling, waxy potatoes beat russets.
True. Waxy potatoes have less starch and more water, so their cells stay stuck together after boiling.
What went wrong? You puree hot potatoes in a food processor. The result is a thick, sticky paste.
The blades tore the starch into glue. Fast blades shred starch granules and release sticky starch. Use a ricer or masher.
Fill the blank: Potatoes go into ___ salted water, so the center cooks before the outside turns to mush.
Potatoes go into cold salted water, so the center cooks before the outside turns to mush. Heat reaches the center as the water warms, so the outside doesn't turn mushy first.
Why do roast potatoes come out crunchier if you parboil them and shake them in the pot first?
Rough, starchy edges fry crisp in hot oil. Shaking roughs up the surface into a starch paste that turns crunchy in hot fat.
