Speeding Up and Slowing Down in the Kitchen

Saturday Cooking at the Haddads'

Noor Haddad helps make dinner every Saturday. Her family's salad spinner has a basket inside a bowl and a pump handle on the lid. Each push on the handle turns gears that spin the basket faster. A button on the lid presses a small rubber brake pad against the basket to stop it.

Noor wanted to measure what happens. She put a sticker on the rim of the empty basket and filmed it in slow motion with a phone, so she could count rotations per second after each push of the handle. Then she pumped 4 times and timed how long the empty basket took to stop, once letting it coast and once pressing the brake. She repeated both stopping tests three times and the results were within 2 seconds of each other, so she recorded the averages. While it coasted, a scrap of paper inside the bowl fluttered in the moving air. After she braked the basket ten times in a row, the brake pad felt slightly warm.

Later her dad mixed bread dough with a stand mixer and a dough hook. Noor split the fresh dough into two equal balls. One was kneaded by the mixer, and the other sat in a bowl beside it. The kitchen stayed at 22 °C. Every 4 minutes she checked both balls with a food thermometer. Kneading stretches and folds the dough again and again. Her dad said bakers watch dough temperature closely, because dough that gets too warm can rise too fast.