The Spiral Dough Mixer: Turn It Over, Press It Against the End

"My invention relates to improvements in dough-mixers, whereby a construction is provided that is peculiarly well adapted for mixing dough successfully by movements that involve kneading and pressing the dough, and is so constructed that the parts can be readily removed, cleaned, and replaced properly in the mixer". "It will be understood that when used dough is placed in the receptacle, and by the rotation of the spiral mixer the dough will be turned over and kneaded primarily by the medial round smooth portion 2 and by it and the blade-like parts 3 will be moved toward the end of the receptacle and will be pressed and kneaded against the end of the receptacle until the mass there falls back into the central portion of the receptacle, when the process will be again repeated until the dough shall have been thoroughly and sufficiently mixed."

Wrap stiff stainless steel wire two full turns round a jar a little narrower than the food container. Stretch the coil until it is as long as the container, less 4 cm. At each end, bend the wire in to the centre line as an arm, then out along the centre line as a short axle. Leave one axle long and bend it into a crank. Hammer the last quarter-turn at each end flat. Drill a hole in the middle of each end of the container, halfway up, for the axles. Spring the spiral in and check it turns without scraping. Put in 500 g of bread flour, 7 g of instant yeast, 10 g of salt and 330 mL of water. Crank steadily and count the turns for ten minutes. Stretch a small piece: when it thins to a see-through sheet without tearing, it is kneaded. Compare with the same dough kneaded by hand.

**John Koelner** of Louisville, Kentucky, filed US 722,112 on 9 April 1902; it is dated 3 March 1903. His crank turned the spiral through a pinion and a cog-wheel on one hub, and thumb-screws let the spiral be taken out for cleaning. **Honest limits.** The notebook treats the dough as moving a fixed share of the pitch per turn; real dough sticks, stretches and slips. Sizes, speeds and slip are examples. Your turn count and the stretch test are the measurement.