Centrifugal Buttermilk-Extractor Churn: A Spinning Drum That Throws the Buttermilk Out

"After the butter has come or is separated from the buttermilk, we pull up the bolt R, to open the doors P, of the openings T, and continuing the revolution of the churn A, we throw off the buttermilk by the openings T, from the churn A, into the dripping-pan J, to be discharged at the aperture K, while the butter is retained in the churn A."

Print the arms with their collar and reach (/uploads/blueprints/centrifugal-buttermilk-extractor-churn-arms.stl), three projections (/uploads/blueprints/centrifugal-buttermilk-extractor-churn-projection.stl), two doors (/uploads/blueprints/centrifugal-buttermilk-extractor-churn-door.stl), the drum hub (/uploads/blueprints/centrifugal-buttermilk-extractor-churn-drum-hub.stl) and the crank arm (/uploads/blueprints/centrifugal-buttermilk-extractor-churn-crank-arm.stl). Print in PLA at 0.2 mm layers, 30 % infill, 4 walls; wash before first use.

Take a round food-safe container about 190 mm across. Cut two openings 30 × 60 mm low in its side and hinge a door over each on a stainless pin, with a turn-button to hold it shut. Glue the three projections inside, standing in from the wall. Glue the drum hub under its floor and screw it to a lazy Susan on a board, so the drum turns freely. Stand a roasting pan under and round it to catch the buttermilk.

Build a pine frame over the drum. Hang the arms on a 10 mm dowel from the frame's top bar, reaching into the drum between the projections, with a hook from the frame into the reach's hole to hold them still. Glue the crank arm to a dowel handle fixed upright on the drum's rim, so you turn the drum by hand.

Let the heavy cream stand until it reaches about 15 °C, checked with the thermometer. Pour in 1.5 litres, doors shut. Turn the drum briskly while the arms stay still; time until the butter comes. Then open the doors and keep turning, so the buttermilk is thrown into the pan while the butter stays. Add cold water, turn again and spin it out until it runs clear; add a pinch of salt and turn to work it in. Weigh the butter.

**Osbert B. Loomis** of Windsor, Hartford County, Connecticut, received US 7,247, dated 2 April 1850, signed 29 October 1849. His churn was geared so that, by moving a hook and a pin, the drum, the arms or both could turn; it could work "upon a horizontal or vertical axis, or an axis at any angle whatsoever." He also described cleansing rancid butter with lime water; this build does not, and nothing should be added to butter unless you know it is safe. He claimed the devices of gearing by which the motions of churn box and dasher are changed so that while one is stationary the other rotates and vice versa. **Honest limits.** We turn the drum by hand on a lazy Susan instead of his gearing, so it spins slower; a container and printed parts stand in for his. FDM prints hold food in their layer lines, so wash well and replace when worn. Your times and weights are the result.