The force required to operate the plunger on a French press

Wadsworth, Fabian B.; Vossen, Caron E.J.; Heap, Michael J.; Kushnir, Alexandra; Farquharson, Jamie I.; Schmid, Diana; Dingwell, Donald B.; Belohlavek, Lukas; Huebsch, Mila; Carbillet, Lucille; Kendrick, Jackie E.

doi:10.1119/10.0004224

The force required to operate the plunger on a French press

Wadsworth, Fabian B.; Vossen, Caron E.J.; Heap, Michael J.; Kushnir, Alexandra; Farquharson, Jamie I.; Schmid, Diana; Dingwell, Donald B.; Belohlavek, Lukas; Huebsch, Mila; Carbillet, Lucille; Kendrick, Jackie E.

Authors

Dr Fabian Wadsworth fabian.b.wadsworth@durham.ac.uk
Associate Professor

Caron E.J. Vossen

Michael J. Heap

Alexandra Kushnir

Jamie I. Farquharson

Diana Schmid

Donald B. Dingwell

Lukas Belohlavek

Mila Huebsch

Lucille Carbillet

Jackie E. Kendrick

Abstract

The French press is a popular device for brewing coffee, comprising a cylindrical beaker—or “jug”—fitted with a lid and plunger with a fine wire mesh filter. The plunger is used to drive the solid coffee particles to the bottom of the jug, separating these grounds from hot liquid above. When using the French press in this way, a growing permeable pack of ground coffee is pushed through hot water by applying force to the plunger. We use a combination of kitchen-based and laboratory experiments to determine the force required to push on the plunger as a function of the speed of the plunger and the mass of coffee used. We calculate that for the recommended preparation method, the maximum force is 32 N to complete the pressing action in 50 s. We propose that home coffee preparation provides a fun, low-cost, and relatable learning opportunity for students and for those who are interested in coffee science.

Citation

Wadsworth, F. B., Vossen, C. E., Heap, M. J., Kushnir, A., Farquharson, J. I., Schmid, D., …Kendrick, J. E. (2021). The force required to operate the plunger on a French press. American Journal of Physics, 89, Article 769. https://doi.org/10.1119/10.0004224

Journal Article Type	Article
Acceptance Date	Mar 19, 2021
Online Publication Date	Jul 20, 2021
Publication Date	2021
Deposit Date	Dec 16, 2021
Publicly Available Date	Dec 16, 2021
Journal	American Journal of Physics
Print ISSN	0002-9505
Publisher	American Association of Physics Teachers
Peer Reviewed	Peer Reviewed
Volume	89
Article Number	769
DOI	https://doi.org/10.1119/10.0004224

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Copyright Statement
© 2021 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Wadsworth, Fabian B. , Vossen, Caron E. J. Heap, Michael J., Kushnir, Alexandra Farquharson, Jamie I. Schmid, Diana, Dingwell, Donald B. Belohlavek, Lukas Huebsch, Mila, Carbillet, Lucille & Kendrick, Jackie E. (2021). The force required to operate the plunger on a French press. American Journal of Physics 89: 769 and may be found at https://doi.org/10.1119/10.0004224