Why do teapots dribble

What's Going On? If theory is not your cup of tea, here are some concrete ways to avoid the teapot effect. Pour Sport Pour quickly, so the momentum of the tea can overcome other forces acting on it. Keep Sharp A thin, sharp-edged lower lip makes it more difficult for the fluid to flow around the lip of the spout.

Narrow Spout Narrow spouts seem to work better. Keep It Up If the lower lip of the spout heads upward in the pouring position, this makes extra work for the fluid to get around the edge. Superhydrophobia Superhydrophobic materials don't just dislike water, they push it away. If you have any explanations or observations on the Teapot Effect, short and stout or otherwise, pour them out in the comments.

We believe that now, more than ever, the world needs people who care about science. Help us fund the future and next generation of problem solvers, wonder seekers, world changers and nerds. Donate Now. The team, led by Cyril Duez, say the use of "superhydrophobic surfaces" — essentially water-repelling linings — on the inside of the spout can avoid dripping and "thus beat the 'teapot effect'". The scientists are not the first to bend their minds towards the problem.

This year the retailer Debenhams claimed to have designed a dribble-free teapot with a "multi-faceted solution" that involved a larger spout, "tea bag baffle" and redesigned lid. Her solution was a groove under the spout. The latest intensive research appears to be the first to tackle the dribbling problem from an explicitly scientific perspective. The Lyon team's verdict: marry a superhydrophobic surface with the more traditional method of using a sharp edge at the end of the spout, creating a drip- and hassle-free pot.

What about other brew-time dilemmas? The previously identified factors all determine the strength of this hydro-capillary effect but Mr Duez has come up with solutions. The first is to make the lip as thin as possible. That is why teapots with spouts made from thin metal are less likely to dribble.

The second is to coat the lip with the latest generation of superhydrophobic materials, which strongly repel water. Mr Duez and his team show how this stops dribbling. The technique backs up one traditional way of stopping the dribble - putting butter on the spout. The findings demonstrated in the paper Beating the teapot effect were published in arXiv, the online science journal. Scientists spout new theories about teapot-dribble mystery.