For some people, coffee is more than just a comforting beverage to sip with breakfast: it’s a magical elixir that grants energy and banishes sleep. But it's unfortunately easy to spill while walking from place to place mug in hand. And according to a new study, this happens because we’ve been holding our coffee mugs the wrong way.
Presumably after spilling his own coffee one too many times, physicist Jiwon Han decided to see if there was a better way to drink his java. Han took it upon himself to test new methods to find a more efficient and stable way to hold a coffee mug, Nick Rose writes for Munchies. He recently published his findings in the open access journal Achievements in the Life Sciences.
“Rarely do we manage to carry coffee around without spilling it once,” Han writes in the study. “In fact, due to the very commonness of the phenomenon, we tend to dismiss questioning it beyond simply exclaiming: ‘Jenkins! You have too much coffee in your cup!’”
As it turns out, it’s not just klutziness that makes it hard to walk around holding a full cup of coffee without spilling everywhere—it’s partly due to the traditional shape of the mug. For starters, Han found that a coffee cup was less likely to spill the taller the mug was compared to the amount of liquid it held. Even so, that’s not exactly an ideal scenario for your standard coffee addict first thing in the morning.
But it's not all about height. When he compared the behavior of coffee served in a wine glass versus a cylindrical cup, Han realized that the shape of the vessel made a big different in how the coffee sloshed about, Lexi Finnigan reports for the Telegraph.
“When a half-full Bordeaux glass is oscillated sideways at 4 Hz, calm waves of wine gently ripple upon the surface,” Han writes in the study. “However, when a cylindrical mug is subject to the same motion, it does not take long for the liquid to splash aggressively against the cup and ultimately spill.”
One of the most important things, however, is the grip. So many hold their coffee by the mug's handle, which throws new forces into the mix. But through extensive testing, Han proposed what he claims is the most efficient way of holding a standard coffee mug to reduce spillage: grasping its rim with a claw-like clasp.
Holding a mug by the top may not make it the easiest to drink from and could result in burns from the steam, but it does keep the mug’s center of gravity relatively stable in a normal walking motion. Han also found a similar stabilizing effect came when he had his subjects walk backwards while holding the mug by the handle.
“Since the magnitude of acceleration in the claw-hand model is significantly smaller, the claw-hand posture is less likely to spill coffee,” Han writes. “Since we are not accustomed to backwards walking, our motion in the walking direction becomes irregular, and our body starts to heavily rely on sideways swinging motion in order to keep balance.”
They may not be the most convenient methods for drinking coffee, but at least they might help keep your clothes free of coffee stains.