Behold: Drip-free wine bottle is here!

Anyone who has ever poured wine knows about the drips that run down the side of the bottle. Now, scientists have finally figured out how to fix the age-old problem.

Daniel Perlman, a biophysicist at Brandeis University in the US, studied the flow of liquid across the wine bottle's lip over the course of three years.

By cutting a groove just below the lip, he was able to create a drip-free wine bottle.

There are already products on the market designed to prevent wine spillage, however they require inserting a device into the bottle neck.

Perlman did not want consumers to have to take an additional step after they made their purchase.
 

"I wanted to change the wine bottle itself. I did not want there to be the additional cost or inconvenience of buying an accessory," he said.

Perlman studied slow-motion videos of wine being poured. He observed first that drippage was most extreme when a bottle was full or close to it.

He also saw that a stream of wine tends to curl backwards over the lip and run down the side of the glass bottle because glass is hydrophilic, meaning it attracts water.

Using a diamond-studded tool, Perlman, assisted by engineer Greg Widberg, created a circular groove around the neck of the bottle just beneath the top.

A droplet of wine that would otherwise run down the side of the bottle encounters the groove, but can not traverse it. Instead, it immediately falls off the bottle into the glass along with the rest of the wine.

"When you pour a full or nearly-full bottle of wine, you hold it at a slightly upward angle in relation to the glass," researchers said.

For a drop of wine to make it across the groove, it would have to travel up inside the groove against the force of gravity or have enough momentum to jump from one side of the groove to the other.

After many tests, Perlman found the perfect width - roughly 2 millimetres - and depth, about 1 millimetre, for the groove so that the wine stream can not get past it.