A Massachusetts professor has found his groove in designing a drip-free pour
By Ted McIntyre
Since they started making red wine about 8,000 years ago, people have been staining clothes and tablecloths. The fact that the problem persists all this time later—when global wine production exceeds 28 billion litres—meant that it was high time that someone corrected the problem.
Daniel Perlman to the rescue! A research physicist at Brandeis University, just west of Boston, Perlman started investigating the bottle drippage issue a three years ago. In discovering the solution, Perlman had to find his groove—literally.
“I’ve been a wine drinker for about 50 years now and, having lived in France for about a year, I’m familiar with the problem, particularly with red wines,” says Perlman. “I’ve long thought there might be a solution other than adding appendages to bottles like spigots and the long list of gadgets out there. I thought the solution may lie in reengineering the glass bottle itself, even though the classic Burgundy/Bordeaux wine bottle design has been around a couple hundred years or so.”
Residing in the physics department and “being surrounded by other smart people,” Perlman contemplated what could be done to modify the architecture and change the fluid dynamics and flow of wine from the lip of the bottle in such a way that the wine residue might not drip down the bottle.
“We have great resources here with skilled engineers who can address the challenge of how to create prototypes to simulate what will happen in a real glass bottle.” Perlman continues. “You can’t do that by creating a plastic prototype; you have to modify a glass bottle, so that when you pour wine you can see whether it drips or not. So having a very resourceful and skilled engineer at our disposal (Greg Widberg), we were able to use diamond tools to modify conventional bottles to see what these changes would do.”
Conscious that affecting the conventional cork-insertion method or capsule foil wrapping would entail a massive overhaul to the world’s automation corking systems, Perlman knew that the inside surface could not be touched and that any changes had to be external, and small enough so as not to alter the bottle neck width.
Observing the process in slow-motion video, Perlman noted that drippage was worst when a bottle was full or close to it, meaning when it was actually held at a slightly upward angle. The stream, in that situation, curls backward over the lip and runs down the side “because glass is hydrophilic, meaning it attracts water.”
The solution lay in making it more difficult for those drops to escape. Perlman discovered that a circular groove—optimally 2 mm wide and 1 mm deep—cut just below the lip of the bottle did the trick. A wine drop that would otherwise run down the side of the bottle instead stumbles on the groove and falls down and into the glass. It is unable to traverse the groove because of gravity, since, due to the angle the mostly full bottle is being held, the droplet would momentarily have to defy gravity by flowing upward into the groove before it could continue its path down the bottle.
“Different liquids behave differently,” Perlman notes. “We tested red wine, white wine, higher-alcohol content, other beverages, even water—but our modifications work for virtually any of these liquids.”
The design won’t mean a major expense for manufacturers, Perlman says. “There’s zero cost difference between making these bottles and conventional bottles; the cost is entirely modifying the tooling (and software) to make the bottle neck. In some cases, the mold portion can be interchanged with just the lip portion of the bottle—some have a replaceable neck finish (the upper one to two inches of the bottle).”
The feedback since the March 22 press releasehas been huge. “I’m being bombarded with a number of wineries across the world,” Perlman says. “We’re getting calls from prominent vineyards, particularly California, who are quite interested. From testing the waters, this is not too interesting to lower-end wines—more for medium- to high-priced wines–people who are more fussy.
“We’re currently working with one manufacturer, who would like to remain anonymous at this point,” Perlman adds. “The university is looking forward to licensing possibilities, and there’s at least one patent pending.”
This is not the first time one of Perlman’s creations has gone viral. A noted inventor with more than100 patents to his name (from lab equipment to the first miniaturized home radon detector), Perlman has recently invented a type of flour made from partially baked coffee beans. “It will be surfacing commercially in the next year or two. It’s pretty exciting!”
So is the wine bottle groove for Perlman, whose personal cellar he estimates at an eclectic mix of about 500 bottles.
And what of all those bottles tested over the past three years? “We modified after we drank—or enough time afterward that our judgment wasn’t impaired,” Perlman assures. “Let’s just say that we didn’t waste any wine.”