It's surprising how many people thinks it's cool to have a bubble or lens (meniscus) form at the very top of a jigger pour prior to serving alcohol into a glass.
Sorry to be the bringer of bad news: the bubble creates BIG trouble... the Why, What and Cost see below.
A bubble or lens for most bars is fact of life affecting almost every design of jigger on the planet!
Liquor control experts such as Barmetrix acknowledge that the bubble can add 3-5mL or 1/10-1/6 Oz on every 30 mL/1 Oz served!
If you own or manage a bar, the added cost of the bubble can cripple business!
Flip this around to the other side of the counter: imagine a guest who enjoys a well-balanced cocktail experience, if their drink has been over-portioned the drink could potentially taste too strong, too sweet, too sour or just plain weird.
Drinking and driving? Get pulled over and breath tested… then good luck finding an understanding "Your Honour!" Could end up getting a very different type of serve, with rather unfortunate “benefits!”
Why It Happens
All jiggers and shot glasses except one, are round! Once a pour reaches the top edges of a jigger or shot glass, nature takes over, exerting surface tension, pushing liquid inwards and towards the midpoint of the jigger, thereby forming a bubble.
Once the surface tension reaches a tipping point, the bubble will break, particularly when energy or motion is exerted by a bartender... the result, alcohol cascading down the sides of a jigger, to be seen on a counter top or floor!
To some a fraction of an Oz or those extra pesky mL's don't seem much but during a brisk night's trade the bubble can increase the cost of a fairly basic speed rail drink by $0.05-$0.15 cents per shot….potentially more if serving back bar booze. Ouchhhh if you’re making lots of Long Island Ice teas or serving expensive cocktails!
Thankfully to stop being Bubble Dumb, the answer is simple and CHEAP... it’s just a question of looking for the right tool to do the job, something like the ProJig™ or ProBarJig™; specifically designed to Flat Pour (no bubble) See here.