We've been living through a cocktail renaissance. It's now standard to find house-made bitters and speciality sodas behind any bar. Recent years have seen drinks with seaweed, smoke and cold-brew coffee all make an appearance at the Diageo Reserve World Class bartending competition.

In search of the perfect drink, bartenders have deconstructed, analysed and refined every element in your glass, ice included.

“If your bartender is going to spend lots of time, effort and money procuring the finest ingredients for your cocktail, it is major oversight to stop when it comes to the ice,” says Charles Joly, who took home the title of world’s best bartender at last year’s World Class competition.

During his time overseeing the bar at Chicago icon The Aviary, Joly had two ‘ice chefs’ on staff, carefully crafting more than 25 different shapes, sizes and flavours of ice. The Aviary's Old Fashioned in the Rocks has become the stuff of legends for bar afficiandos – served up in a hollow sphere of ice, the customer cracks the shell to release and chill their drink.

While ice is a seemingly innocuous ingredient, Joly explains it's the common thread in almost every cocktail recipe in the world.

“After a cocktail is shaken, it may have as much dilution added by this ice as the base ingredient, say upwards of 40-50ml,” Joly says. “All of the sudden, it becomes a major component and one not to be overlooked.”

To control dilution and maintain the drink’s quality of flavour, bartenders are increasingly turning to expertly crafted ice; crystal clear, incredibly dense blocks that melt more slowly. There are now more than 20 specialty producers in the US, supplying top bars for around $1 a cube.

Australia recently got its first boutique hand cut ice company, Navy Strength Ice Co., owned by Michael Madrusan of Melbourne bar The Everleigh.

Navy Strength uses the gold standard of ice makers, a Clinebell, traditionally the go-to for ice sculptors. The machine slowly freezes highly filtered water from below, circulating to ensure no air is trapped inside, which would make the final cube cloudy. It takes up to three days to freeze a 150kg block.

By hand cutting the blocks, bartenders have the freedom to sculpt the ice to suit each drink - from huge cubes to chipped pebbles for a mint julep or a perfect sphere, long the standard for bars in Japan.

“Any bar worth it's salt is already considering the impact ice makes on their drinks,” says Dave Kerr, owner of The Beaufort in Carlton. “Navy Strength defies ability and logic, its perfectly square and completely see through.”

At The Beaufort, Kerr hand cuts ice for drinks on the rocks, and says customers don't need to understand the science of ice to know why artisanal ice is better: they'll taste the difference in their drink.

“The magic happens when you can combine a welcoming, non-pretentious atmosphere with thoughtful, expertly crafted cocktails,” says Joly.