Two centuries ago, every East Coast community had an ice house and an army of icemen delivering 50-pound blocks weekly. Before electrification, ice was essential to refrigeration and all but unknown in tropical zones.

Today, ice is so commonplace we give it hardly a thought. Take a  cocktail, a Manhattan, a Rob Roy, or a humble 7 n’ 7 on the rocks. The whiskey matters, be it Glen Breton Rare or Slàínte Mhaít Single Malt Whiskey. But, how much thought goes into the rocks, the ice cubes?

At the dawn of the 19th century, Frederic Tudor of Massachusetts pioneered the shipping of ice to southern climes, becoming fabulously wealthy and earning the moniker the “Ice King.” He also ignited an ice cream craze in Cuba that persists. “Helado por el pueblo” (ice cream for the people) was one of Castro’s revolutionary slogans, and ice cream vendors still patrol the streets of Havana.

In 1821, Frederic dispatched his youngest brother to New Orleans to introduce ice to the U.S. south. Harry wowed bartenders there with the “Gin Smash” (gin chilled and shaken over ice, poured over fresh mint and syrup), forebearer of the bourbon-based mint julep. Cocktail connoisseurs greeted the chilled concoction with delight. Soon, daiquiris, highballs, martinis, and a host of chilled cocktails were all the rage.

Ice author Amy Brady writes, “Harry and the ice he sold had changed the city, and cocktail culture, forever.” Sommelier and P.E.I.’s Red Island Hospitality general manager Ameya Sharma summarizes the importance and nature of ice’s dual role in a cocktail: ice chills a cocktail while diluting it. The proper ice for a particular cocktail offers the correct balance of these two effects and that, in turn, is determined by the ice’s size and shape. Ice is as important to a craft cocktail as the three fundamentals: the base (liquor/liqueur), the modifiers (mixes/additives), and the garnish.

Ice in a cocktail can even have an aesthetic impact. P.E.I. sommelier Lesley Quinn, fondly recalls an “Espresso Negroni that featured a gorgeous cube that came complete with the (Vancouver) club’s monogram stamped into it.” Alternately, ice can be coloured. Indeed, one can even have a cocktail in ice, courtesy of specialty shot glasses made of ice.

And all of this brings us to Garth Brown, award-winning restaurateur and culinary management instructor at Nova Scotia Community College. He is willing to “argue that ice is the most important component of a cocktail.” It has to be clear, hard, and free of impurities. This requires filtered water and directional freezing.

Directional freezing is the key to quality ice. Left to its own devices, in an ice cube tray the cubes freeze from the outside in, trapping air bubbles and impurities in the cube. The former make the ice appear cloudy, the later can alter a cocktail’s taste, texture, and mouth feel. Directional freezing involves freezing ice from the top down, pushing impurities and air bubbles down. The result, with the dirty ice on the bottom cut off, is pure, clear, hard ice, ideal for cocktails. To this end, the NSCC deploys a variety of ice machines that make blocks and cubes of assorted sizes.

At The Clever Barkeep in Dartmouth, N.S., co-founder and mixologist Jeff Van Horne admits to “being passionate about ice.” He has two ice machines producing cubes and pebble ice, and also make blocks that are cut into appropriate sizes and shapes. He describes cutting the blocks as “mesmerizing,” and great entertainment. Like Brown he sees ice as fundamental to a cocktail, as important as the base alcohol.

Presiding over a beautiful bar fashioned from the St. John the Baptist Church’s organ and 10 pews, at Kakutera (Japanese for cocktail lounge), Saint John, N.B., mixologist Eric Scouten considers ice so important that he also makes his own. The blocks of ice are then shaved, chipped, crushed or cubed to appropriately complete his seasonal craft cocktails that feature local, and often foraged, ingredients. Excellent ice, according to Scouten, requires “honing fundamentals and mastering techniques.” The key, as always, is directional freezing.

Ice is both art and serious business. Pebble ice in a shaker will chill quickly while a rolling shake with cubed ice will knock the corners off, creating flakesA Collins glass calls for a tall cylinder of ice while an old fashioned calls for large rocks that chill without diluting and “calm the heat,” according to Brown. In any craft cocktail the ice should be pure, clear and hard. Its size and shape must pair with the ingredients, balancing chilling and diluting.

The final word belongs to P.E.I. sommelier Sharma, “Good ice can heal a breaking drink and bad ice can break a healing one.”

 Better Ice at Home

• Use any recommended method, but always directional freeze – from the top down. You can find lots of great tips for directional freezing on line, or talk to your favourite mixologist.
• Bag your ice so it doesn’t pick up odours.
• Don’t scrimp on ice. Fill the chilled shaker with ice, chill the glass, and use the appropriately sized and shaped ice.
• Freeze a block and cube it in front of your guests. It’s great party entertainment, according to Jeff Van Horne.