Brad Thomas Parsons, the author of essential bartender's manual Bitters: A Spirited History of a Classical Drink' writes "Gone are the days when a lonely bottle of Angostura bitters held court behind the bar." What was once an ingredient used only in a handful of classics is now an integral part of any good bartender's arsenal. They give a much needed punch of flavour without occupying much space, or diluting the cocktail. It also allows a bartender to have an array of tastes at his fingertips without having to stock a fridge full of expensive perishables. And now Toronto company Bar40 Bitters is looking to take the ingredient to the next level.

Bitters are an infusion of herbs, spices, roots, flowers and other flavourings steeped in high-proof alcohol, along with an added bittering agent such as wormwood, citrus peels or gentian. After about a month of steeping, the flavours start to shine through brilliantly. The sky's the limit on what flavours or flavour combinations can be achieved: Peppercorn bacon, smoke and coffee, curry, and Jamaican jerk are just the tip of the bitters iceberg. No flavour is too bold or too intricate to create.

There's been much attention paid to the emerging bitters scene here in Toronto, with every serious cocktail bar having at least one or two mysterious jars behind the bar including a house recipe or two, but for the home enthusiast, the prospect of tracking down all sorts of rare barks and spices, then sacrificing a whole bottle of booze, before waiting over a month, seems like a big undertaking. Thankfully, there's a huge range available at places throughout the city like BYOB where home bartenders can get their hands on materials with which to experiment. Until recently, most of these were imported (at a hefty cost) from the States and the UK, but it seems that a few locals are now trying to make their own versions available to us amateurs.

Bar40 Bitters advocates a more scientific approach in developing bitters for cocktail use. They've based a range of four varieties on the understanding that the tongue allows one to distinguish five specific flavour profiles: bitter, salt, sour, sweet and savoury (or umami). Ideally, any perfect taste experience should combine the five in some fashion. Owner Jamie Beurklian and business partner Robin have aimed to produce a set that complemented cocktails without dominating them.

By allowing a budding mixologist to augment a drink with a touch of saltiness or a gentle savoury note, the four bitters they've released, used either individually or in tandem, tweak the balance of a drink to bring it closer to that ideal taste experience. Should you be interested in finding ways to better balance your drinks, but don't want to shell out on obscure flavours that might only have one or two possible applications, then this might be the best starting point.

You can pick up Bar40 bitters at BYOB and The Crafty Bartender for $19 a bottle at their online store or in the next drink at your favourite bar. Plans are also afoot for an olfactory set (similar to those really expensive sommelier kits you see in wine stores). Jamie also has a mystery third set in the works as well as plans to bring his sensory approach to other bartending staples like vermouth and amaro.