Everything you always wanted to know about the popular spirit but were too embarrassed to ask.

Whiskey may be Ireland’s national drink, but it is truly a spirit of the world. Travelllers cross the globe, from the islands of Japan to the American south, seeking surprising varieties and sipping old favourites along the way. However, for newcomers to the tipple, it can be hard to get a foot in the door, no matter what country you’re passing through.

To truly become a whiskey expert, you cannot be afraid to ask questions or be intimidated by seasoned whiskey samplers. Ignore the folks who approach whiskey with a pretentious, know-it-all attitude. True whiskey lovers always want to learn more and share their knowledge with others. In this spirit, we'll help you learn about the whiskeys of the world by tackling some of the most frequently asked questions out there.

What is the difference between whiskey, scotch and bourbon?
Even self-proclaimed connoisseurs sometimes provide incorrect answers to this common question. It's a trick question, really, because whiskey is the overarching category of spirits that scotch and bourbon fall under. Both scotch and bourbon get their names from places – scotch from Scotland and bourbon from Bourbon County, Kentucky – but true scotch is made only in Scotland, while bourbon can be made in parts of America outside of Kentucky.

"Whiskey" can refer to any kind of whiskey – Irish, Japanese, Canadian, American, scotch and bourbon being the main types. Aficionados and Irish drinkers may refer to Irish whiskey as simply "whiskey," whereas they might specify location when talking about other types.

Wait, is it "whiskey" or "whisky"?
It's both. "Whiskey" is the Irish spelling (used in Ireland and the US), while "whisky" is the Scotch spelling (used in Scotland, Canada and Japan). The New York Times actually changed its style guide when bombarded with scotch fans calling for the "whisky" spelling in the naming of Scottish varieties, but since this column is running during Ireland Week, we're keeping the "e" in. Whichever spelling, the origin of the word goes back to both Ireland and Scotland. Uisge beatha or usquebaugh is Gaelic for "water of life". It was translated from the Latin aqua vitae, used to describe spirits.

Where did whiskey originate?
Both Ireland and Scotland claim to have given birth to whiskey. But, as food writer Kate Hopkins notes in her book 99 Drams of Whiskey, neither country has definitive proof. "Ask an academic," she writes, "...and he or she is likely to shrug and mumble, 'Hell if I know. That part of the world wasn't too keen on keeping records of who was doing what.'"

The making of liquor dates back to at least 800 AD when Arab chemist Abu Musa Jabir ibn Hayyan was carrying out distillation, the purifying of a beverage made via fermentation (i.e. beer, wine or hard cider). Wine was already being distilled around the world when physicians tried distilling beer in either Ireland or Scotland (or both), according to the late English whiskey writer Michael Jackson. In his book Whiskey: The Definitive World Guide, he explains that a family of physicians, the MacVeys (a.k.a. the Beatons), translated medical texts from the Arab world whose secrets of distillation resulted in the first whiskey creations. As doctors, the MacVeys/Beatons served both Ireland and Scotland, which is why whiskey's exact origins remain murky. Let's just call it a tie.

How are the different kinds of whiskeys made?
Generally, whiskey is made by (1) crushing grains (barley, corn, rye, wheat, etc.) to create the grist, (2) adding water to create the mash (3) boiling this mixture and then allowing it to cool, (4) adding yeast, which carries out fermentation by eating the sugars to create alcohol, (5) draining the resulting liquid, which is now beer, and then distilling using a still and (6) aging the resulting liquor in wooden barrels.

Here's how the different varieties are made:

Scotch is made from water and malted barley (ie. barley that's been steeped in water to trigger germination), distilled to less than 94.8% alcohol, aged for at least three years in oak barrels that can hold no more than 700 liters, and bottled at no less than 40% alcohol. No additives are allowed except for water and caramel colouring. By law, it can only be called scotch if it follows this process and is made in Scotland.

"Single malt" scotch is made from malted barley in a single distillery while "single grain" is made from malted barley and other grains in a single distillery. "Blended" scotch is a mix of whiskys/eys from multiple distilleries.

Irish whiskey is distilled to less than 94.8% alcohol and aged for at least three years in wooden barrels. By law, whiskey can only be called Irish whiskey if it follows this process and is made in Ireland.

Bourbon is made from a mash of at least 51% corn, distilled to 80% alcohol, combined with water to get the alcohol content down to 62.5%, entered into an unused charred oak barrel, aged in that barrel and then bottled at no less than 40% alcohol. By law, whiskey can only be called bourbon if it is made by this process and in the United States.  

Tennessee whiskey is bourbon made in the state of Tennessee and filtered through sugar-maple charcoal. Other American whiskey includes versions made from rye, corn, barley and other grains. Blended American whiskey is a mix of 20% American whiskey and 80% neutral spirit.

How do I drink whiskey?
There's a vocabulary associated with spirits sipping that will come in handy when ordering at the bar. Certain words describe how your bartender will serve your liquor. Ask for your whiskey neat if you want it poured in your glass unadorned, at room temperature. On the rocks, conversely, means you want it poured over ice in your glass. Straight up usually means the same as "neat", but its usage can cause confusion, as American mixologist Jeffrey Morgenthaler has explained, because there's also the term up, which usually means chilled and served in a cocktail glass. You can also order your whiskey with a splash of water or water back, that is, a glass of water on the side. And, of course, there's no shame in simply spelling out in plain language what you'd like when ordering. Whiskey drinking isn't about memorization; it's about enjoying yourself.

We recommend enjoying whiskey with a little bit of water added. (And with a little more water added when it comes to high alcohol content barrel proof, aka cask strength, whiskeys, which are bottled without any water added.) Some amount of dilution helps your nose and tongue smell and taste more of the flavours in your whiskey because it counteracts the alcohol's numbing of your senses. This is what whiskey tasters mean when they say that water helps "open up" the flavours.

When learning how to taste whiskey, keep in mind appearance, aroma (of first the straight whiskey and then the diluted whiskey), mouth-feel and flavour. For a quick tasting tutorial, famed whiskey taster Charles MacLean, author of Scotch Whisky: A Liquid History, demonstrates his approach for Single Malt TV.

For a slightly more in-depth explanation of professional tasting, consultant editor Michael Jackson, an expert modest enough to recognize that his word on the subject was far from Gospel, shared his approach in Whisky Magazine.

Which whiskeys should I try?
For a final bit of direction, we've come up with suggestions for delicious varieties to taste. The next time you're at a whiskey bar – in Dublin, Speyside, Kentucky or anywhere else this spirit is dearly loved – see if they have one of these on the menu.

  • Bushmills 12 Year Old: an Irish whiskey with hints of sherry, fruit and nuts
  • Connemara Single Malt: a peaty whiskey, sweet, with hints of vanilla, from Ireland's only independent distillery, Cooley
  • Dalwhinnie: scotch infused with an aroma of heather
  • Ezra B Single Barrel: aged for 12 years, this bourbon is complex and tastes of spices and honey
  • Glenfarclas 12 Year Old: a single malt scotch from Speyside that's nutty and peaty with caramel notes
  • Talisker: peaty scotch from the Isle of Skye
  • Willett 8 Year Old: a rare release bourbon from Kentucky, its barrel proof bite gives way to deep, smoky, molasses flavours

By now you must be good and thirsty. So go on and raise your glass. Sláinte!

CORRECTION: An earlier version of this story identified Talisker as an Irish whiskey. It is a scotch.

Travelwise is a BBC Travel column that goes behind the travel stories to answer common questions, satisfy uncommon curiosities and uncover some of the mystery surrounding travel. If you have a burning travel question, contact Travelwise.