On the rocks, neat or with soda, over the last 20 years Scotch has once again become a favorite of American drinkers. From Glenfiddich to Glenlivet to Glenmorangie there has been a Scottish invasion in bars and liquor stores across the country. Pricey single-malts, like the Glens and Macallan, and high-end blends, like Johnnie Walker and Chivas Regal, are extremely popular, but distilleries are now producing ever more expensive bottlings that can cost hundreds or thousands of dollars. How do you choose between the dozens of whiskies filling store shelves? Here’s a primer covering all you need to select the right dram.

Not all whisky is Scotch

As with Champagne or bourbon, there are very strict rules for what is—and what is certainly not—Scotch. The only whiskey that can be called Scotch or single-malt is, in fact, made in Scotland. Anything else is simply whisky (or whiskey if it’s made in the U.S. or Ireland). The spirit must be made in a Scottish distillery and aged in Scotland (in oak barrels which don’t hold more than 700 liters) for at least three years to earn the title. It must be bottled at a minimum of 40 proof. If a Scotch’s label lists an age, the number is reflective of the amount of time the youngest whisky in the bottle has spent in a cask. So, if your bottle is marked as a 12-year-old it may actually contain whisky that’s older.

There are over 90 malt distilleries around Scotland (42 are open to the public), plus additional grain distilleries. Scotch is distilled from malted barley and water, and grain whisky is also used to make blends. Malt whisky is typically distilled twice in bell shaped copper pot stills. Grain whisky is made in tall column stills. (In Ireland whiskey is usually distilled a third time, and is spelled with an ‘e.’ It’s generally not as smoky and often has a honeyed taste.)