The Irish will tell you they invented whiskey-making, and it wasn’t until the Middle Ages that Irish monks brought distilling techniques across the waters to Scotland. Yet that short distance has been far enough that the two whiskeys evolved, over the centuries, into very different styles.

Both Irish whiskey and Scotch whisky are grain-based spirits. Many modern Irish whiskeys are lighter or more accessible in style than their Scottish counterparts, thanks to the differences that have developed in distilling techniques.

Irish whiskey producers generally use a mix of malted and unmalted barley for their mash bill – unlike the Scots, who use all malted barley – and these unmalted grains may enhance earthy, oily notes in the spirit. They generally dry the grains with ovens, instead of the Scots’ traditional peat fires, so with some exceptions Irish whiskeys don’t have the smoky aromas that characterize many scotch whiskies. Finally, Irish whiskeys are typically distilled three times, which is one more go-around than is usual for most scotch whiskies.

These differences are not carved in stone; the Irish Whiskey Act of 1980 outlines only the broad parameters necessary to label a product “Irish” whiskey. Basically, it requires that whiskey be composed of grains (such as barley, wheat, corn, and rye), be distilled to no more than 94.8 percent alcohol, and be aged at least three years in wooden barrels. These guidelines leave producers a lot of leeway to define their styles.

With a whiskey industry that prospered for hundreds of years, Ireland helped establish a taste for whiskey throughout the western world. Legendary producer Bushmills was issued what is now the oldest license to distill spirits in 1608, and within decades Ireland boasted more than 100 distilleries.

But wars, taxes, regulations, business consolidation and, for a time, U.S. prohibition took their toll. Today, the number of Irish distilleries is down to single digits, though each produces a number of different brands and styles.

New worldwide interest in top-shelf spirits has prompted Irish whiskey-makers to explore both new and traditional styles, improve the quality of everyday blended whiskeys, and offer single-malt and small-batch versions for enthusiasts. Increased demand and great quality have inspired producers to open several new distilleries in recent years, and the Irish Whiskey Association estimates more than a dozen new distilleries are in various stages of planning around Ireland.