[Christien]

There are many reasons why one is "harsher" than another, but you can boil most of it down to quality. A better whisky will be (or at least should be) smoother.

First off, you're drinking bourbon, which is variant of whisky, like scotch or rye. It's basically the same stuff, but the flavour is significantly different. Our Canadian rye is closer to a blended scotch or whisky, whereas bourbon is quite different. It's sweeter, and has a slight fruit to it that a rye whisky or blended scotch doesn't have. It's not necessarily better or worse, just personal preference. I love them both, but in much different ways.

Try some blended scotches next - you'll probably find them a little more harsh, but it's a different flavour. Then step up to a single malt - that's where you're really going to find the ultimate smoothness, but with that comes price.

Whiskies are almost as complicated and varied as red wines, so there's a lot involved in answering your question properly. The best way to find out is also the most fun way - experimentation.