Hi, this is my first post on these forums.

A while ago when I was drinking some scotch with my brother, he shook the bottle before serving it, saying that certain chemicals in the whiskey settle at the bottom.

Some time later, I met a guy at a friend's house who had brought a bottle of bourbon with him.  He seemed to know a good deal about whiskey, so I asked him about shaking the bottle to get an even mix.  He said the stuff that settles at the bottom is stuff you'd rather not have in the whiskey and makes it taste worse.  He said you're not supposed to shake it, but you are supposed to store the bottle sideways, not upright.

So, what's the proper thing to do to get the best-tasting whiskey? 

Hi, and welcome to the forum

Storage of the bottles first: Any bottle with high alcohol content such as whisk(e)y, bourbon, rye, rum, vodka etc should be stored upright, if the bottle is closed with cork. The reason is that the alcohol will detoriate the cork if in direct contact. If the bottle is closed with a screw capsule, then it doesn't really matter. This is different of storing wine, where it should be stored sideways, so the cork won't dry out. Please note, that the alcohol content in wine is significantly lower than in whisky etc.

About shaking: The guy at your friend's house is correct. Most of the scotch whisky sold is chill filtered, so there will be no sediments at all. However, more and more single malt whisky is sold unchillfiltered, and in a few cases (like the "Raw Cask" series from the independent bottler Blackadder) no real filtration at all. In the latter case you will indeed find sediments, and even small pieces of wood from the cask. And no, you really don't want to drink that...

So, the bottomline: Store your bottles upright, and don't shake when serving.

Enjoy your dram!

Dennis