Hops are essential for both the taste and the aroma of the beer!

Hops started out as a preservative and bittering ingredient for the beer but the brewers soon found out that different varieties of hops gave the beer a characteristic flavour and aroma. The art of hopping a beer had started! Today there are beers with so much hops in them that the beer itself is just a liquid in the background and the hops has taken over both taste and aroma completely!

There are two different groups of hops, those that are used mainly for the bittering of the beer ( they tend to have a high alpha acid content) and those that are used mainly for their aroma. There are some general hops as well that can be used for both bittering and aroma.

I tend to use a more moderate amount of hops in my beers since I'm not a big fan of the highly hopped IPA trend, I prefer my beers on the malty side of the taste spectrum. A typical beer for me has around 30-90g/1-3oz of hops in the recipe, depending on beer style and hop variety (alpha acid content mostly!)
I often use the american Cascade hop for its citrusy aroma and flavour, recently I tried out the Citra high-alpha hop in an Imperial Stout to see if I could ged a similar taste but with a higher degree of bittering per weight than the Cascade. Turned out OK, the beer is not ripe yet so the jury is still out on that one. I have also tried out the Amarillo hop with good results.
Another hop that I use quite frequently is the british Fuggles, a good general hop for bittering and aroma in british style beers. I'm also growing Fuggles hops in my garden!