Trying to undestand hops

Hi Guys!

I'm new to this wonderful hobby (5 batches so far) and still have many questions but the one that stands out right now is about bittering hops.

Do bittering hops only give bitterness to the beer, or do they give some flavor or aroma?

For example, this weekend I'm brewing an American Red Ale that calls for the addition of 1 oz of Cascade for bittering (60 min), 1 oz of Cascade for flavor (10 min) and another ounce of cascade for aroma (5 min). What would happen if I replace the bittering hop with another type of hop with the same AA and leave the flavor and aroma hops as Cascade?


Regards!
Mawa

This is a simplistic version of it:
Hops impart bitterness, flavor and aroma.
In a 60 min boil, hops boiled for the entire duration provide bittering.
Hops added toward the middle provide flavoring.
Hops added toward the end provide aroma.

Some hop varieties are better adept at one or two of these things, some can provide all three qualities well.

You can see why Cascades are popular in APAs.

Bittering hops do affect the flavor in the beer, just not to the extent of later additions. If you changed the bittering addition(s) but left the later additions the same, you'd probably not notice a difference unless your palate is incredibly precise. I worry less about my bittering additions usually and more about my later additions.

Mo betta info here:
http://byo.com/referenceguide/hops/

Nother one:
http://www.brewsupplies.com/hops_reference_chart.htm

It depends on the hops you use as well. When brewers talk about a "clean" bitttering hop such as magnum it is because when used as a bittering hop it has little affect on taste or aroma. Cascade on the other hand does. Given that you are using cascade for flavour and aroma additions in your recipe they will dominate and you would likely not notice much difference.

Switching from say Cascades to Chinook, you'd notice a difference, but most of the time a 60 minute boil will drive off the flavor & aroma of the bittering hop. It's a little like the base note for a perfume.