Bittering hops.

I was wondering if it really matters what you use for you bittering hops (60+ min boil). A lot of recipes call for a 1 oz cascade or something that has low alpha acid like 4%. Could I recalculate using my software and use something with like 14% alpha so I can use less bitting hops or will it change the taste/aroma. I am just trying to be cheap and save a buck or less per batch.

Yes and no. I honestly don't think you're going to taste a huge difference as long as you get the AAUs right. Different hops do have different other chemical properties (other than Alpha Acids) that give them different bittering properties: some are harsher, some are smoother.

I have done exactly what you are describing with Columbus hops in several beers and have never been unhappy with the results.

Maybe if you taste tested both side by side, you'd taste the difference. Or maybe not.

Different hops have different ratios of the six primary bittering elements and the resulting bittering profile will change. Centennial is sometimes referred to as Super-Cascades, the profile is similar, but the AA% is three times as high. http://byo.com/referenceguide/hops/index.html is a good cross-reference.

I buy Columbus by the pound and use it unless there is a strong reason not to.