In a way ...Yes. It take less of the hop to achieve the same IBU's (Bitterness). But the Higher the %AAU the more chance of grassy flavours if used for flavour and aroma at higher IBU
General rule of thumb I use..High %AAU for bittering only...And Low %AAU for flavour and aroma
But hey there's still 12 opinions from another 11 brewers yet to come B)
Yes. You can achieve the same level of bitterness using more of a lower AA hop. Hallertau is a good example. At 4-5%AA, it is much less bitter than say Perle 6-8%, Northern Brewer 9ish%, etc but it adds a different type of bitterness. I use both high and low AA hops for bittering, depending on style. For example, I would not use Pride of Ringwood (Asutralia) or Northern Brewer (America) for bittering a Bavarian Weizen.
However, if you're using lots of flavour and aroma hops, the variety used for bittering matters less as you'll notice less of the bittering hop's flavour profile due to late boil additions of more flavoursome/aromatic hops. That's not to say you can't use high AA hops for flavour and aroma. Northern Brewer adds a woody character when used late in the boil, which is desirable for, say, a California Common.
Me too - I regard high AA% hops as being more efficient when it comes to their use as bittering hops early on in the boil.
That doesn't mean any old hops will do, however. You still need to match the hops that you like, for the particular brew you make. Experimentation, trial and error and learning the craft are all part of that process!
Batz, read the bjcp style guidelines to get an idea of what types of hops are appropriate for the style you're brewing and read THE DRUNK ARAB's spreadsheet of hop types in this forum. Then grab a tool like Promash (or do the maths) to work out the quantity if hops needed to get the IBU's you're after. A little bit of experimentation is fine, but to brew good consistent brews, it's important to get the IBU:gravity ratio right for the style you're brewing... a little hard with kits, but you're a partial mash + extract brewer, aren't you?
Anyway, the basic rule is the longer in the boil, the more bitterness and less flavour the hop contributes. So to bitter beer, add "enough" IBUs of hops at the start of the boil and for flavour, about 15-10 mins before the end, and for aroma, add at flame-out or dry hop.