Bittering Hops

How much flavor comes through from the type of bittering hop you use? Is it perceptable? Would you be able to tell the difference between, say, centennial and chinook for example? I assume there must be some differences that come through, otherwise there wouldn't be so much variability in which bittering hops are used.

Also, if your recipe calls for a certain amount of bittering (ex. northern brewer) hops at say 10%AA, but the hops you have (northern brewer) are 8%AA, and you adjust the amount you add so that the IBU's are the same as in the recipe. Will you notice any difference?

Thanks

Sure there is some perceivable flavor that comes from bittering hops but, for the most part it is minimal and it usually comes down to the "type" of bittering that matches well with the beer.

By type, I mean that some hops impart a very smooth, mellow bitterness at the lowest end of the spectrum (usually low alpha Noble) and at the other extreme, a rather harsh, biting bitterness comes out of some others.

A good deal of that is also an effect of you water chemistry too.

The IBU numbers are an average for the batch harvested and, calculations based on those numbers are for "ballpark" reference. So, IMO, Yes. There will be a slight difference but minimal and to discern the difference you would have to do a side by side.

There are 6 different main constituents that make up the bittering, flavor, and aroma that any particular hop will impart to a wort. Even subtle variances in those levels make for a "different" hop. Some of the constituents are extreme and others are very subtle.

For more about what it is in the hop that makes our beers tick I suggest you read George Fix - Principle of Brewing Science or Lee Jonson - Brew Chem 101.They both offer some pretty descriptive sections on the Lupulones (sp) and Humulones (sp). There are some other compounds in there too that effect the hop chracter (myrcene).

It's a good read but, can get kinda techy plus, given that we usually only see the tested Alpha numbers and only see the rest if we dig (even then they are avreage for the strain) deep enough.

Homebrew information has evolved a great deal in the 2 years I have been doing it, so it's very well possible soon we will receive the same respect that the breweries get and then the specific numbers will be divulged to us.

As a novice, don't take anything I say as gospel, but as I understand it:

You should not be getting any flavor nor any aroma from your bittering hop. However, different hops do bitter differently, if that makes sense... it is a different type of bitterness between hop varieties. This is much less perceptible, however, than the differences in aroma and flavor.

If you adjust the quantity of the bittering hop to equal the recipe it should not make a difference, assuming you are using the same hop. (If the Recipe calls for 1oz. Northern Brewer 10% you would not notice a difference using 1.25oz. Northern Brewer 8%. You most likely would notice a difference, however, if you used 2.2oz Cascade 4.5%).