Bitterness component of late hopping / dry hopping

[bwarbiany]

Found this and thought it was very interesting.

Essentially the old idea that whirlpool and dry hop additions don't add bitterness is completely false. It doesn't add bitterness due to isomerized alpha acids, but rather due to inherent oxidized compounds in the hops themselves, which are very bitter.

This wasn't well understood when most beers were primarily kettle-hopped with a small amount of dry hops added, but when brewers try to do things like hop-bursting and massive late or dry hop additions, they're actually adding the bitterness due to the huge quantity of hops added.

It sounds like nobody has figured out a calculation method for these additions yet, but something to think about for those big late-hopped beers.

[indianajns]

Great read. Thanks for sharing. I have always wondered about this but just assumed that my whirlpool additions were picking up all of that bitterness from the time it took my beer to go from 210 to 170ish. Wondering if the yet to come bitterning calculations will include age of the hops as a variable to incorporate oxidation....

[BrewMasterBrad]

Great article BW. Thanks for posting that. Interesting stuff.

I have played around quite a bit with hop bursting in my Pale Ale recipe with good results. You know, we've always talked about perceived bitterness in late-hop and dry-hop beers, and now this begins to give some scientific basis to it. Traditional lab IBU measurements only measure the isomerized alpha acids and don't account for all these late hop additions. I think it would be difficult to measure, as Greg mentioned, the actual effect with a formula since it really depends on how long the hops are held at a certain temperature. There are many variables, but it would be good to have some guidelines to go by.