I can tell you this:
No chilling definatly increases your bitterness and decreases your aroma/flavour.
I have had very similar results to NickB, and have also moved to just bittering and flameout, maybe some dry hop for aroma.
Its pretty simple, you boil hops for longer to get more bitterness, when you no chill you are effectivly keeping the hop compounds (flavour and aroma) almost at boiling (80-90 degrees) for a longer period of time therefore convertying some of theem to bitterness.
I have also found that its probably about 5IBU of difference so i always bitter my beer to 5 ibu less than i want.
I have also found that different hops have different amounts of "extra bittering" from cubing, i think that probably has something to do with teh Beta and alpha... not sure about that part....
thats my experience anyway, YMMV
No-Chilling is almost destined to increase your bitterness - if you add late boil hops. The alpha acids from your 30min and 5min hops are going to stay dissolved and keep right on isomerising the whole time the cube is hot. There is no phsical agitation and the heat is lower than in a boil, so it wont be as high a rate, but its still going to happen.
The last two beers I made, I no-chilled taking this stuff into account.
The beers got no "late" hops, although they did get a small 30min addition for complexity in flavour - I do "cube hop" which I more or less treat as a flavour addition, it also gives a reasonably significant amount of bittering ( I calculate it to be the equivalent of a 20min addition with the same amount of hops) For aroma, there are no kettle additions or cube additions at all. - I
Ultra Late Hop using a technique that is very similar to the "French Press Hopping" technique describe recently in BYO and on Basic Brewing Radio.
The Aroma addition is not added until 2/3rds of fermentation is complete - The hops are placed in a french press coffee maker, stirred and steeped for about 1min - then its pressed and the hot liquid is poured into the primary - the process is repeated to "sparge" the hops. You could steep for longer if you want, but I am trying to emulate the short contact time and rapid cooling you get from a hopback, so I keep the contact time to less than one minute.
The Vienna Lager that won champion beer at vicbrew - was aroma hopped in this fashion, although in its case, the hop juice was poured directly into the pre-filter keg and the beer was lagered for several weeks before filtering. I found that this gave a "vegetal" edge to the hoppiness, but it dissipated nicely with filtering and lagering. When the Ultra Late Hops are added to the fermentor... the vegetal thing does not seem to happen, but the hop character is not quite as pronounced.
The reason for all that versus a simple dry hop.... well, it doesn't smell or taste like dry hop, it smells and tastes like late addition hops.
I will keep experimenting with this as an easy way to compensate for the aroma decrease I see in no chill - so far I am happy with the results and I think it can be refined to te point where the affect of No-Chill on hop flavour/aroma can be completely compensated for.
Thirsty
