Since the hop resins bind to the yeast, if you can drop most of the yeast out before you dry hop you will have better hop aroma. I wait till fermentation is finished, crash 10 degrees, wait a week and (if possible) dump yeast. Then add dry hops.
Otherwise you will notice that beer is very hop aroma forward when still cloudy with yeast but loses hop aroma much quicker as beer clears.
This makes sense. However, I've heard hops can develop a vegetal/grassy flavor/aroma when added at lower temps. I've never had this experience since I usually pitch after fermentation is complete and I've ramped the temp up a few degrees to help the yeast finish. I have noticed that some of the beers, upon clearing up will lose aroma. Have you experienced the vegetal/grassy notes I've heard about?
14 days of dry hopping at ale fermentation temperature seems like a LONG time.
If you want shortest time from grain to glass (with maximum amount of dry hop impact), you can tweak a few things in your process:
1. Start with healthy, active yeast and O2. Seems like you're pretty much there. An active yeast starter and an additional shot of O2 6-8 hours in may cut a day or so off primary fermentation. I've shortened primary (and conditioning) time even further by using an English yeast (S-04 or 1968 slurry), but if you don't like the attenuation levels or yeast flavor contribution, don't bother.
2. More hops, higher temp, less contact time. Matt B. from FW likes to dry-hop at the end of primary (>90% attenuation, lets say 2 SG points from target) for just 2-3 days, but with a large charge of hops at diacetyl rest temps.
I use his method - in the case of a 1.068 IPA, 3 oz hops for 2 days in primary. Matt does have the luxury of dropping the yeast to reduce the absorption as Keith mentioned, but at these hopping rates your bound to get a lot of extraction either way.
3. Dry hop twice: 75% of the total dry hop charge for 2-3 days at the end of primary, the other 25% for 3 days in the keg, before going into the kegorator. This brightens up the dry hop flavor/aroma and allows you to minimize O2 pickup during the last dry hop (add to keg before transfer and purge well).
Just my $0.02. Like with most things in brewing - there is no 'best' method!
The 14 days of dry hopping is two charges of hops. So the longest would be 14 days. It may be too long I suppose. I like the idea of adding all of the dry hops at the end of primary. I really have no way to drop the yeast off since I'm using carboys and I really prefer not to rack to secondary. I could crash a few degrees I suppose, but that depends on what's in the fermentation chamber with the beer I'm crashing and what stage it's at.
Good question. For years I did what most people here do - wait until after high krausen subsides to add dry hops, for the reasons you mentioned. Works fine. But after reading an article by Stan Hieronymus in Zymurgy a few issues issues ago, I tried his method, which was to rack to a secondary after fermentation and add dry hops away from the bulk of the yeast, when the beer was fairly clear. I used a hop combo that I had used before, and I found the overall hop character to be a little better. He reasoned that some hop aroma/flavor compounds are formed in the presence of high levels of suspended yeast that are not thought of as desireable. I think I will keep using his method as I had good results, but I spent years dryhopping after high krausen and made good beer then too. Either way you will too.
After reading the same article, I did a little experiment recently. I brewed 2 batches of the same beer. One I let sit in primary for 4 weeks, then dry hopped with Amarillo. The other I racked to secondary after 2 weeks, then dry hopped with Amarillo for 2 weeks. The first batch developed a weird, intensely fruity aroma from the dry hops...not what I expect from Amarillo. In the batch that had been removed from the yeast, I got the tangerine/lemon aroma I expect from Amarillo. I'm convinced.
Very interesting. So you always rack to secondary now?