I thought I would outline most of the options most homebrewers have for methods of dry hopping this style. I ferment in 5 or 10g corney kegs with filters on them and can’t dump yeast - I think most of us are without conicals and deal with this.
If priority is minimal O2 exposure.
1. Open fermenter during active fermentation dump hops. Cold crash out yeast and hops, closed transfer to serving keg. This can be mid fermentation or late fermentation for varying effects.
If priority is crashing out yeast.
2a. Ferment all the way out, cold crash out yeast. Open fermenter while co2 running in thru gas post, dump in hops, close up and purge. Cold crash again. Closed transfer to purged serving keg.
2b. Better yet for getting off the yeast would be crash out yeast, transfer off into purged dry hopping keg. Open DH keg to dump in hops like above. Cold crash and transfer into purged serving keg.
Creative options trying to combine low o2 and crashing out yeast:
3a. Finish fermentation, crash out yeast. Add dry hops to a DH keg, use multiple CO2 purge cycles to try to get rid of most of the O2. Transfer into DH keg. transfer into purged serving keg
3b. Alternatively, you can use the CO2 produced from Fermentation to purge out the DH keg for a couple days during fermentation. Crash out yeast, transfer into semi purged DH keg. transfer into purged serving keg.
3c. Is the same as option 3b but instead of flushing a DH keg filled with hops, you suspend a bag of hops to the fermentation lid and later release it by pulling magnets
My thoughts:
Option 1: most likely to have hop burn, possibly muddled hop aroma.
Not sure if there is less oxidation with 2b or 3a, I think its debatable.
3b or 3c is questionable in my mind as you are leaving the hops open for several days and maybe the aroma is being flushed out by the co2?
I don't know what method I like most... It seems the prominent voices on this thread get better results with option 2a. I have had oxidation problems doing this and I have to move my keg a little bit to add the hops so I lose the effect of the crash by stirring things up again.
Most of the internet seems to swear by some version of option 1. It doesn't seem as intelligent as option 2a and several pros recommend to do some version of 2a. But, I have consistently had the best results with option 1... maybe I like a little hop burn? maybe I havn't been able to really pull off option 2 correctly?
I'd like to hear others opinions, if nothing else I hope this is a resource for people to see the different options spelled out.