Dry hopping technique

[McClellandBrew]

I have just brewed my first IPA of the Brew Season, (Living in Arizona with your brewery in the garage..not fun in the Summer).
On to dry-hopping this weekend. I have a theory. I've noticed that bigger breweries tend to add their dry hops to their fermentation tanks right before sealing them tight without any type of blow off. I understand that adding hops after fermentation will in fact give off co2 eventually carbonating your beer slightly. Sealing it off should create the most aroma in your beer, rather than slowly blowing out over 5 days.
I have done this in the past in a secondary corny, sealed it, and then kegged it a week later. The problem I ran into was once I opened the top of my secondary, the beer immediately started foaming out of the top, releasing all the pressure that had built up.
My theory is this. Do everything the same up until keg day, but cold crash for 2 days, still with dry hops in corny. Will the carbonation given off from the dry hops blend into the beer (rather than blowing off the precious aroma) like force carbonating a keg does when your beer is at ~38 F? Resulting in a very aromatic IPA to siphon into a keg?
My other thought is to pump 2psi of co2 into the secondary (corny) to push the Hop-carbonated beer into a keg for final force carbonation?
Any thoughts or experience on this method or a similar approach?

 

[day_trippr]

I understand that adding hops after fermentation will in fact give off co2 eventually carbonating your beer slightly.

Well, no. Fermentation creates CO2, and some of that is absorbed by the wort (temperature dependent). Dumping hops into fermented beer adds a crap ton of nucleation points (as well as a likely temperature differential - unless the hops were chilled down to the temperature of the beer) which causes CO2 that was dissolved in the beer to break out of solution. The result is clearly a net decrease in carbonation, not an increase.

My process is pretty simple: once a batch has fully fermented, I add free-swimming pellet hops, let that simmer for five days or so at around 68°F, then cold-crash down to 34°F before kegging. The pellet mush drops to the bottom of the carboy within 24 hours, then it's just a matter of how bright do I care to get the beer before kegging. It'll then sit for two weeks minimum at dispensing temperature and C02 pressure appropriate for the style before ending up in the keezer.

By waiting until fermentation has fully completed there's very little aroma character lost to "CO2 scrubbing". And as I don't even attempt to "naturally" carbonate beer there's no need to play with pressurized fermentation...

Cheers!

 

[McClellandBrew]

Thanks for the knowledge. I hadn't heard of nucleation points before.
So in your method, do you add your pellets and seal it with no bubbler or blow off? Then cold crash it 5 days or so later?

 

[day_trippr]

Thanks for the knowledge. I hadn't heard of nucleation points before. So in your method, do you add your pellets and seal it with no bubbler or blow off? Then cold crash it 5 days or so later?

I consider that the beer is still evolving CO2 even while the dry hops are floating about; and if I sealed up the carboy, bad things might happen when it gets cold-crashed. So I switch from a blow-off to an S-type air-lock on the carboy once primary fermentation has settled down, and keep it on through the dry hopping and cold crashing all the way to kegging. The S-type lock isn't subject to "suck-back" like a three-piece lock (or a blow-off into a catch vessel) and it really is a great solution for late-phase fermentation and crashing.

Yes, generally I dry hop for five days at ~68°F before starting the crash. Occasionally I'll push that by a couple of days but try not to go much longer than a week to avoid grassy notes from arising...

Cheers!