Dry Hopping Under Pressure

[Aeneas]

Hi all.

We ferment all our beers under pressure and have a Belgian approach, our head brewer/owner having previously brewed at Brasserie Dupont.

I, as new assistant brewer come from experience in New England and London and though I have done many, many Pale Ales/IPAs, I have never dry hopped other than through a good old dry hop port.

As this brewery ferments 100% under pressure and has no dry hop port (other than PRV port I suppose) what are the techniques people employ to dry hop?

I imagine utilising a second vessel, purged and sanitised, filled with hops and then recirc beer through that vessel?
Is contact enough just with recirc or does one need to 'push' the dry hop charge into the main fermenter?

Thanks in advance for your suggestions.

Cheers.

[Aeneas]

Bumping this one.

It seems that pushing a volume of beer into a pre charged secondary vessel to create a sludge that can then be pushed into the fermenter is working for some.
All done with CO2.

Gonna try that and report back.

[sittinginthesky]

I can chime in here with what we used to do at the previous, large volume production facility I worked at. It mirrors your exact suggestion. We used a hop cannon as our secondary vessel. The FVs proved to be too big to charge hops up through the dry hop lines, so we used it as a holding vessel instead, particularly because it was capable of handling an intense amount of pressure. We purged the cannon, dumped roughly 55 lbs. of hops in, backfilled with wort, recirced in the cannon for a few minutes, and then recirced it through the FV for roughly 20 minutes before pushing it all into the tank and then repeating the process. It seemed to work pretty well. I believe - though I'm not positive - that we'd recirc the tank for roughly 24 hours after completing the dry hop dose. Not positive on that one though. Keep in mind that the constant agitation should cut the uptake time for your hop compounds, but I may be wrong on that. I know there's some competing opinions there, so I'm more than open to correction.

Edit to add: I should have mentioned (though it may go without saying) that we recirced with the cannon under pressure the whole time.

[Aeneas]

Thanks buddy! We used the method described and have been getting good results. As you say, good fast extraction this way. Cheers.