Dry Hopping under Pressure, Pre-fermentation Dry Hopping, Dry Hopping Cold

HomeBrewTalk.com - Beer, Wine, Mead, & Cider Brewing Discussion Community.

Help Support Homebrew Talk:


HBT Supporter
Mar 24, 2019
Reaction score
South Korea
Been reading a lot of Scott Janish blogs and trying out different hopping methods. I've dry hopped early in fermentation before, trying for some of that bio transformation I've heard so much about so I decided to start with pre-fermentation dry hopping and figured it would save me on some oxygen exposure not having to open the fermenter again until kegging.

I added 5 oz of pellet hops before pitching the yeast in a 6 gallon PET carboy (NEIPA recipe). Had my best efficiency ever on this batch and ended up with 6 full gallons. This was the first batch I've brewed since moving from a No Sparge HERMS recirculation mash to BIAB with HERMS recirculation. It's actually pretty crazy that my guessed estimates for conversion efficiency with the new method on this equipment profile were exactly right.

Anyway, so yeah the carboy was a bit fuller than I'm used to, a bit less headspace but I used a blow off tube with a solid stopper. This still resulted in the worst blow off I've ever had (pictures attached). Fermentation was vigorous and enough of the pre-fermentation hops were pushed all the way out to the end of the blow off tube where it got clogged. Enough pressure built up to launch the stopper where it impacted the lid of my chest freezer fermentation chamber. I wasn't home at the time but my wife heard it and had thought another large pigeon flew into the window again.

With most of the pre-fermentation pellet hops blown out the top of the carboy, I'm not sure how much extraction I got after the day to day and a half or so they spent in there before the blow off.

The next method I was eager to try out was dry hopping cold since Scott Janish wrote an article suggesting that hop oil extraction was actually faster at colder temperatures. I was thinking I could use the rest of my dry hops as keg hops after already having cold crashed then pressure transferred to the keg. I was hoping he would elaborate on this and other methods in his book "The New IPA," but that was mostly just scientific studies about different hop oils and not much to do with dry hopping methods. I changed my mind on this idea after doing a sort of hop tea experiment where I added a gram of pellets to some commercial beer and let it sit back in the fridge for 48 hours. I saw that this might be a good way of testing hop flavor and aroma but my experience was that the beers mostly just tasted and smelled like pellet hops and not the flavors that they produce in beer so I became skeptical about dry hopping under cold temperatures (crashed and kegged 37 F) and decided against it.

I still wanted to try dry hopping or keg hopping under pressure. Usually I force carbonate at high PSI and then have to relieve pressure to serving pressure and I hate losing all that hop aroma that comes out during the pressure release. So I got one of those corny keg lids with a ball lock post that attaches to an air stone. I cold crashed for two days so I could pressure transfer more easily and I just kegged the beer with the keg hops (6 oz) and now I'm trying to carbonate with the carbonation lid, letting the keg rise back to room temperature (68-70F) so I can still get hop extraction.

My carbonation chart shows that at that temperature and 11 PSI, my beer will still be under carbonated but I don't want to lower the temperature for the hop extraction and I don't want to increase pressure so I don't have to relieve pressure before serving. When I do finally cool it back to serving temperature, I'm assuming the beer won't magically be at my desired carbonation level (11 PSI at 37 F - 2.52 vol Co2). The beer will just be able to absorb more Co2 when the temperature has been dropped? So that's another day of carbonation I suppose but at least I won't have to vent the keg.

I'll probably leave the dry hopped keg at room temperature for 2-3 days. I had desired to dry hop loose in the keg. I ordered one of the dip tube / racking cane steel mesh filters produced by Utah Bio Diesel but I didn't have the right size stopper for it. I ended up suspending the keg hops from the carbonation stone in a nylon mesh bag.

I know someone is going to say why don't I then just ferment in the keg under pressure but besides the fact that I don't have a spunding valve, an XBMT experiment plus a Scott Janish article have me thinking fermentation under pressure is not going to produce the results that I'm looking for (maximum hop flavor and aroma in NEIPA that doesn't fade after the first week on draft).

blowoff3sm.jpg blowoff2.jpg blowoff1.jpg