My theory and experience with Biotransformation of dry hops in a NEIPA.

[stickyfinger]

Regarding biotransformation: I have been under the impression that any time we dry hop in the primary we are getting some biotransformation. The reason for this belief is that I have added hops to a cold, carbonated keg of IPA before, and I found the hop character to be completely different from a beer in which hops have been added at any point in fermentation (prior to packaging.) The beers with hops added to the cold, carbonated beer have a VERY strong flowery, perfumey character - I think geraniol is a major player here, as I feel like I am smelling a geranium plant when I drink beers that I have had hops added after packaging.

I did do a 24 dry hop one time and cold-crashed right after. That beer had an intense character that I wasn't used to. Maybe it was a combo of biotransformation and some non-biotransformed compounds in the beer.

I'm very interested in how The Alchemist gets their hop flavor. It is known that they partially crash to 50s and dry hop there? I had heard that they dry hop on the cool side.

 

[beervoid]

Regarding biotransformation: I have been under the impression that any time we dry hop in the primary we are getting some biotransformation. The reason for this belief is that I have added hops to a cold, carbonated keg of IPA before, and I found the hop character to be completely different from a beer in which hops have been added at any point in fermentation (prior to packaging.) The beers with hops added to the cold, carbonated beer have a VERY strong flowery, perfumey character - I think geraniol is a major player here, as I feel like I am smelling a geranium plant when I drink beers that I have had hops added after packaging.

I did do a 24 dry hop one time and cold-crashed right after. That beer had an intense character that I wasn't used to. Maybe it was a combo of biotransformation and some non-biotransformed compounds in the beer.

I'm very interested in how The Alchemist gets their hop flavor. It is known that they partially crash to 50s and dry hop there? I had heard that they dry hop on the cool side.

What you are describing sounds more like the effect of dry hopping on different temperatures.
There is research out there that shows different temps extract different flavours.
Warmer is more fruity, colder is more earthy grassy.
I just dry hopped a kveik ipa with a biotransformation hop experiment at 36c. It smelled like rotten fruits.

 

[couchsending]

Regarding biotransformation: I have been under the impression that any time we dry hop in the primary we are getting some biotransformation. The reason for this belief is that I have added hops to a cold, carbonated keg of IPA before, and I found the hop character to be completely different from a beer in which hops have been added at any point in fermentation (prior to packaging.) The beers with hops added to the cold, carbonated beer have a VERY strong flowery, perfumey character - I think geraniol is a major player here, as I feel like I am smelling a geranium plant when I drink beers that I have had hops added after packaging.

I did do a 24 dry hop one time and cold-crashed right after. That beer had an intense character that I wasn't used to. Maybe it was a combo of biotransformation and some non-biotransformed compounds in the beer.

I'm very interested in how The Alchemist gets their hop flavor. It is known that they partially crash to 50s and dry hop there? I had heard that they dry hop on the cool side.

Yeah I believe what you’re describing is more temperature related than anything else.

As far as the Alchemist process goes we know a few things. Their beers are only dry hoped once with a relatively small amount of hops compared to today’s “standard”. Based on info in the IPA book and what I’ve seen on their Instagram page and other experiences at the brewery, they’re cooling to a rather low temp after fermentation to get Conan to flocc then after pulling yeast adding pellets in a large bag in a Grundy of some sort and recirculating for a period of time. No idea if they’re letting the temp rise over those few days or not.

We know he’s said 4-5 days for contact time. Their hoppy beers are always a blend of 3-4 different tanks into one bright... or at least Heady brewed in Waterbury is.

 

[Cevan65]

I would like to hear from people that go on the higher side of dry hopping (10oz+) and would be curious to know if they do dry hop during active fermentation? and if they have dry hopped only after active fermentation if they noticed a difference?

I brewed two 3 gallon batches using the same grain bill. Only difference was one was DH'd during fermentation and the other after fermentation. Each had 4 oz towards the end of the boil thru 170 degrees and 4 oz DH. Neither had any harshness. The one DH'd during fermentation had more hop aroma and taste. I've stopped DDH for now as I feel it isn't worth the risk of infection (and TH doesn't do it ;-).

 

[wepeeler]

For my neipas, I get a sweet/extra juicy flavor from biotransformation hopping. I believe the idea behind the biotransformation is that the yeast interacts with the hops and help produce flavors that hops alone can't impart. Dry hopping during fermentation not only produces these flavors, but also helps drive out the O2 introduced by the act of dry hopping. Personally, my beers have never lacked aroma, so I don't fully buy into the idea that the fermentation is driving off hop aroma. I've dry hopped anywhere from day 1 up to the day before kegging (everything goes into keg within 14 days), and I've settled on 1st dry hop on day 2 (I brew Thursday evening, dry hop on Saturday), then another dry hop 3 days before keg. 6 gallon batches, 2 x 3 oz dry hops. I've tried all 6 oz dry hops at once, and I'm not as happy with the results. Flavor is there, but aroma is lacking. I do find that if I include Galaxy, there is a bit of burn, although I'm not convinced it's all the hops. Yeast can give a burn as well. I find the beer mellows and tastes best after being in the keg for 2 weeks. So, 2 weeks primary, keg, then 2 weeks after it begins to peak. Never had one go longer than 6 weeks in the keg, so I can't vouch for anything beyond that. I will say though, my last neipa was an all Mosaic, and I really couldn't stand it the day after I kegged it (of course I have to sample it!). By the last pour, I was pissed that I gave so much of it away so early, because it was FANTASTIC after sitting in the keg for 4 weeks. You live, you learn...

 

[eugles]

On the recent CB&B podcast Aslin also noted that they don’t dry hop during fermentation, same with Monkish among others. It’s literally wasting hops.

After negative for diacetyl drop to 50/55/60 (depending on you yeast) with head pressure. Let sit for a day or two. Pull as much yeast as possible. Let climb back up to 60 and dry hop for 3 days between 60 and 65. Add all at once or split it up. Rouse once or twice with Co2. Crash or gradually cool as low as you can. Let sit for a few days. Transfer and carbonate.

Aussie hops are especially high in polyphenol content. The harsh bitterness and chalky taste comes from polyphenols. They generally need more time at lower temps to settle out and your beer will be much much more enjoyable. You can also use a smaller dose of biofine and don’t worry you won’t lose haze.

I add equal amounts of hops to the kettle as I do in the WP and my beers are in no way bitter. Bitterness is perceived at the front of your palate. If you are perceiving harshness at the end of the palate that’s from water/tannins/polyphenols/yeast not from IBUs.

Most of the best commercial examples are dry hopped at rates around 4lbs per barrel. I’ve seen Monkish do a 9lb per barrel DH as well. Some would say over 2lbs per bbl is a waste. I definitely notice a difference between 2 and 4. My 6 gallon batches usually get 10-12 ounces always after fermentation. Less yeast in your beer more aromatics you’ll get. And don’t worry if you use juicy hops you’ll still get juicy flavors even if you don’t add them during fermentation.

I'm following the exact same practice on my current brew after listening to the same podcast. Wondering what would rousing look like in my dry hop corny keg? Should I shake it up, or actually push some co2 through the liquid post?

 

[couchsending]

I’d just push some Co2 through the liquid out a couple times.

Just re-listened to a great MBAA podcast with Ben Edmunds from Breakside. He talked about their dry hopping procedure and how they had tried everything from recirculation to torpedos etc. and had gone back to the old fashioned way of adding them through the top while sending Co2 through the CIP arm. They also rouse with Co2 but he said they couldn’t tell the difference between one roused only once and one roused 4 times.

 

[eugles]

I’d just push some Co2 through the liquid out a couple times.

Just re-listened to a great MBAA podcast with Ben Edmunds from Breakside. He talked about their dry hopping procedure and how they had tried everything from recirculation to torpedos etc. and had gone back to the old fashioned way of adding them through the top while sending Co2 through the CIP arm. They also rouse with Co2 but he said they couldn’t tell the difference between one roused only once and one roused 4 times.

Awesome thanks! I'll check out that podcast as well. I'm on a mission to recreate Reciprocal from Bissell Brothers after trying it this summer in Maine. I feel i have the mouthfeel and taste down pretty well, but super lacking in the aroma dept.