Dry hopping during active Fermentation

[JONNYROTTEN]

I'm going away for a few days and dry hopping during active fermentation will leave me with finished beer when I get back.

My question is they say doing so blows the flavor/aroma out the airlock.
If hop oil is whats doing the flavoring how is this possible?

The oil is the oil and sits in the fermenter like an oil slick. The oil doesn't vaporize to a gas and become airborne and get blown out the airlock just because fermentation is taking place so how is it possible to loose effectiveness?

And even if it did somehow adding a pellet or 2 more would make up the difference.

What Am I missing?

 

[Homergah]

There are many stages of active fermentation. How far along are you?

 

[RM-MN]

I'm going away for a few days and dry hopping during active fermentation will leave me with finished beer when I get back.

My question is they say doing so blows the flavor/aroma out the airlock.
If hop oil is whats doing the flavoring how is this possible?

The oil is the oil and sits in the fermenter like an oil slick. The oil doesn't vaporize to a gas and become airborne and get blown out the airlock just because fermentation is taking place so how is it possible to loose effectiveness?

And even if it did somehow adding a pellet or 2 more would make up the difference.

What Am I missing?

Have you ever been next to a diesel pump at the gas station and smelled the stink from that diesel? That's an oil. How about a peppermint patty? That peppermint smell is an oil. Not all oils vaporize so quickly but some do.

 

[JONNYROTTEN]

There are many stages of active fermentation. How far along are you?

I havent brewed yet. Brewing tomorrow and was going to dry hop on Wed. Using 05 yeast. So I'm figuring I'll be right at the height of active fermentation

 

[Homergah]

I havent brewed yet. Brewing tomorrow and was going to dry hop on Wed. Using 05 yeast. So I'm figuring I'll be right at the height of active fermentation

Krausen will have fallen by then. Perfect. Sure some constituents will be driven off, but that's the case regardless of where/when you hop.

 

[JONNYROTTEN]

Have you ever been next to a diesel pump at the gas station and smelled the stink from that diesel? That's an oil. How about a peppermint patty? That peppermint smell is an oil. Not all oils vaporize so quickly but some do.

Pretty much everything on the planet has a smell. THat doesnt mean its losing oil potency.

Using your diesel analogy, Whether I'm pumping it or I let it sit in a can 5 years it still smells like diesel.

Hops fade in a beer with time but regarding dry hopping during active fermentation or 3 days later your not losing any flavor in that short time period.

oil is oil and sitting in the liquid. I dont see how the SMELL of the oil in the airspace above the liquid being removed is lowering the infused oil effectiveness over a 3 day period.

Not being snarky I just dont see how removing a smell in the air effects the beer flavor.

For another analogy our weed growing friends use carbon filter to scrub the AIR around there weed plants which is INCREDIBLY strong odor the entire grow cycle and leaves next to no odor in the grow room....yet it has ABSOLUTELY zero effect on the smell or taste of the finished product. And they make weed oil out of weed.

Seems like the same concept.

 

[RM-MN]

oil is oil and sitting in the liquid. I dont see how the SMELL of the oil in the airspace above the liquid being removed is lowering the infused oil effectiveness over a 3 day period.

Oil is a whole class of liquids. Some lose little volume to the aroma, some a lot more. Look at your diesel can and see the volume of oil in there. Look at the leaf of a hop. See any oil there? There just isn't a big volume of the oil to start with so it can all evaporate except for the heavier or more viscous parts, that which you see on the surface of the beer.

 

[Vale71]

That CO2 leaving through the airlock has first travelled as tiny bubbles through the beer before leaving. It's called CO2 scrubbing, you can remove all sorts of unwanted aromas such as rotten eggs smell through this process.

 

[JONNYROTTEN]

That CO2 leaving through the airlock has first travelled as tiny bubbles through the beer before leaving. It's called CO2 scrubbing, you can remove all sorts of unwanted aromas such as rotten eggs smell through this process.

Ok..thats something I havent seen before. Makes sense.

What about hopping at low temps say 145-160 to stop isomerization to preserve the hop oils.Wouldnt that hop oil then be scrubbed being it goes straight into the fermenter? THat method is proven to give more flavor/aroma.

It seems like if anything actually is being scrubbed and I'm not sure how it could ever be proven it would be minimal at best

 

[HTH1975]

Read up on hop bio-transformation. In a nutshell, you will get flavour/aroma that you would not get any other way. Said to be more floral notes with this process.

I’ve tried it and wasn’t convinced. I’ll stick to dry hoping once I’ve cold crashed.

 

[JONNYROTTEN]

Read up on hop bio-transformation. In a nutshell, you will get flavour/aroma that you would not get any other way. Said to be more floral notes with this process.

I’ve tried it and wasn’t convinced. I’ll stick to dry hoping once I’ve cold crashed.

Interesting. A quick read on bio-transformation on a couple different sites show adding hops during fermentation actually adds MORE hop flavor/aroma..which is the opposite of the scrubbing theory.

Sounds almost like brewers don't have the scientific grip on actually whats happening yet.

 

[HTH1975]

Interesting. A quick read on bio-transformation on a couple different sites show adding hops during fermentation actually adds MORE hop flavor/aroma..which is the opposite of the scrubbing theory.

Sounds almost like brewers don't have the scientific grip on actually whats happening yet.

I don’t think anyone really fully understands what is going on yet. I’ve only tried dry hopping during active fermentation once, so it’s something I’d like to try again one time before completely writing it off.

 

[vtipsy]

Interesting. A quick read on bio-transformation on a couple different sites show adding hops during fermentation actually adds MORE hop flavor/aroma..which is the opposite of the scrubbing theory.

Sounds almost like brewers don't have the scientific grip on actually whats happening yet.

Often people double dry hop. Once during active fermentation and once after it's complete (or almost complete).

Experiment ... try it out for yourself.

 

[Qhrumphf]

CO2 scrubbing isn't an all or nothing thing. You're gonna lose aromatics through the airlock. Nucleation means dry hopping at the end of fermentation also scrubs out aromatics, especially if not in a sealed fermenter.

It's part of the process. And if anything if you're not applying positive CO2 pressure during a normal dry hop (most homebrewers don't), or if you cold crash while not under positive CO2 pressure (which most homebrewers do), the damage from oxygen will far outdo anything scrubbed out by CO2. Dry hopping during active fermentation it's still releasing it's own CO2.

 

[JONNYROTTEN]

Often people double dry hop. Once during active fermentation and once after it's complete (or almost complete).

Experiment ... try it out for yourself.

I'll probably do that just for the hell of it. But the point of the thread was to find out how dry hopping during active fermentation scrubbs flavor/aroma and it seems it might possibly ADD flavor which I wasnt expecting.

I still dont understand if it scrubs flavor then how would adding hops at at lower temps say 145 to extract as much hop oil as possible without isomerization why arent those oils evaporating during active fermentation? As far as I know and I could be wrong but but extraction happens quickly at 145 compared to 68 deg for days, but is essentially its the exact same thing...so again why is it those hops can go in the fermenter as standard process but adding hops during the fermentation will strip flavor?

 

[RM-MN]

The hop oils aren't all one boiling point. There are many different oils. Some evaporate quickly, some slowly, some at room temp, some only near boil.

 

[vtipsy]

I'll probably do that just for the hell of it. But the point of the thread was to find out how dry hopping during active fermentation scrubbs flavor/aroma and it seems it might possibly ADD flavor which I wasnt expecting.

I still dont understand if it scrubs flavor then how would adding hops at at lower temps say 145 to extract as much hop oil as possible without isomerization why arent those oils evaporating during active fermentation? As far as I know and I could be wrong but but extraction happens quickly at 145 compared to 68 deg for days, but is essentially its the exact same thing...so again why arent those hop oils evaporating?

My understanding is that hops contain a bunch of different aromatic oils, some more volatile than others. Adding hops during the boil will drive off the more volatile compounds but some will remain and contribute a flavor -- a different flavor to those boiled off. Adding hops late in the boil drives off less than adding earlier in the boil. Same goes for dry hopping during active fermentation. Here some kind of magical process occurs (read as "I don't understand it") called biotransformation, this contributes or 'adds' a flavor from the hops that is different to a post fermentation dry hop but due to c02 scrubbing you will also drive off some of the volatiles that you would get from a post fermentation dry hop. A second round of dry hopping is done to add these back into the mix. Adding hops at all these different stages builds up a broad profile of the various hop compounds.

 

[Vale71]

And hop oils have nothing to do with isomerization, you're mixing up oils and alpha-acids which are completely different things.
And adding hops during cooling at 145 is in no way the same thing as dry-hopping at 68.

 

[vtipsy]

It's part of the process. And if anything if you're not applying positive CO2 pressure during a normal dry hop (most homebrewers don't), or if you cold crash while not under positive CO2 pressure (which most homebrewers do), the damage from oxygen will far outdo anything scrubbed out by CO2. Dry hopping during active fermentation it's still releasing it's own CO2.

I'll quote this just to give it emphasis. Adding hops post fermentation will introduce oxygen which will dull the hop aroma and flavor. In fact, maximizing hop flavor and aroma is real gauntlet.

 

[HTH1975]

I’ll leave this here... https://www.brewersjournal.info/the-effect-of-dry-hopping-on-fermentable-sugars-and-abv/

 

[Qhrumphf]

I’ll leave this here... https://www.brewersjournal.info/the-effect-of-dry-hopping-on-fermentable-sugars-and-abv/

Ahh hop creep.

This has been known for quite some time, and really seems to have exploded with the experiment Allagash did and presented a few years back.

I'm amazed it's taken this long to filter into the homebrew world.

My non-active fermentation dry hops (ie normal ones) I prefer to do prior to fermentation ending but as it's slowed, and then cap at the same time. Avoids volatile loss to scrubbing, and I find it helps mitigate the impact of hop creep and speed the cleanup (most importantly its tendency to leave diacetyl precursors in its wake).

 

[couchsending]

Biotransformation, I believe, has only been scientifically tested to actually happen with very few yeasts. Most of the testing was conducted with 34/70. Maybe add a little 34/70 to your next IPA and see.

In my opinion waiting until the beer is 1 Plato from terminal is the best time to add some dry hops if you want to add them during fermentation and think biotransformation is a thing. Matt Brynildson is the guy that popularized the biotransformation theory. He was a hop chemist. He waits until right before terminal. I trust him. Anything before that you are seriously reducing the impact of those hops. Not only will volatiles get blown off but oils will get dragged down with floccing yeast. You also run the risk of hindering fermentation by adding all that hop matter at peak activity.

The only way to get maximum aroma is to wait until fermentation and D-rest are complete, soft crash to get as much of the yeast to flocc, pull the yeast then add dry hops. The key is to get as much yeast out of the beer as possible. Unless you have a conical this is really hard to do on a Homebrew scale so you’re better off adding the hops at the tail end of fermentation to prevent O2 pickup.

Pitch rate and pH are two other variables to consider with hoppy beers. They might have a bigger impact on the final beer than when and how you add dry hops.

 

[vtipsy]

Pitch rate and pH are two other variables to consider with hoppy beers. They might have a bigger impact on the final beer than when and how you add dry hops.

Hey couch, care to elaborate on this?

Cheers.