[dilluh98]

Looking to do a 12 day and 5 day dry hop on a IIPA. Fermentation is far beyond peak but there's still a little activity and I'd like to do the first dry hop charge tomorrow. I don't have a ton of experience in the dry hop realm. Is this going to affect the fermentation? Should I wait until fermentation looks to be completely done?

[HoosierBrew]

Won't affect fermentation at all. A lot of brewers dry hop as fermentation winds down. My current method is to dry hop when the beer has cleared out well (in keg), but I've used both methods and had good results. No worries.

[brewinhard]

Yep.  Agreed.  I don't think you need a dry hopping schedule lasting 12 days, but you can do it how you want.  You may want to consider adding a bit more dry hops to compensate for any hop aroma being pushed out by the remaining CO2 escaping during the tail end of the fermentation. 

I have good results doing this and typically only use a 5 day dry hop (usually around 6-8 oz/5 gallon batch).

[SPAMR]

Yep.  Agreed.  I don't think you need a dry hopping schedule lasting 12 days, but you can do it how you want.  You may want to consider adding a bit more dry hops to compensate for any hop aroma being pushed out by the remaining CO2 escaping during the tail end of the fermentation. 

I have good results doing this and typically only use a 5 day dry hop (usually around 6-8 oz/5 gallon batch).

Same here, 5 days with 6 oz., but I'm still new!

[Ethan J]

For my IPAs and IIPAs, I'll do 2 rounds of dry hopping lasting 3 days each, beginning after primary fermentation has died down (usually day 4-7). I leave the first round in until packaging, so in reality the first round is in for 6 days, but overlaps the second round by 3 days. I cold crash on day 6 and package on day 7 after dry hopping. As far as hopping rates go, I usually match my flameout/whirlpool addition in the first round of dry hopping, generally around 1-2oz per gallon. This then leaves room to tweak the aroma with the second round, based on what I want to bring out. Regardless, experiment with it and you'll find out what works best with your system and your tastes.

[westcoastbrew]

I always wait until fermentation has completed.  That way the CO2 does not carry the hop aroma out of the fermenter as it escapes and instead stays in contact with the beer.

[erockrph]

I always wait until fermentation has completed.  That way the CO2 does not carry the hop aroma out of the fermenter as it escapes and instead stays in contact with the beer.

I'm going to call BS on this as an old brewer's tale that just makes no sense to me whatsoever. If the hop oils are in solution, then there is little risk of CO2 in gas form removing it from the beer. Hop aroma compounds aren't some magical substance that evaporates rapidly at room temperature (after it is already dissolved in solution, mind you) if you look at it the wrong way.

[denny]

I always wait until fermentation has completed.  That way the CO2 does not carry the hop aroma out of the fermenter as it escapes and instead stays in contact with the beer.

I'm going to call BS on this as an old brewer's tale that just makes no sense to me whatsoever. If the hop oils are in solution, then there is little risk of CO2 in gas form removing it from the beer. Hop aroma compounds aren't some magical substance that evaporates rapidly at room temperature (after it is already dissolved in solution, mind you) if you look at it the wrong way.

I'm not so certain. I think I've had it happen.

[erockrph]

I always wait until fermentation has completed.  That way the CO2 does not carry the hop aroma out of the fermenter as it escapes and instead stays in contact with the beer.

I'm going to call BS on this as an old brewer's tale that just makes no sense to me whatsoever. If the hop oils are in solution, then there is little risk of CO2 in gas form removing it from the beer. Hop aroma compounds aren't some magical substance that evaporates rapidly at room temperature (after it is already dissolved in solution, mind you) if you look at it the wrong way.

I'm not so certain. I think I've had it happen.

And it was specifically from CO2, as opposed to some other mechanism like hop oils sticking to yeast in suspension and falling out? I'm not saying that dry-hopping during fermentation might give less hop aroma, I'm just suspicious of the claim that it is because of CO2 blowing it out.

[denny]

And it was specifically from CO2, as opposed to some other mechanism like hop oils sticking to yeast in suspension and falling out? I'm not saying that dry-hopping during fermentation might give less hop aroma, I'm just suspicious of the claim that it is because of CO2 blowing it out.

I can't really say one way or the other.  Like your theory, I'm just guessing.

[narvin]

Bubbling CO2 through beer is a well known technique that can scrub aroma and flavors, so why not hops?  It may not reduce IBU but I'd bet it can remove some volatile compounds from dry hopping.  If your fermentation is almost done, it may not remove much in practice.

[erockrph]

Bubbling CO2 through beer is a well known technique that can scrub aroma and flavors, so why not hops?  It may not reduce IBU but I'd bet it can remove some volatile compounds from dry hopping.  If your fermentation is almost done, it may not remove much in practice.

Good point. The question is how much it would actually remove in practice. I have an old keg of IPA I've been meaning to dump to make room for some new batches. Maybe I'll throw a couple of ounces of hops in the keg for a few days then go through some purge/degas cycles to see what happens. It's probably more extreme than what would happen during fermentation, but it might approximate a "worst case scenario" upper limit.

[brewinhard]

Bubbling CO2 through beer is a well known technique that can scrub aroma and flavors, so why not hops?  It may not reduce IBU but I'd bet it can remove some volatile compounds from dry hopping.  If your fermentation is almost done, it may not remove much in practice.

Good point. The question is how much it would actually remove in practice. I have an old keg of IPA I've been meaning to dump to make room for some new batches. Maybe I'll throw a couple of ounces of hops in the keg for a few days then go through some purge/degas cycles to see what happens. It's probably more extreme than what would happen during fermentation, but it might approximate a "worst case scenario" upper limit.

I would be curious as to the results on this.  Anyway, when I do dry hop in primary I always add a bit more hops just to account for any potential loss that might occur from this practice. I mean, come on, who wouldn't want another oz (or two) in their beer?

[HoosierBrew]

Just anecdotal, but since I like to brew hoppy beers there are lots of anecdotes. I've always felt that there is some scrubbing of aromas as the CO2 exits. I've noticed it in keg as well a few times when I overcarbed the keg and vented the PRV several times. Doesn't mean somebody couldn't add a few more hops to compensate. But since I started keg hopping (with the beer fairly clear) I couldn't be happier with the aromas. My $0.02  .

[westcoastbrew]

I always wait until fermentation has completed.  That way the CO2 does not carry the hop aroma out of the fermenter as it escapes and instead stays in contact with the beer.

I'm going to call BS on this as an old brewer's tale that just makes no sense to me whatsoever. If the hop oils are in solution, then there is little risk of CO2 in gas form removing it from the beer. Hop aroma compounds aren't some magical substance that evaporates rapidly at room temperature (after it is already dissolved in solution, mind you) if you look at it the wrong way.

As far as I understand, during the dry hopping process you are not extracting any significant amount of oils from the hops and instead are just taking some of the fragrance? In order to extract and isomerize oil from hops and imbue your beer with it, you need to reach a temperature of 175 F or so (at least for bittering purposes).  If that is true, it seems to me that a sealed environment or at least one that was not constantly being purged with CO2 would be better. It would be awesome to see some research on it as I am just speculating.