Dry hopping: Primary vs. secondary

I like to pour my new wort over last batches yeast cake cause I'm cheap n lazy, so I'm currently cold crashing my primary. I plan on brew day to rack my primary onto hops for a week or two and just dump my new wort on 1/3 of the left over yeast cake/trub in the primary & repeat in a few weeks


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Bensiff said:

Advantage of primary is you didn't waste your time and risk of oxygenation and infection by using a secondary. I'd only consider a secondary if I wasn't going to keg the beer (I dry hop most beers in the keg) and I wanted to keep the yeast. Another thought is that IIRC it is ideal to dry hop right at the tail end of fermentation so the CO2 can scrub out any introduced oxygen or something like that, so dry hopping in the keg like I do is not necessarily the best thing, just works for me being lazy.

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If you're dryhopping in the keg, you can sanitize your keg, put the dryhops in, seal it up and flush it with C02. This will get rid of any introduced oxygen that came along with the hops. Rack on top of them (and under the C02, which is heavy and will hang around in the keg when you re-open the lid for racking.

Another technique that I've seen, but not yet tried, is to rack it through the liquid out post with the lid closed but the relieve valve unscrewed just enough so the gas displaced by the beer can escape as the keg fills up.

STLExpat said:

Tossed the hops in a few days ago. Still smells ok, but is it supposed to look like this?

View attachment 64251

Didn't cold crash it before hand due to lack of fridge space

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Yes. That's healthy beer.

BigJay13 said:

This isn't a great idea because the co2 will drive off the aromatics of the hops. Not to mention hop oils will coat the yeast cell walls making it difficult for them to get things in/out of the cell. Just throw in the dry hops after fermentation has stopped.

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I'm not convinced there's any proof or science behind what you just said. I've heard the c02 driving off aromatics a bunch, but I don't really buy that. The aromatics come from the oils, and the oils aren't getting driven off by C02 bubbling through an airlock, merely gases.

The other thing...well I'm not saying you're wrong...and maybe I am misinformed...but I've never heard or read any such thing. There's far more hop oils in the wort by what happened in the boil kettle then there are introduced by a dryhop addition, and I've never noticed yeast being more fickel, petering out, or difficult to manage in hoppy vs. non-hoppy beers.

jbaysurfer said:

I'm not convinced there's any proof or science behind what you just said. I've heard the c02 driving off aromatics a bunch, but I don't really buy that. The aromatics come from the oils, and the oils aren't getting driven off by C02 bubbling through an airlock, merely gases.

The other thing...well I'm not saying you're wrong...and maybe I am misinformed...but I've never heard or read any such thing. There's far more hop oils in the wort by what happened in the boil kettle then there are introduced by a dryhop addition, and I've never noticed yeast being more fickel, petering out, or difficult to manage in hoppy vs. non-hoppy beers.

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My first technical post relating to brewing but I think I am ready lol. Might as well resurrect an old (yet still interesting) thread in the process.

After a bit of research, I found this article that explains essential oil volatility.

http://craftbeeracademy.com/the-science-behind-hops-part-2-essential-oils/

To paraphrase:

"The major essential oils we are talking about here are:
Myrcene
Humulene
Caryophyllene

All three essential oils listed here are very volatile in air, which means they disperse themselves easily into air. This is what happens when you smell the aroma of anything, especially beer. You are smelling the volatile compounds breaking down. For this reason, Myrcene is actually used in the perfume industry to help as an intermediary in perfume aromas."

Basically, it is not the Oxygen vs CO2 aspect of waiting to dry hop until after fermentation tapers off, it is the cycling of gas (CO2 or oxygen) out of the fermenter through the airlock that will essentially "carry away" some of the aromatic properties that the beer would have.

Due to the hihgly volatile nature of these three compounds, they disperse very easily into the air and if dry hops are added in the beginning, because gases are leaving the fermenter at a much faster rate than later on, more essential oil aromas are being carried away due to their highly volatile nature in air (CO2 or normal air)

FWIW

Flyboyknight:
That's a great post. Thanks for sharing your research. It doesn't address my second concern (quoted) but it certainly addresses my first question. It seems to me that it creates solid reasoning behind dryhopping in the keg so that the aromatic gases can be driven back into solution while force carbing. Would you agree with that?

Also for BigJay: I stand corrected!

jbaysurfer said:

Flyboyknight:
That's a great post. Thanks for sharing your research. It doesn't address my second concern (quoted) but it certainly addresses my first question. It seems to me that it creates solid reasoning behind dryhopping in the keg so that the aromatic gases can be driven back into solution while force carbing. Would you agree with that?

Also for BigJay: I stand corrected!

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So my laziness pays off, and my IPAs go so fast oxygenation doesn't have a chance to impact things. As for as the hop oil coating the yeast cells, I have never heard of it causing problems during fermentation. I have read that the issue comes with subsequent generations if you choose to repitch the yeast. But right now I'm not in the mood to track a source down on that so maybe someone else will.

Google brulosopher he does an experiment where he dry hops one beer in primary and the other in secondary it should give you a pretty good idea of the results.


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