Best practice for purging headspace during/after dry hop

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
That's a good technique. I'm planning on at least a tablespoon of spice. I'd also like to dry hop my IPAs with ground up hops (you know what I'm talking about :mug:), so I won't be able to continuously purge while adding those either.


I did think of a tincture, but I also wanted the ability to add powdered ingredients, so I was looking for a different overall solution. It also crossed my mind that non-IPAs could likely survive some oxygen, but I want my beer as high quality as possible and I'm willing to use some extra CO2 to get it.


Well, if it works, it works. This might be too nitpicky, but do you think that the 10 or so seconds of contact with oxygen would negatively affect the beer even if I purge the hell out of it after sealing?


Thanks guys! :mug:
It takes time for beer to absorb a significant amount of O2 from the headspace, so the shorter the exposure the better. You want to get the purges done as fast as you can, consistent with getting a complete pressurize and vent with each cycle. If you can't drop from a purged chamber, your proposed method is the second best option.

Brew on :mug:
 
It takes time for beer to absorb a significant amount of O2 from the headspace, so the shorter the exposure the better. You want to get the purges done as fast as you can, consistent with getting a complete pressurize and vent with each cycle. If you can't drop from a purged chamber, your proposed method is the second best option.

Brew on :mug:
Sounds good to me. Thanks!
 
Well, if it works, it works. This might be too nitpicky, but do you think that the 10 or so seconds of contact with oxygen would negatively affect the beer even if I purge the hell out of it after sealing?
I don't think so, my beers always stay un-oxidized for their lifetime (1-1.5 months) in the keg, and these are primarily NEIPA's which are prone to oxidation.

I purge probably way more than needed, but I'd rather do more than not enough. And once I pop the lid off of the keg, I have the CO2 flowing, so I like to think that CO2 is flowing out of the keg, reducing how much O2 can sneak in. Then once the keg is sealed again, I do at least 10 purges, some of which I allow the keg to pressurize before pulling the PRV, and some I just leave the PRV open to allow outward flow of CO2, and whatever O2 is in there.

Try and see what happens, and once you figure out what works, rinse and repeat.
 
Sorry to resurrect a somewhat old (but not yet ancient) thread. Regarding using fermentation CO2 to purge a dry hopper, should we not be concerned about the hops sitting in a relatively high O2 partial pressure environment until it's scrubbed? Do hops degrade less in the presence of O2 when they are physically dry? If not, then I don't see any benefit to leaving the hops sitting in a dry hopper slowly getting scrubbed vs dry hopping without a hopper before fermentation is done (same benefit of yeast scrubbing O2). I would hate to spend $200+ on putting together a dry hopper and then fail to leverage any real benefit from it.

The best option would of course be a series of true pump/purge cycles, but a vacuum pump is not a standard brewhouse item. A one-time investment to set up a nitrogen purge capability (N2 is much cheaper than CO2) would be another option. But I haven't done any legwork on costing this out and finding the break-even point.
 
Regarding using fermentation CO2 to purge a dry hopper, should we not be concerned about the hops sitting in a relatively high O2 partial pressure environment until it's scrubbed? Do hops degrade less in the presence of O2 when they are physically dry?
See posts 9, 18, 26. At least one member here says he gets excellent results, and I don't think he worries about keeping the hops dry. Also see #35 - a commercial brewery may also be using this approach. I don't dry hop very often, but I'll be using this method the next time I do.
 
Can't really answer that question without knowing what equipment is available.

What I plan to try, for my next big dry hop load, is to place the hops in a sanitized keg, purge the keg with fermentation CO2, and then closed transfer the beer to the keg with the dry hops. Can decant to another purged keg if limiting hop contact time is desired.

Another method is to drop the dry hops in from a purged chamber, but that requires special equipment.

Brew on :mug:
I was thinking of trying this as well. If it is under pressure then I don't have to be quite as concerned about temp either, right?
 
Back
Top