[jeffjm]

Are there any pros or cons to keeping a whirlpool going during the hop stand?

[HoosierBrew]

I've never bought a pump ( yet), so it's a moot point for me.  But breweries obviously whirlpool and, as I understand it, more bitterness and flavor is extracted more quickly by whirlpooling during this period.

[kramerog]

Are there any pros or cons to keeping a whirlpool going during the hop stand?

From the perspective of a homebrewer who doesn't have a pump and does hop stand in boil kettle

PROS:
-possibly better transfer of hop compounds into wort - remember in the boil the wort is being mixed by the boil; I feel this is somewhat of a minor advantage for homebrewers.  For commercial breweries, the extra efficiency could be beneficial.

CONS:
- hot side aeration (probably not an issue)
- difficult to keep a whirlpool going (occasional stirring might work just fine)

[Stevie]

Do you guys put the lid on the kettle during your hop stand?

I don't. I let my flame out hops steep for 10 minutes before chilling with the lid off. At the end of the 10 minutes, the wort is still 190+ so I don't worry.

[erockrph]

Erockrph...Are you adding the hopstand addn at flameout or are you cooling to a specific temp? I've been cooling to ~170 then adding. Not getting much discernable bitterness increase when I do that, though I expect it would test higher.

Personally, I think the higher temps help with extraction of hop flavor/aroma compounds. For most beers I do add my hop stand hops at flameout. I brew on a ceramic cooktop, so I kill the heat and slide the kettle off the burner. As soon as all boiling/bubbling has stopped I add my flameout hops and stir constantly for a few minutes until all the pellets have dispersed and all the hop material has become wet. Then I throw the lid back on and slide it back on the warm burner (now turned off) to keep the heat loss relatively slow. I'll come back and stir every 5 or 10 minutes.

For lower IBU beers, I'll let the temp drop down to about 180-185 before adding my hop stand hops. I find that 30 minutes at this temp is in the ballpark of 5 minutes more boil time. I brew 3 gallons in a 5-gallon kettle with a pretty thick-clad bottom. YMMV based on your system.

[HoosierBrew]

Actually, my hopstanding is a work in progress as far as having a set temp and time length.  I'm still experimenting. So far I've felt that cooling to under 190F has resulted in slightly less of the hop aroma being driven off and slightly better hop flavor but, again, it's an ongoing thing. I want to revisit adding at actual flameout again and working my way down below 170F or so over successive batches, as well as changing time increments.

[dolecek21]

Interesting. I've never tried waiting for the wort to drop to a specific temperature for a hop addition/hop stand. Typically I just add flameout addition and whirlpool (occasionally stir) anywhere from 5 - 20 min, depending on the beer. At what temperature do you start worrying about DMS?

Also, a couple people have mentioned studies/literature on hop stands. Does anyone have any links to anything that they have found particularly useful?

Thanks!

[kramerog]

At what temperature do you start worrying about DMS?

The question should be at what temperature do you stop worrying about DMS.  I forget the temperature below which DMS becomes a non-factor; perhaps ~180 F.  Bear in mind that a good 1-hour boil should eliminate DMS except for pilsener malts.   

[HoosierBrew]

Interesting. I've never tried waiting for the wort to drop to a specific temperature for a hop addition/hop stand. Typically I just add flameout addition and whirlpool (occasionally stir) anywhere from 5 - 20 min, depending on the beer. At what temperature do you start worrying about DMS?

Also, a couple people have mentioned studies/literature on hop stands. Does anyone have any links to anything that they have found particularly useful?

Thanks!

First, I've never had any DMS problems from doing a hop stand. There's a person or two here that hop stand longer than I typically do and have never reported any issues either. I believe that both Zymurgy and BYO have done articles in the last year on hop stands, but an internet search will give you lots of references on the subject.
 It really is one of those things to just try for yourself. I don't use a pump so I can only speak to my method in terms of flavor and aroma quantity. Doing a hop stand at flameout will definitely give you more bitterness than doing one at, say, 180F. I feel that the aroma and flavor is slightly better at < 190F, but that's just my observation.  Try and compare, take good notes, and you'll have your own data that's specific to your brewery. Good luck !