Whirlpool hop additions? Please explain.

So I keep coming across references to adding hops to the "whirlpool" or at whirlpool. I am not clear on what this refers to. I have not been able to find the answer so I put it to you fine folks.

I use the "whirlpool technique" to seperate hops and trubs before racking to the fermenter. Is this the whirlpool that is meant? If so it does not make much sense to me. When I whirlpool it is after the wort has been cooled to around pitching temps with a chiller. I would think there would not be much extraction of anything from the hops at this point. Plus you just added more gunk to be avoided in transferring.

Is there a different whirlpool or am I missing something? If someone can explain not only the when but the why that would be great. Please straighten me out.

I'm not sure what it actually means, but when I do a whirlpool addition it is before I go to my chiller because I use a CFC. I've been doing that instead of a 0min addition to my kettle. I have no idea if it's made the brews better, but it didn't make any negative difference that I could see.

Was it a Jamil recipe? I think in his terminology, at whirlpool means at flame out or just before. If you use an IC cooler, it will work faster if the wort is in motion around it while cooling. Thus you start your whirlpool as soon as you turn the flame off and start the chilling and toss the hops in.

No, though I am sure I have heard him say it as well on the bn. I have seen it quite a few places.

I guess that makes sense. Technically that is sort of what I am doing. I use an ic and I have a lid with a stirring arm so I can keep it moving around the coils. I opften add hops right at flameout and then start stirring and the chiller.

In some professional brewhouses, the "whirlpool" is a large vat where the hot wort is separated from the trub by means of whirlpooling. It is still hot at this stage and will last approx. 1 hour. A hop addition would likely add bitterness and aroma. It would also be plenty of time for the newly added debris to settle.
I'm not sure if this is what you're talking about...

A commercial whirlpool is a tank that is arranged to spin out particles before cooling. Some breweries will use their whirlpool as a hopback, but others have a separate tank for that.

We get the same impact with a flameout add. Both give the wort additional nose.

I had thought perhaps it was refering to commercial brewing procedures. However I have heard and read homebrewers mentioning it. I think I get it now.

Thanks folks.

Right. Its a commercial Brewery procedure that last maybe an hour to remove particulates. So the real question is what is the homebrew approximation? Since we go straight to chill, I would guess dry hopping. I go through a reverse flow chiller, so I am cold in the carboy dang fast. To me it would seem a waste of hops.