Whirlpool hopping confusion?

The big boys have hundreds of gallons of wort with all those hops in contact at high temps, then they pump the wort through a chiller into the fermentor. So yes, they start chilling right away but the wort is still hot in the kettle or whirlpool vessel above 170*F for almost an hour in contact with the hops as it takes a long time to move all that wort out and through the chiller. To mimic this, homebrewers allow the hops to stand for a period of time after FO before chilling.

 

It's a varied process from brewer to breweries.

Think of it as hot side dry hopping, really.

Some will chill down, add the hops right at flame out, and more while the chilling takes place. Some chill down to a certain temp, hold it, whirlpool hot with the hops and then continue to ramp it down.

The longer it stays hot, the more oils you get, and the more bitterness you can get. On the FW idea, they are doing REALLY large batches, which will take a while to chill down anyways, so they will get a ton more from a whirlpool than you will with a 6 gallon batch in a small kettle. It's a hopstand in the name of the fact they can't rapid chill it too fast an the hops still contact rather hot/warm wort for longer.

I've stopped doing a bunch of hopstands, like you, it's not the brightness you expect. I think it's mainly a function of several things, but I find that I'll dump it all at flame out, chill and add some more while whirlpooling and chilling it all the same. I'm not delaying my chilling, but using an immersion chiller, I'm not taking it from 212-60 in a matter of minutes, it's like 20-25 minutes rather, so I'm getting a good soak on the hops.

I'm about to get a hopback and do it all that way. Filter and infuse on the way back to the kettle to cool down, as well as giving it another pass in the hopback on the way to the fermenter.

Sometimes it's hard to realize that MORE hops, don't mean BRIGHTER flavors. It'll all muddle up and taste like hop juice. I do co2 extract to bitter, maybe a 10 min addition, and then dump all late. I've got pretty decent IPA's doing that, and no real muddled mess.

 

From Mitch Steele (Stone Brewing), paraphrasing: Flavor and finishing hops get 90 minutes of contact time with 200F wort . . . 15 minutes of whirlpool, 15 minutes of rest, 60 minutes to knock out of the brew kettle. He also advocates a drier beer to emphasize the hops.

My setup is different than Stone, but my late additions go in at 200F and it rips for 15 minutes. Temp usually drops to the 180'ish range then I start circulating through the chiller. It normally takes another 20 minutes to get it down below 70F where the hops are removed. Overall I have been pleased with this.

To the best of my knowledge, the science of hop-oil-absorption is incomplete. My idea is to copy someone (Stone) that does a good job. I also borrow some of the published techniques from RR regarding dry hopping (extended time/multiple additions) as I feel this is equally important. Finally, your water chemistry should not be ignored. Vikeman publishes a pretty decent IPA water profile in Brewcipher. How did we brew before the internet?

 

I take my kettle off the flame and put it in the sink with just cold water hitting the side of it. The kettle is cooled to 180-175 in just a few minutes. All of my hops for flavor go in at that time. The hop oils wont isomerize and become bitter in wort temps under 180. Once I have the hops in the wort at 175 or so I put the lid on and let it sit for an hour. The wort is about 150 an hour later then the hops are removed... Lots of good hop flavor in there. There are several different ways to do it and breweries have their own way of going about it.. we obviously dont have that type of equipment but I find my way to work quite well. If you dont add any bitterning hops to the boil you could certainly add all of your hops at flame out to get bitterness and flavor as the hops steep in the hot wort.. no telling the exact IBU but you could ball park it with software as far as utilization goes...

 

I love my hopback so far. Used it twice, the first time with 1 oz each of Citra and Centennial for a pale ale. The second time for an IPA with 1 oz each Citra, Amarillo, and Simcoe. Both beers had the best aroma of any I've ever done.

 

The reason for that is that there are at least two major things going on during the hopstand.

1) Flavor/aroma compounds are being extracted from the hops
2) These Compounds are escaping to the atmosphere

Each of these things is happening at different rates. These rates are temeperature sensitive, probably in different ways (rate of rate change) from each other. And the rates are different for different flavor/aroma compounds. And there are many different flavor aroma compounds.

To my knowledge, nobody has really modeled this. But with so many variables, it's no wonder that recommendations (based on individuals' experience (within their own processes) and preferences) vary.

 

Haphazardly. Usually involving a dart board.

 

Hops in hot wort causes the release of volatile compounds that contribute to flavor, but mostly aroma. Dry hopping doesn't add heat so it doesn't drive off those volatile compounds as rapidly, but it also may not "liberate" them all. I use a hop back in front of my chiller. The theory is that the hot wort strips the volatile compounds and then the chiller condenses them into the wort instead of allowing them to blow away in the breeze. It seems to work very well. I assume I still lose much of these volitiles during fermentation, buy I do notice a real flavor difference when I use my hop rocket.

 

i'd suggest going back to one of the original studies on the topic by Van Havig, formerly brewmaster of one of the Rock Bottom breweries. Here is a great summary of the study:
http://republicbrewpub.blogspot.com/2009/06/hopping-methods.html
One thing of note is that hop flavors were greater in the beers with an 80minute post FO contact time versus a 50minute (but that is in a vessel with a bigger volume to surface area ratio than our kettles i believe). But basic gist is that once off boil, hop oils are going to be retained in your beer much longer than during a boil. So don't be afraid to give some extended contact time between flameout and knockout. Hop stands works at 205 or 170F. Many homebrewers now prefer the 170F or below whirlpool addition. I still do an addition just off boil and am very happy with those results. I'll do a second addition at 175F if i'm going for a very hop forward beer. With that said, I'm sure Bryndilson is adding his hops at knockout (post-whirlpool) for a reason...but it still means the hops have a long contact time with the wort while the wort is moving through the chiller.
(i'm not positive, but think that hop-bursting article you're referencing on Mr Malty was written in '05. A lot has changed in this arena since then and i bet Jamil would have a slightly different opinion on the subject if asked about it now...but i wouldn't want to put words in his mouth so i will digress)

 

I'm throwing this in because I've tried different hop additions and have been disappointed like you in finding a big hop flavor that I'm looking for.

I did an experiment a few weeks ago. brewed two identical batches the same day. both 9% abv 2 row only malt.
1st batch
3 oz. summit hops for 60 minutes
1 oz summit + 1 oz Columbus at flameout
then I let it cool by itself outdoors with the lid off
1 oz summit + 1 oz Columbus at 190 Degrees was added and it took 15 minutes to cool to 175 degrees
then 1 oz summit + 1 oz Columbus at 175 degrees. let it sit for 30 minutes then started cooling.

The 2nd batch the only change I made was instead of adding hops at 190 degrees & 175 degrees, I instead added them at 170 degrees and 140 degrees.

The 2nd batch that had the hops added at the lower temperatures had a much more pronounced hop flavor with some aroma. The hop flavor was earthy and full and a bit grassy. I'd definitely do this method again, but it was a bit one dimensional and I would next time add some late addition hops just before flameout to round things out a bit more.

The 1st batch that had the hops added at 190 & 175 degrees was missing a lot of hop flavor, mostly just the bittering hops came through, and there was no aroma. Since both batches had hops added around 170-175 degrees, and were allowed to rest, I'm figuring that the 2nd batch where I enjoyed the hop flavor got most of that flavor from the 140 degree addition.

 

How long are you steeping each addition on average? Is it the 80 minutes you cited above? Do you have any idea what the "optimal" contact time would be for different temperatures?

 

i have my own "optimal", i typically keep whirlpool going for about 20 minutes for standard hop forward beers then let it settle for 10 minutes before chilling. Chilling takes maybe 5-10 minutes for 11 gallons. Non hop-forward beers just get 5 minute whirlpool and 10 minutes settle time. More hop forward beers get 30 minutes whirlpool, 2nd addition of whirlpool hops at 175F and whirlpool another 10 minutes, settle for 10 minutes and chill.

I tried the last technique (two-stage whirlpool) vs. just dropping the beer to 175F before adding whirlpool hops, then whirlpooling for 20 minutes followed by 10 min spin down (same amount of total hops in whirlpool) and in taste tests the two stage won. (kind of unfortunately one is 45 minutes while the 2nd was 30 minutes so it wasn't the best test). Anyway that is the technique i stick with for my iipa and aggressive ipas for now.

I haven't done too much testing with this, so it's pretty much just the way I've started doing it and the way I'll keep doing it until something new convinces me to change...like hopfenundmaltz tells me differently.

 

"time between flameout and knockout"

I guess the definitions have changed, but those terms used to be used synonymously.

 

don't think the definitions have changed, just distinctions are started to be made among homebrewers. Homebrewers used to start chilling as soon as they turned off the heat so they could be used synonymously...now there is often a lapse like in a pro brewery...actually it was something I needed to look up about 6 months ago. My only guess is knockout refers to the fact that cold trub is knocked out of the wort during chilling...(?)

 

Great article here from the brewer at Kent Falls Brewing:

http://www.bear-flavored.com/2013/07/the-benefits-of-hop-stand-whirlpool.html

 

We have a 3 Barrel system, (100 gallons) so I'll explain what we do with that.
After the boil we do a whirlpool at flame out. We will let that settle a bit and let the sediment settle to the middle. We will then pump the hot wort through a 20 gallon container filled with hops. After it passes through that, it hits the chiller plate and then we pump oxygen into it as it's filling up the ferment container.