HOP STANDING

Hop Standing

A hop stand is something I’ve been doing since I first met Luke Nicholas of Epic Brewing in New Zealand. He has been making and still makes some of the best beers in New Zealand for one very good reason, he went to the US and learnt from the top brewers over there. I remember it was one fairly boozy night in 2008 at the Malthouse in Wellington I think I was drinking either Epic Armageddon or Epic Mayhem and I was amazed at the aroma and amazed at the flavour….how could I brew beer like this, everything I was reading told me that I was doing things right…I should have better beer? So I asked Luke and he very kindly divulged his knowledge on the subject.

It turns out that what the Americans and Luke were doing was loading their hop additions at the end of the boil ignoring traditional brewing techniques. What this means is that you don’t work out your ibu’s and your boil hop amounts first, you do that last. The first thing you do is work out how many grams per litre (g/l) aroma and flavour hops the beer requires. This can be anywhere between 2-10g/l or more. A nice starting point for low gravity beers is 5g/l from this you can work out what the bitterness contribution to the beer is.

Alpha acids will continue to isomerize after flameout until the temperature of the wort reaches about 79 °C. Homebrewers trying to calculate a beer’s IBUs will need to guesstimate how much isomerization is occurring. The closer the wort is to 100 °C the higher the alpha acid isomerization rate. To do this, we can look to professional brewers for some guidelines. Ultimately, however, the thermal capacity of a professional 60bbl whirlpool vessel is quite different than 20 L of homebrew, so the comparisons can only be rough guidelines at best.

From my own experience with extended hop stands in 5-gallon (20-L) batches to 10bbl, a 3-5% utilization rate for whirlpool hops seems reasonable.

Wort Density 1.032-50 1.050-64 1.064-72 1.072-82 1.082-92
Boil time Utilization %
90 31% 28% 27% 26% 24%
60 28% 26% 24% 23% 21%
30 15% 14% 13% 13% 12%
15 8% 8% 7% 7% 7%
5 5% 5% 5% 4% 4%
0 5% 4% 4% 4% 3%

So instead of the traditional additions at 30, 15, 7, 5 and 1 minutes all the hops are added at the end of the boil, what I call a hop stand.

This allows the hops added at flameout a period to release their essential oils into the wort, while minimizing the vaporization of these essential oils, adding a kick of hop flavor and aroma as well as what can best be described as a smooth bitterness.

At wort boiling temperatures, ALL hop essential oils have surpassed their flashpoints, so a vigorous boil will drive them off fairly quickly. The best way to think about the driving off process is in terms of half-lives. The lower the flashpoint, the faster the oil vaporizes and the faster the half-life. The longer the hops are boiled and the lower the flashpoint, the less the essential oil will impact the beer. In effect, hopstand hopping removes the rolling boil (for the hopstand hops), lowering the temperature of the wort and therefore reducing the vaporization rate of the essential oils, allowing the essential oils to really “soak in” to the wort. The specifics of the “soak in” process is still very much a grey area but the idea is that essential oils will be retained in the beer longer and enhance the hop flavor and aroma of the finished beer.

A hop stand is simply allowing the boiled wort an extended contact period with the flameout hops prior to chilling the wort. Pro brewers typically create a whirlpool either in their kettle or in a separate whirlpool vessel with the hot wort and the ensuing vortex creates a cone shaped pile in the center of the vessel made up of the unwanted trub and left over hop material. Whether on purpose or inadvertently, pro brewers were giving their flameout hops extended contact time with the wort. This allows the hops added at flameout a period to release their essential oils into the wort, while minimizing the vaporization of these essential oils. In essence, adding a kick of hop flavor and aroma while also adding what can best be described as a smooth bitterness. In short, whirlpool hopping can add significantly to the hop flavor and aroma of beer.

The second factor to consider is the length of your hop stand. There are no right or wrong answers, but anywhere from 10 minutes to 90 minutes can be employed. I worry a little about leaving my hops to stand for too long, I don’t want DMS reforming so as a rule I hop stand for thirty minutes, giving the hops a good stir after ten.

Try it when you’re next brewing and see the impact it has on your beer, let us know how you get on in the comments below.

Formerly of Fullers, Thornbridge and Buxton. Now a freelance Black IPA advocate, homebrew geezer and creator of Baby Back Bacon Black IPA™

16 Comments

  • Reply September 4, 2014

    Daniel

    Have you ever experimented with steeping/whirlpooling below 79°C? This seems to be quite popular amongst some homebrewers, but would be interested to hear your take on it.

    I assume you’d get very little bitterness and thus require another addition during the boil, but in exchange for getting more aroma from the hop stand?

    Although I’d be worried of losing that different bitterness you can acquire from late hops.

    Great website, thanks again!

    • Reply September 4, 2014

      James Kemp

      Hi Daniel,
      I’ve heard that some people like to do that but I’ve not done it so far for a few reasons.
      1. Isomerization doesn’t occur under 80oC so any smooth bitterness from the end of boil hops isn’t garnered therefore you’d need to increase your start of the boil addition.
      2. Increasing your start of the boil addition adds more hop load to the boil increasing wort losses.
      3. I can’t find anything but anecdotal evidence that it’s better, I’d want to do some experiments before committing to it.
      4. Time and money, it takes a whole lot more time to do it and it costs more money because you’re essentially ruling out any bitterness that can be taken from the end of boil addition. This is probably only important in a commercial setting but it’s worth bringing up.
      I think it’s well worth experimenting with though, I’ll brew two identical beers, one with a standard hopstand, one at 80 degrees and see which has better aroma and let you know on here.

      JK

      • Reply September 6, 2014

        Daniel

        I look forward to it, should be a really interesting post.

        Brewed up a ~4% APA with 7g/L Mosaic/Moteuka today and tried out the technique with a 30 minute hop stand. Looking forward to seeing how the aroma and taste comes out versus my similar beers with late additions.

  • Reply September 8, 2014

    Kev

    Been hearing lots about techniques which sound like this for a while. Thanks for breaking it down so clearly… you’ve convinced me to give it a go with the IPA that I’m brewing tonight.

    Will go for an addition of around 10g/l at flameout, with a 30m stand. No other hops. Will report back!

    Thanks for the info. Cheers!

  • Reply September 21, 2014

    pdtnc

    Its a bit of a reminder this, I always used to do this but more recently I have been chucking a load in at the 5min mark (Rather like we do at Saltaire) with a minimal bittering addition at the start. I tried doing end of boil stands at Saltaire but its a fecker of a job stirring in a load of hops through the manway of a steaming hot 20bbl copper with no means to whirlpool.
    The http://www.WishboneBrewery.co.uk brewkit will have the means to Whirlpool the copper so the plan has always been to have a whirlpool addition.

  • […] Alpha) @ 60 Minutes (First Wort) (0.1 g/L) 44.0 g Ahtanum Leaf (4.5% Alpha) @ 0 Minutes (Flameout Stand) (2.2 g/L) (Software calculated as 5min boil) 44.0 g Columbus Leaf (16.5% Alpha) @ 0 Minutes […]

  • Reply October 21, 2014

    ChrisR

    I have been tending towards more later hops than earlier in my home brewing for a while now. I think it does indeed make a better tasting beer. I’ve not got as far as all hops being ‘standing’, though.

    But I have a question arising, which has puzzled me since I first read about the benefits of ‘late hopping’: say if, as you propose, ALL the hops went in the copper at flameout, then why do you need to bother with a 60 minute+ boil? Why not just boil for 5-10 minutes? And save all that energy/cost?

    I do know some beers need the caramelisation of a good boil, but surely the paler brews don’t?

  • Reply October 22, 2014

    JK

    Hi Chris,

    Good question and would be true if that was all the boil achieved, the function of the wort boil is not just for hop isomerization though.
    I’ll just give you a brief overview of some of the functions but I suggest a bit of research into them for a fuller understanding.

    • Sterilization of wort. Brewing raw materials are infected by microorganisms and must be heat inactivated

    • Halting enzyme action. Continual action of enzymes after normal mashing programme will affect the wort composition, enzymes need to be heat inactivated.

    • Removal of volatiles. During the evaporation stage of the boil, undesirable volatile compounds are driven off with the steam, for example dimethyl sulphide.

    • Reducing wort pH. Control of pH throughout the brewing process is crucial, the boil continues to lower the pH which is crucial for protein coagulation, VDK reduction etc

    • Reduces wort Nitrogen levels. It is crucial to lower the level of high molecular weight nitrogen so that it doesn’t affect pH and colloidal stability.

    • Precipitation of polyphenols and tannins. Proteins that combine with unoxidised polyphenols create chill haze, sufficient boiling precipitates them out into hot break

    • Producing reducing compounds. An important compound that delays the onset of stale flavours and production of oxidised chemical hazes, reducing compounds are formed during wort boiling.

    Hope that helps.

  • Reply October 22, 2014

    ChrisR

    Thanks for your comprehensive reply. I was aware of most of those, but wouldn’t most/all of those objectives be achieved with less than 60mins boil?

    Or to come at from a different angle; what’s the minimum boil time to achieve all the things you list?

  • Reply October 23, 2014

    JK

    Hi Chris,

    Some of those would but others would not, 60 minutes seems to be the shortest amount of time (without increasing the pressure) to achieve most of those ends, DMS reduction will require a longer boil but that depends on the malt and the fermentation.

    A nice example is this taken from Reed, R.J.R., Ferment, 1(6), 39, (1988)

    “During the wort boiling process, thermal denaturation causes coagulation of
    protein to form hot break. Efficient coagulation is favoured by a high wort pH, the
    presence of sufficient protein, and good wort boiling conditions, i.e. a minimum of 100oC, of sufficient duration (minimum one hour) and vigour (a good rolling boil).”

    Cheers

    JK

  • Reply October 24, 2014

    ChrisR

    Thanks for all the info..

  • Reply December 29, 2014

    John

    I’ve learn this method mainly from Jim’s homebrewing forum, and this was in a way a compromise for most of us who do not have a hopback.

    I myself chill the wort to 80c before adding the whirlpool hops, because I want to make sure that I only get the aroma and not have it isomerise and screw with my bitterness. I guess it’s something we get to do at homebrew level, as it’s impossible to cool a commercial batch down that quick at all. Unless, you employ the hopback method which immediately chills the wort.

    In fact, I was reading some post where they say it’s even better at 50c.. But I’m not too sure about it

    I guess it safe to do it on a homebrew level, and not add any 5/10/15 mins addition, and add it all at knock out and whirlpool it for 15mins, and factoring in the same ibu of what 15mins will give you. I rather work on max possible IBU rather than guesstimate on it, cuz can you really tell a 5 ibu difference?

    I too do work backwards on my bitterness, and add what ever I need at 60mins just to hit the target ibu.

    Great blog, looking to glean more

  • Reply December 30, 2014

    JK

    Hi John,

    Cheers for your comment, good point about whether or not 5ibu is noticeable, I did an experiment on that and found that it is and it has greater impact at lower abv’s.

    I really must do that experiment on the difference between two beers, one with whirlpool hops at 80 and one at 100. I’m a bit thrifty so I like aroma and flavour hops in at 100 because it means I spend less on bittering hops and I get less kettle losses. I’ll try and schedule it in soon.

    Cheers

    Jk

  • […] with a hint of something a little dark and suspicious… just how I think Citra should be. Hopstand technique working well […]

  • Reply July 1, 2015

    andrea93

    hi!
    when you deicide to use this technique, do you avoid 15/10/5 min addition or are they necessary anyway?

    • Reply July 3, 2015

      James Kemp

      Hi Andrea,

      When using a hopstand the key is that the 15/10/5 etc… minute editions are ALL moved to a 0 minute edition. Instead of working out different utilisation percentages for each edition, just use a 3% utilisation percentage for the whole end of boil edition to get your bitterness where you want it to be. This is a much better utilisation of your hops and will give you a much better aroma and flavour than several smaller additions throughout the boil. Hope this helps.

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