Late Hops and Myrcene Evaporation

Well, yes, obviously if you heat something volatile you will increase its rate of loss by evaporation. What I was trying to suggest - perhaps more ineptly than successfully - is that we shouldn't think that there is a temperature below which all will be fine, all of our hop oils will be retained. But that, exceed this temperature and then poof! - all of the oils will suddenly, instantaneously evaporate and their flavour/aroma will disappear completely from the wort.

Presumably, whilst temperature will drive off some of the volatiles, there will be other interactions in the wort (oxidation? polymerisation?) that will significantly affect the flavour and aroma of the final beer. This is why I was interested in first wort hopping & how it might work.

Hoppyland said:

Well, yes, obviously if you heat something volatile you will increase its rate of loss by evaporation. What I was trying to suggest - perhaps more ineptly than successfully - is that we shouldn't think that there is a temperature below which all will be fine, all of our hop oils will be retained. But that, exceed this temperature and then poof! - all of the oils will suddenly, instantaneously evaporate and their flavour/aroma will disappear completely from the wort.

Presumably, whilst temperature will drive off some of the volatiles, there will be other interactions in the wort (oxidation? polymerisation?) that will significantly affect the flavour and aroma of the final beer. This is why I was interested in first wort hopping & how it might work.

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The problem is that with volatile compounds the rate of loss will increase with temperature and this temperature may also cause breakage of the double bonds in which case the aromatic fragrant nature of the compounds is lost. The flavours will either be lost by evaporation or degraded by the excess energy into fragments that add nothing beneficial to the beer. Whatever the science is exactly this IS borne out by empirical observation by most brewers. Add early hops and lose the flavour but the bitterness remains.

I no longer add late hops to the boil as I used to. If a recipe calls for flame out hops, I allow the wort to cool to around 85degrees and put the hops straight in my cube then add the wort and leave to cool overnight.
My last batch (which I finished this afternoon) had the most pronounced peachy aroma of any of my previous brews. I've got another batch in a king keg and one in the FV, I just hope they turn out as good as the last one.

geetee said:

Add early hops and lose the flavour but the bitterness remains.

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So you think that First Wort Hopping is a myth then?
Can't speak either way as I've never tried it back-to-back.

Hoppyland said:

So you think that First Wort Hopping is a myth then?
Can't speak either way as I've never tried it back-to-back.

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Me neither but the vast majority of wisdom will say that hop oils will boil off from the early hops and it's just a waste of good hops. Most commercial brewers will only put bittering hops up front and keep the aroma/flavour for late.
I don't use 30, or 15 minutes hops and very rarely 10 minutes for the same reason and usually just add very late or steep.

If it works for you than that's great but for me lt's late all the way!

geetee said:

for me lt's late all the way!

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Ah, isn't brewing great! :)
All my beers have a bittering hop up front. Then late flavour hops at flame out & then dry for aroma. I don't chill.
But I'm still wondering about first wort hopping....... :-?

Hoppyland said:

Ah, isn't brewing great! :)
All my beers have a bittering hop up front. Then late flavour hops at flame out & then dry for aroma. I don't chill.
But I'm still wondering about first wort hopping....... :-?

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The longest boil i've ever done is 30 mins but I put more hops in for less time to get the same effect.

I'm trying the extract version of punk ipa 2007 next so will most likely bung all the hops in at flameout, into the fv seal it up tight and pitch the following day removing hops 5 days later. wish me luck :whistle:

dad_of_jon said:

The longest boil i've ever done is 30 mins but I put more hops in for less time to get the same effect.

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Just to be clear, D_o_J is a refusenik extract brewer and wont come over to the dark side, so can boil as little as 15 mins if he likes.

I'm tempted to get the forum thumbscrews out. Confess your extract wickedness heretic!

Hoppyland said:

No, I suspect that you haven't got this right. Myrcene, from what I've seen, has a boiling point of 167C.
Consider water, most definitely a vital component of beer. It melts at 0C. At any temperature above this it will evaporate provided that the atmosphere isn't 100% saturated with water vapour. Heat it to 100C and it will boil. But even when you boil your wort for 60 mins - most of the water is obviously still left behind. We don't worry about it all disappearing.

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Thinking about the process of distillation here. It doesn't take long for the alcohol to vanish out of the wash in a distillery when it is heated to 79C. Granted it doesn't vanish instantly, but why would it not be true of Myrcene which boiled off at 63.8C that it vanishes when heated to 100C?

The analogy between Myrcene and water doesn't work. Water in your analogy is beinbg held at exactly its evaporation point not well above it. The water can only reach its boiling point and no more, but the myrcene is being held at way above its boiling point for at least fifteen minutes in the case of a late hop 15 minute addition. If you put water on a thick steel plate heated to 150C it will evaporate instantly and violently. That is the situation that myrcene is in vis a vis evaporation when it is in a solution at 95.7C.

Tony1951 said:

Thinking about the process of distillation here. It doesn't take long for the alcohol to vanish out of the wash in a distillery when it is heated to 79C. Granted it doesn't vanish instantly, but why would it not be true of Myrcene which boiled off at 63.8C that it vanishes when heated to 100C?

The analogy between Myrcene and water doesn't work. Water in your analogy is beinbg held at exactly its evaporation point not well above it. The water can only reach its boiling point and no more, but the myrcene is being held at way above its boiling point for at least fifteen minutes in the case of a late hop 15 minute addition. If you put water on a thick steel plate heated to 150C it will evaporate instantly and violently.

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I'm entirely happy to accept, from those with more knowledge of physics than myself (and there must be many!), that the boiling point of myrcene might be a total irrelevance, and that my comparison with water (or indeed bacon!) is crass :)

However, I'm still confused as to what the boiling point of myrcene actually is (and, as my wife will readily confirm, I'm a pedantic old git! :-?)
So far I have:
Wikipedia - 166-168C
www.chemicalland21.com: 167C
http://www.chemspider.com/ : 167 °C (Oxford University Chemical Safety Data)
A quick scroll down the search results indicates a lot more of like mind.

I really do find all of this fascinating. Just as well, I guess - if I spent as much time drinking the product as thinking about things to try, I doubt if my liver would handle the strain :lol:

The puzzling thing about all this Hoppyland is that there is information out there on the web saying that myrcene evaporates at 63.8C and that it vanishes quickly when boiled. If I said it boiled at that temperature, I was obviously wrong. One thing for sure, it vanishes if it gets the chance. Look how dry hopped beers lose it between week two or three in the bottle and week ten.

I'd like to know more about this.

Tony1951 said:

myrcene ...evaporates at 63.8C .... vanishes quickly when boiled. .... it vanishes if it gets the chance. Look how dry hopped beers lose it between week two or three in the bottle and week ten.

I'd like to know more about this.

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I absolutely agree, Tony. It really is fascinating (and as a retired biologist, I do mean this in the most sincere spirit of enquiry!)

This is the real thing that I love about this forum. It offers a platform for honest opinions, experiences, and an exchange of differing views without rancour. We all seem to respect each other - nobody is preaching that their way is right and everyone else is a stupid ******.
Web forums are not my natural habitat. I only contribute regularly to this one. I sometimes chip in to an artist (painter's) site - I'm not good enough to say much there. I do regularly look into a forum regarding a football team (Newcastle, since that is my homeland).
The Artist's forum self-proclaims to be dying on it's feet. And it certainly does seem to have very few contributors - even fewer younger than 60. If you log in, you might find 2 or 3 threads updated in the last 24hrs. The last new thread on a particular topic might be a week ago. Some of the categories have a last posting of months. This is a website promoted by the publishers of 2 magazines - The Artist & Leisure Painter.
Are there more serious amateur brewers in the UK than amateur sketchers/painters? Apparently yes, manyfold - or at least ones willing to step forward & articulate their thought/questions.

As for the footy site, well the less said the better. There is some extremely good dry humour. There is also some remarkably ill-informed and bigoted comment. I have long stopped offering up any of my thoughts. To be frank, I don't know why I even look at all now. Rather like the Artist's site, the number of active contributors has fallen away in the last few years. As you might expect, the standard of contributions has therefore fallen (not true of the Artist's site, though).

Bottom line - what a valuable help to brewing this site is. I bet a lot of people hearing about a homebrew site might think: "Well, that's going to be ****. By the time they get round to saying anything at all, they'll probably be ******. Even if they're only half-******, they'll be tub-thumping. " My Way Is Best. Your Way Is ****.

How wonderful that the truth is the absolute opposite!!

MyQul said:

Just to be clear, D_o_J is a refusenik extract brewer and wont come over to the dark side, so can boil as little as 15 mins if he likes.

I'm tempted to get the forum thumbscrews out. Confess your extract wickedness heretic!

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guilty as charged m'lud :whistle:

and loving it :lol:

I do use some grains when i'm feeling a bit light-headed:drunk:

Hoppyland said:

I absolutely agree, Tony. It really is fascinating (and as a retired biologist, I do mean this in the most sincere spirit of enquiry!)

This is the real thing that I love about this forum. It offers a platform for honest opinions, experiences, and an exchange of differing views without rancour.

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I completely agree about the general tone on this site. Very refreshing in comparison to many others for sure. I have had huge amounts of help and information and met some very generous folk on here. I was / am also a member of a very good clock forum which has similar people very keen to help folk with their knowledge. I had incredible help there, including when a situation arose in which my very imperfect horological skills were not up to repairing an early twentieth century Swiss pocket watch which had a broken balance wheel, an offer from a retired watchmaker to take it in hand. He sent it back to me three weeks later completely repaired (including with a new balance wheel he had in some ancient drawer AND - he absolutely refused any payment at all, beyond the costs of sending it back. When I sent him some dosh for a few beers - he was offended sadly... As they say around these parts, 'There's nowt so queer as folk'. :)