Late Hops and Myrcene Evaporation

[geetee]

Bigcol49

We should challenge All of the long held axioms of home brewing and many do. It's only by trying different things that we find what works but may also find that some are true. The good thing is you can usually drink all of them so nothing lost by experimenting.

 

[Bigcol49]

The good thing is you can usually drink all of them so nothing lost by experimenting.

Aye! It aal gans doon the clack :lol:

 

[Tony1951]

Tony, this is a really interesting article. If you look at the structure of Myrcene it is an 8 carbon chain and is in fact an octane molecule with the addition of 3 double bonds.
You know how volatile octane is and thank goodness for those extra bonds otherwise our beer would smell like petrol!

I'm glad you understood the molecular diagram (if that's what it was) because I don't. Well it shows how bad heat is for it though doesn't it. Probably why those flavours and aromas are quite elusive and disappear out of bottles kept too long.

 

[dad_of_jon]

There is plenty here to think about Dadof jon . One thing though - no chill and I have some bad history. I don't know what it was but I got some horrible brews while I was trying that. I know other people make a success of it, but I had gallons of 'orrible muck which I struggled to drink. I certainly didn't offer it to anyone else. Because I don't know why those brews went wrong, and because I have the cooler now, I'm not going back there. I'm like a half poisoned rat - I NEVER try again what made me ill, if you get my meaning.

Hi Tony, so in your circumstances you're not going to get additional bittering from an extended cooling period, so it would be cheap hops for bittering and aroma flavour once at pitching temp i'd suggest. (based on your original thoughts)

 

[Covrich]

Whilst I do, do it.. I don't think dry hopping lasts as long as adding hop stands or 5 min additions.. I wouldn't remove adding a late hop addition altogether because I am not sure that there isn't a diminishing effect and hops in hot wort do I think seem to hold falvours better..

Just my take on it

 

[Hops_and_Dreams]

I think this can be over worried about. If adding hops brought bacterial problems there would be no dry hopping at all because the beer would be ruined. Having said that, I might be a bit cocky about my lack of worry about bacteria. I clean my gear, I store it in a clean place and I rinse it again before use under a strong running tap. I slosh a bit of oxy what not around my FV and bottles before I use them, and then I rinse them in clean tap water which has chlorine in it at low levels to keep bacteria at bay. I never had a bacterial problem yet. (fingers crossed).

Sorry, I didn't explain very well. I meant if you cooled the wort to 65c, the added the hops, presumably you'd leave it for 30mins or so, in that time I wondered about any temp drop and a potential breeding ground.

 

[HisDudeness]

Pulls pin on grenade and walks away.......

http://brulosophy.com/2016/02/01/the-hop-stand-hot-vs-chilled-wort-exbeeriment-results/

 

[MyQul]

Pulls pin on grenade and walks away.......

http://brulosophy.com/2016/02/01/the-hop-stand-hot-vs-chilled-wort-exbeeriment-results/

As Brulosophy usually says, "this is only one data point". Puts grenade in dudes pocket and runs off

(tbh I've only scan read the results section. I just wanted to put a metaphorical explosive in dudes dressing gown pocket)

 

[Tony1951]

Pulls pin on grenade and walks away.......

http://brulosophy.com/2016/02/01/the-hop-stand-hot-vs-chilled-wort-exbeeriment-results/

Great find BUT - he held both conditions at 92C with the flame out hops for 23 minutes and then cooled one and not the other, so my contention is that the hop volatiles may well have evaporated off in that 23 minute hot steep. My contention was that since Myrcene evaporates at 63.8C I proposed that putting the late hops in wort above that temperature would be to risk losing it in steam. I don't think that article contradicts that hypothesis for obvious reasons.

By the way - you would have to increase the 60 minute hopping a bit to counteract the loss of isomerisation of alpha acids that would have occurred in the ten minute hops if they'd been used.

Cheers

 

[Brew_DD2]

It's good to read things like that. I'm experimenting with lower hop stand temperatures so I'll be interested to see if it makes any difference.

 

[HisDudeness]

As Brulosophy usually says, "this is only one data point". Puts grenade in dudes pocket and runs off

(tbh I've only scan read the results section. I just wanted to put a metaphorical explosive in dudes dressing gown pocket)

:lol: Just stirring the pot! Interesting results though....

 

[MyQul]

:lol: Just stirring the pot! Interesting results though....

Definately. I'll post my experiments with leaving the hops in the FV for the time of fermentation tommorow, to throw that in the mix too (I've drank too much HB to type a long and detailed post now )

 

[HisDudeness]

Great find BUT - he held both conditions at 92C with the flame out hops for 23 minutes and then cooled one and not the other, so my contention is that the hop volatiles may well have evaporated off in that 23 minute hot steep. My contention was that since Myrcene evaporates at 63.8C I proposed that putting the late hops in wort above that temperature would be to risk losing it in steam. I don't think that article contradicts that hypothesis for obvious reasons.

By the way - you would have to increase the 60 minute hopping a bit to counteract the loss of isomerisation of alpha acids that would have occurred in the ten minute hops if they'd been used.

Cheers

I agree the temperature difference means its not necessarily relevant to your idea Tony but the way I read it he added one batch of FO hops immediately to the wort but cooled the other batch to 78c before adding the FO hops. As he says himself at the end though this could still support the theory that hop stand temperatures should be even lower for a more noticeable effect which is what you're getting at originally

 

[Tony1951]

I agree the temperature difference means its not necessarily relevant to your idea Tony but the way I read it he added one batch of FO hops immediately to the wort but cooled the other batch to 78c before adding the FO hops. As he says himself at the end though this could still support the theory that hop stand temperatures should be even lower for a more noticeable effect which is what you're getting at originally

Gotcha Dudeness - I love experimenting. Sometimes it works and sometimes it doesn't. Of course, you have to have an idea that is in with a chance in the first place.

Hypothesis for next brew:

Fruity flavours from Myrcene will be enhanced by adding late hops to wort at not more than 63C then cooling after thirty minute steep to 20C.

Null hypothesis:

There will be no difference and any apparent difference will be due to chance.


Problems with this ? Loads:

1. An experiment needs two conditions done side by side like the Bruphiliosophy approach (one with late hops boiled and added at zero minutes at 100c and one done in the proposed way. I don't have the time, capacity or inclination to do the thing that way.

2. I can't test the null hypothesis because there is no way to evaluate the outcome except what I say about how it tastes.

3. My impressions will be valueless because I have a habit of boasting about all my beer however rubbish it is. This is due to impaired judgement of the sort shown below.

cheers

 

[geetee]

Tony

Spoken like a true scientist mate but also trust your judgement, remember they will both be your beers so your can make a proper judgement about which is best and /or just different.

 

[Hoppyland]

While I was reading about this elusive Myrcene oil, I discovered that it is an aromatic hydrocarbon, I noticed that it evaporates at above 64C. This suggests to me that putting in sixty grammes of expensive American hops at ten or fifteen minutes before turning off and cooling the wort is a waste of time, because you are boiling the oil away for at least twenty minutes..... Have I got this right?

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.

 

[Bigcol49]

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.

Myrcene has a boil point of 63.9C and water is not an aromatic.

 

[IainM]

I'm don't think the boiling point is a particularly useful figure to be concentrating on. We aren't boiling pure myrcene here, and regarding its extraction there are a number of factors. There is the stability of its form in the hops, which you could get an idea about by looking at its vapour pressure. Then there is its stability in aqueous solution, which is an approximation of what wort is, which we can get an idea about by looking at its solubility. Then there is the added complication of interactions with other molecular constituents of wort, which isn't at all clear. Then there are all the kinetic factors at play, such as the agitation of the wort, whether the hops are pellets or whole leaf. Really, considering all this, I can't see how the boiling point of pure myrcene has much to do with with the process of maximising its extraction in the wort and minimising its escape.

 

[Hoppyland]

Myrcene has a boil point of 63.9C

not according to this:
https://en.wikipedia.org/wiki/Myrcene
Is it wrong?

Maybe the boiling point is indeed an irrelevance - but I still wonder if we worry too much about hop oils - as if they will suddenly and completely vanish above a particular temperature.
This might be a poor analogy, but when I fry bacon I'm inclined to think "Yum, this smells great - can't wait too eat it". I'm not likely to think "Bugger, I've heated the bacon too much. Now, all the volatiles will be gone & it'll be tasteless" :-(.

Perhaps more pertinent is First Wort Hopping, which I believe is widely held to contribute to a pleasant, smooth hop aroma. If so, the aromatic compounds would have to survive both the entire boil and the whole fermentation.
Any thoughts??

 

[geetee]

Hoppyland says
"Maybe the boiling point is indeed an irrelevance - but I still wonder if we worry too much about hop oils - as if they will suddenly and completely vanish above a particular temperature."

From empirical evidence if you do boil hops the oils do disappear, that is exactly what happens and the higher the temperature the more fractions of the oils will reach the energy to break the bonds (escape velocity) and will be lost!

It is probably hard to define the exact point but I would reckon this works as a general principle as we all know to our cost, the higher the temp the more flavour will be lost.