'Driving off' hop oils

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Meatymc
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'Driving off' hop oils

Post by Meatymc » Tue Feb 12, 2019 5:04 pm

Can anyone tell me whether hop oils effectively evaporate in the boil or morph into a totally different 'compound'? I'm looking at trying out late hoping for more punch but due to equipment and location restrictions have to use the no-chill method (I'm also a BIABer but can't see that makes any difference in this scenario).

If they evaporate I'm guessing that even though it takes hours for the wort to cool sufficiently in the sealed container, transfering the wort immediatley after the end of the boil will trap in the oils - if they 'convert' I'm wasting my time (and money).

Robwalkeragain
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Re: 'Driving off' hop oils

Post by Robwalkeragain » Tue Feb 12, 2019 9:52 pm

They break down into other substances and the mechanical action of boiling will drive off aromas. Sealing doesn’t work, myrcene has a low flash point.

Just dry hop, it’s easier and makes the most of aroma compounds!

Meatymc
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Re: 'Driving off' hop oils

Post by Meatymc » Tue Feb 12, 2019 10:33 pm

Robwalkeragain wrote:
Tue Feb 12, 2019 9:52 pm
They break down into other substances and the mechanical action of boiling will drive off aromas. Sealing doesn’t work, myrcene has a low flash point.

Just dry hop, it’s easier and makes the most of aroma compounds!
Cheers Rob

Does that apply if added only in the last 15 minutes of the boil? And what about placing the hops in the container and leaving the boiled wort for 15 minutes to cool slightly before pouring it in?

Have been dry hoping for the last few brews but not getting the results I'm after - even when I've used purchased hops of a known aa% rather than my own home grown which of course are a bit of an unknown.

Meatymc
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Re: 'Driving off' hop oils

Post by Meatymc » Wed Feb 13, 2019 1:54 pm

I've been doing a bit more reseach on this and although I couldn't find any experimental evidence involving no-chill there's plenty out there comparing late hopping to hop stands (which is probably as close to my no-chill query as I'll get) to dry hopping.

There's the usual wide variance of opinion but for those like me, looking for hop soup, late wins hands down over a more tradional hop schedule and dry hopping very much better than a hop stand. So I guess it's a minimal addition for bitterness at the start of the boil, a good dollop in the last 15 minutes and a shed-load when near target gravity in the fermenter. Brew day on Friday :D

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Re: 'Driving off' hop oils

Post by Robwalkeragain » Wed Feb 13, 2019 6:11 pm

It’s the long exposure to heat that will break down the aromas, hops added in the cube won’t add much aroma if the wort is hot.
There are other options - one is to reserve a portion of wort - a gallon or so - steep the hops for 20 mins in there, as it will cool rapidly, then add that into the cooled main batch. There’s the issue that it’s hard to filter the hops out and there’s less wort exposure, but it’s a reasonable compromise for flame out style additions.

I brew BIAB and what it really comes down to is a need to employ methods other than a hot schedule because of the long cooling period.

Meatymc
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Re: 'Driving off' hop oils

Post by Meatymc » Thu Feb 14, 2019 11:52 am

Thanks again Rob. I think I'll concentrate on dry hopping as you suggest although, if you read my 'A bit of a milestone' post in the Grain Brewing section, maybe there's another way to get to where I want to be :wink:

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Kev888
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Re: 'Driving off' hop oils

Post by Kev888 » Fri Feb 15, 2019 9:48 pm

Yes, the biggest challenge isn't BIAB but rather the no-chill approach. As Rob says, that can be helped by adjusting the late hop additions, and also doing more with dry hopping at/after fermentation. IMO if you combine the two then the results can be pretty good.

Unfortunately bottles too don't easily facilitate dry-hopping shortly prior to consumption, or during dispensing; you may find an alternative way. But of course it helps greatly to brew smaller batches more frequently in order to minimise time sitting in storage, which BIAB is well suited to doing. If your recipes and brewing are honed to the point where there are no astringent (or other) faults to mellow out, then hoppy beers need not necessarily be kept for ages.
Kev

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PhilB
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Re: 'Driving off' hop oils

Post by PhilB » Sat Feb 16, 2019 3:48 pm

Hi Meaty

Here's an alternative approach to late-hopping and steeping that you may want to throw in the mix, for consideration ...
  • on brewday, proceed with your boil as usual but leave out all late hop additions in your recipe (anything in the last 15 mins, say, don't worry they'll get involved later :wink: ) ... then at the end of boil, transfer your wort to your no-chill to cool
  • just because the method is called "no-chill", of course, doesn't mean you're not allowed to chill your cube :? ... so once it's cooled to a reasonable ambient temperature you can put your cube in a fridge or cold place/pond, anything you can to get the wort in it as cool as possible
  • then when it comes to transferring your wort, take a gallon or so into a stockpot, bring it to a boil (to sterilise the pan) and perform a short boil on that portion adding your late-hop additions into it ... 15, 10 and 5 min additions, flameout, you could even add in some of your chilled wort from your cube to bring the wort in the pot down to 85 or 75C (or whatever temp you want to do any post boil steeps at) if there's room (or sit it in a sink of cold water if not)
  • meanwhile if you transfer your chilled wort from your cube to your FV, and transfer the hot portion through a sterilised strainer, then you should find that the two portions when mixed will even out to a reasonable pitching temp :?
... all of this makes the process at transfer a little more involved, but the process on brewday is a little less complicated to compensate for that :? ... and it does mean you're much closer to following whatever recipe you're looking to brew, so should be producing something much closer to what the recipe originally intended :wink:

Cheers, PhilB

Meatymc
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Re: 'Driving off' hop oils

Post by Meatymc » Mon Feb 25, 2019 1:10 pm

Apologies to Kev and Phil - hadn't noticed your posts after my last one - don't know why.

Firstly, although I put a dozen bottles away on each brew in the rather forlone hope I've some alternative stock to fall back on, I'm usually into the bulk of the brew within a couple of weeks and usually all gone by a couple of weeks later. Even the 'stock' rarely lasts more than a couple of months. I of course put this down to a rigorous Quality Control regime :wink:

As for your idea Phil, that will certainly be getting a trial this weekend. Next up is an attempt at a Baby Faced Assassin clone so lots of Citra - should be a good test of the above

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