Why is my hops aroma fading?

[PeterC1525230181]

I have being brewing from extract in the craft kit. I have tried various recipes of the week that have dry hops additions and some variations of my own. Most recently, I tried a 20L fresh wort from a local brewer split between two 10L batches and added 50g of dry hops to each. I was really pleased with how this one tasted immediately after 2 weeks of bottle carbonation. It had the very aromatic style I was after. However, a week or two later, other bottles from the same batch are decidedly less aromatic. It is still a pleasant acceptable drop but it is no longer as it was. In retrospect, this has confirmed a growing impression I had from earlier brews, that they were only good on hops aroma when very fresh and declined over only a week or so. Is this a known phenomenon? Why is this happening? What can I do to stop it happening?

[Lab Cat]

You can't. Hop flavour and aroma declines as the beer ages. Especially the pale ale styles which make a feature of the hops. I bottled a really nice Cascade mosaic pale and it was just right at 2 weeks. Now it's definitely waned. Still good but after a month more it'll be noticeably reduced.

I did the same pale a while back but steeped the mosaic which seemed to amp it up, for me it was way too hoppy - the mosaic flavour was very ripe stone fruit. The last 8 or so bottles were much nearer my palate - hops had subsided after 5 weeks or so.

[Norris!]

As Labrat noted dry hops tend to fade but steeping, whirlpool and short boils seem to keep the flavour and aroma a little longer, from my experience.  I did a SMASH with Amarillo and the dry hop was only 50g but the whirlpool and cube additions had 75g total and the brew held its aroma, with some decline of course, throughout the keg. I was very happy with that beer and result, so maybe try a whirlpool addition on the next brew?

[Lab Cat]

36 minutes ago, Norris! said:

As Labrat noted dry hops tend to fade but steeping, whirlpool and short boils seem to keep the flavour and aroma a little longer, from my experience.  I did a SMASH with Amarillo and the dry hop was only 50g but the whirlpool and cube additions had 75g total and the brew held its aroma, with some decline of course, throughout the keg. I was very happy with that beer and result, so maybe try a whirlpool addition on the next brew?

I always bitter a small quantity of hops for pales, then dry hop with something as well. Steeping worked well to squeeze more hop flavour per g, but with Mosaic it created an intense flavour I didn't like. Others might have love it, my test monkeys did. So it's going to be a trial and error thing with steeping to find hops that work for you.

But no matter the method, they will still fade over time. Pales are always best fresh, other styles like bitters and other dark beers will usually get better with age. That reminds me, I still have 2 Wee Heavy's from July 2019 in the vault....

Edited March 18, 2020 by Lab Rat

[BlackSands]

Yes, it's a very common complaint.  You can try 'compensate' with more late/whirlpool additions but it's not really the same as a good dry hop addition.  I've recently been 'trialling' the chilled dry-hop approach, soft-crash to 14ºC add the hops and and then cold crash after a day or two.  I can't say with certainty whether it's made a discernible difference or not - I believe it has, but there's no easy way to measure it of course.  I'd only know for sure by doing a side-by-side but that's not gonna happen!   

[PeterC1525230181]

Thanks for that sad advice! I might try leaving them a shorter time for carbonation and perhaps get another week while they are at their peak. I am not sure it would be a good idea to get into the habit of drinking the whole batch in a short time! 

[ChristinaS1]

Ditto what has been said so far. Bottlers are at a disadvantage because you have to wait for the bottles to carbonate before you can start drinking the beer, and all the while the hops are fading. One of the most helpful things you can do is to put the beer in the fridge as soon as it is carbonated, slowing the process down.  Brown, glass, crown cap bottles are the best. Flip top bottles are not very good.

Some people wait until the whirlpool before beginning to add hops, but back when I was bottling I found that including an old fashioned five or ten minute addition as well was helpful in increasing the durability of the hop flavour in the bottle. I never knew why but recently I read that short boils like that are long enough to cause the conversion of linalool into cis- and trans-linalool oxide, without destroying too much geraniol (another important aroma oil). Cis- and trans-linalool are quite durable in the bottle. Much of the linalool from whirlpool addition is bio-transformed into A-terpineol during fermentation, so it disappears....Linalool from the dry hop addition stays as linalool and is also quite durable in the bottle.  All three have slightly different floral aromas.

Cheers,

Christina.

[PeterC1525230181]

34 minutes ago, ChristinaS1 said:

...Flip top bottles are not very good...

...  recently I read that short boils like that are long enough to cause the conversion of linalool into cis- and trans-linalool oxide, without destroying too much geraniol (another important aroma oil). Cis- and trans-linalool are quite durable in the bottle. ...

Thanks for your advice. The short boils sound good. I had a career in biochemistry but the closest compounds I ever had anything to do with to these was a sesquiterpenoid insect hormone. I had assumed that all a boil would do would be to drive off volatile compounds. Conversion to more stable but similar aromas makes more sense. 

Why would it matter to hop aroma crown seals vs. flip tops? I assumed that if flip tops were not sealing well, it would be obvious from loss of carbonation.

[BlackSands]

1 hour ago, ChristinaS1 said:

Some people wait until the whirlpool before beginning to add hops, but back when I was bottling I found that including an old fashioned five or ten minute addition as well was helpful in increasing the durability of the hop flavour in the bottle. I never knew why but recently I read that short boils like that are long enough to cause the conversion of linalool into cis- and trans-linalool oxide, without destroying too much geraniol (another important aroma oil). Cis- and trans-linalool are quite durable in the bottle. Much of the linalool from whirlpool addition is bio-transformed into A-terpineol during fermentation, so it disappears....Linalool from the dry hop addition stays as linalool and is also quite durable in the bottle.  All three have slightly different floral aromas.

Interestingly I noticed the same but at the time I didn't know why.  5 - 15min additions are common in all the beers I brew these days and occasionally I do a FO.   I was doing sub-80ºC additions for a while but can't say I was aware of any supposed benefit.   I suppose one could cover all bases, just in case, and add late boil additions, FO additions, sub-80ºC hopstands/whirlpool AND dry hop as well!

 

29 minutes ago, PeterC1525230181 said:

Why would it matter to hop aroma crown seals vs. flip tops? I assumed that if flip tops were not sealing well, it would be obvious from loss of carbonation.

There could be an issue with oxygen ingress around the seal.  And there's also this:  http://brulosophy.com/2020/01/20/bottle-conditioning-crown-cap-vs-swing-top-exbeeriment-results/   

 

[MitchBastard]

I’ve found if I dry hop later in the ferment I get a much more sustained and pronounced aroma. I usually whack em in maybe day 8 or 9, long after primary ferment is done and C02 could potentially Be pushing out your hop aromas.

i also saw something recently about having only 3 days contact time but I usually cold crash with them in the fermenter, giving my beers about 5 days contact time before transferring to keg. 

[PeterC1525230181]

31 minutes ago, MitchBastard said:

I’ve found if I dry hop later in the ferment I get a much more sustained and pronounced aroma. I usually whack em in maybe day 8 or 9, long after primary ferment is done and C02 could potentially Be pushing out your hop aromas.

i also saw something recently about having only 3 days contact time but I usually cold crash with them in the fermenter, giving my beers about 5 days contact time before transferring to keg. 

Like you, I have generally been dry hopping when the primary fermentation is done. I don't think CO2 is pushing out the aroma at that stage because it is there in the first bottle I try after allowing two weeks of secondary fermentation in the bottle for carbonation. I was generally doing 3 days of contact time, particularly in the last brew,  the one I was most happy with from the first few bottles in the first week after the 2 week carbonation but increasingly disappointed with in the subsequent couple of weeks.  BTW. The bottles are kept in a cool dark bathroom with no external light and artificial light for only short periods. 

Edited March 19, 2020 by PeterC1525230181

[ChristinaS1]

3 hours ago, PeterC1525230181 said:

The bottles are kept in a cool dark bathroom with no external light and artificial light for only short periods. 

A cool dark bathroom in Australia is probably still 20C, isn't it? That is good for the secondary ferment in the bottle, but too warm for the purposes of preserving hop aroma. A fridge is what you need, or a chest freezer with a Inkbird temperature controller to keep it at fridge temps. A chest freezer will allow you to keep multiple brews cold, but you probably still want to consume hoppy brews before they have been in the bottle for five weeks (the first 10-14 days of which they are carbonating).  A beer stored at 30C will age twice as fast as one stored at 20C. One stored at 20C twice as fast as one stored at 10C. One stored at 10C twice as fast as one stored at close to 0C. And whether hoppy or not, cold conditioned beer tastes better than beer stored at ambient. 

As to why flip top bottles are bad, it is because the seals absorb hop aroma compounds. If you use crown caps, the ones that absorb oxygen are best, as regular liners also absorb hop aroma. 

Regarding the length of the dry hop addition, there has been a trend from longer (~7 days) to shorter (~2 days) dry hop periods. FWIW, I recently watched a video with John Kimmich, of the Alchemist, talking about how he makes Heady Topper, supposedly one of the best IPAs in the world. He is a real believer in four days. 

Cheers,

Christina.

Edited March 19, 2020 by ChristinaS1

[PeterC1525230181]

9 minutes ago, ChristinaS1 said:

A cool dark bathroom in Australia is probably still >20C, isn't it? That is good for the secondary ferment in the bottle, but too warm for the purposes of preserving hop aroma....

Thanks. That clarifies things for me. My bathroom in Canberra, low and central in the house, is stable around 20 degrees this time of year.  I had had the impression that continuing to store at 20 degrees (and low light) with chilling only just before drinking was preferable but I now appreciate that cooler storage is better for what I am particularly trying to achieve. I am not sure where I would put any sort of actively cooled storage. I'll give that some thought! Cheers.

[ChristinaS1]

@PeterC1525230181 If you don't have room for a storage fridge another thing you can do is to get a craft fermenter or two and make smaller batches, more often.

I believe there is a lot to be said for smaller batches as they can be made in a kitchen, on a stove top, and are easy to chill in the sink. It does not require a lot of equipment (just a pot and a grain bag), or space. Makes the transition away from pre-hopped kits to un-hopped extract or all grain cheap and easy. I would give small batch brewing serious consideration.

Cheers,

Christina.

 

Edited March 19, 2020 by ChristinaS1

[PeterC1525230181]

8 minutes ago, ChristinaS1 said:

@PeterC1525230181 If you don't have room for a storage fridge another thing you can do is to get a craft fermenter or two and make smaller batches, more often....

Thanks. That is what I have! Two craft fermenters. My last batch was 20L split across both. More than I usually do in one craft kit, but that was because I tried a fresh wort kit from Tumut River Brewery, which was really nice with a generous Ekuanot dry hop addition for 3 days after the primary fermentation had died down. 

[ChristinaS1]

Perfect! With two craft fermenters the world is your oyster. 

 

 

[ChristinaS1]

7 hours ago, BlackSands said:

 I suppose one could cover all bases, just in case, and add late boil additions, FO additions, sub-80ºC hopstands/whirlpool AND dry hop as well!

Yes, I think that is the best way to go about it if you are bottling, and make smaller batches!

BlackSands, you probably have all of the equipment you need to make "half-size" all grain batches.  Forget the pre-hopped kits, you don't need them. A 30 minute boil is fine for the wort, and you can either add a small amount of Magnum at the beginning or wait until 10 minutes and add a larger amount finishing hops....Centennial is a cheap, high linalool and high geraniol choice for the 10 minute and FO additions. Save your expensive hops for the 80C addition and the dry hops. 

Cheers,

Christina.

Edited March 19, 2020 by ChristinaS1

[BlackSands]

3 minutes ago, ChristinaS1 said:

BlackSands, you probably have all of the equipment you need to make "half-size" all grain batches.  Forget the pre-hopped kits, you don't need them.

Well, someone hasn't been paying attention!    Apart from my most recent brew, and perhaps one other I've mostly been brewing 18-20 litre stove top AG batches (AG being 85% - 100% grain) for quite some months now - maybe 10 batches so far?   And with my mash efficiency being up around 85% recently, as a result of a 4:1 water:grist ratio discussed elsewhere, it's really helped keep the LME component to a minimum.   

 

7 minutes ago, ChristinaS1 said:

A 30 minute boil is fine for the wort, and you can either add a small amount of Magnum at the beginning or wait until 10 minutes and add a larger amount finishing hops....Centennial is a cheap, high linalool and high geraniol choice for the 10 minute and FO additions. Save your expensive hops for the 80C addition and the dry hops. 

I use different hops as pricing is quite different here in NZ so generally for me locally grown hops are a better option. Magnum however is not too badly priced but there still are slightly cheaper NZ options that I prefer for bittering purposes.   I'll probably take another look at local offerings that may be close to centennial but the usual NZ hop websites I know of don't actually list linalool and geranoil. 

[ChristinaS1]

44 minutes ago, BlackSands said:

Well, someone hasn't been paying attention!    Apart from my most recent brew, and perhaps one other I've mostly been brewing 18-20 litre stove top AG batches (AG being 85% - 100% grain) for quite some months now - maybe 10 batches so far?   And with my mash efficiency being up around 85% recently, as a result of a 4:1 water:grist ratio discussed elsewhere, it's really helped keep the LME component to a minimum. 

True, true! 

But 18-20L is still a relatively large batch. My point is to make smaller batches more often, so you avoid the hop fade issue. Plus you could avoid using LME altogether.

Recently a listened to an interview with a maltster with many years of experience. He strongly advocated that craft brewers discontinue the use of light base malts (~1.8L) in favour of pale ale malts (3-3.5L), as you get a lot more flavour (melanoidins) from them. Makes sense to me. Why use Pilsner or light base malts and then turn around and add Munich / Vienna / Melanoidin malts to them, to try to make them maltier? Just use a maltier base malt (ie., local or British pale malt) from the beginning and simplify the grain bill. He explained that light base malts were developed for macro breweries that were using a lot of non-diastatic adjuncts like corn or rice to brew cheap American pilsners. Ales do not require such light base malts, especially if you are adding crystal or roasted malts to them. 

Yeah, I noticed that NZ hop growers don't provide much info on the oil content of their hops. 

Cheers,

Christina.

Edited March 19, 2020 by ChristinaS1

[BlackSands]

11 hours ago, ChristinaS1 said:

But 18-20L is still a relatively large batch. My point is to make smaller batches more often, so you avoid the hop fade issue. Plus you could avoid using LME altogether.

Recently a listened to an interview with a maltster with many years of experience. He strongly advocated that craft brewers discontinue the use of light base malts (~1.8L) in favour of pale ale malts (3-3.5L), as you get a lot more flavour (melanoidins) from them. Makes sense to me. Why use Pilsner or light base malts and then turn around and add Munich / Vienna / Melanoidin malts to them, to try to make them maltier? Just use a maltier base malt (ie., local or British pale malt) from the beginning and simplify the grain bill. He explained that light base malts were developed for macro breweries that were using a lot of non-diastatic adjuncts like corn or rice to brew cheap American pilsners. Ales do not require such light base malts, especially if you are adding crystal or roasted malts to them. 

I guess the reason I have stuck with the larger batch sizes is that they are more efficient in terms of the amount of work involved - same effort but twice as much beer!  But I get your point re: hop fade.   I think I've only ever used pilsner malts 2 or 3 times.  Otherwise it's almost always Galdfield Ale, or their American Ale malt that go into my brews.