Hop Flavour Dissipation

[GuyG]

Hi all,

So I brewed an XPA a few weeks ago which had finished bottle conditioning on 1st August (10 days conditioning)

I stored them in the spare room en suite (dark and room temp). They are capped brown glass bottles and I stick them in the fridge to chill as and when I fancy a couple in the evening.

When fresh it was really juicy but in the last few days a couple bottles seem to have lost their juicyness whilst the last I had seemed to have retained it.

I was wondering whether this maybe because it isn't as fresh or maybe some of the bottles had oxidised a bit although there is no change in colour or aroma on the ones that lost some of their flavour.

Or is it just a case that due to the style this is commonplace, whether I should have stored it cooler after carbonation was complete or I simply should have drank it quicker.

I have attached the hop schedule.

Any thoughts/advice would be greatly appreciated.

Thanks
Guy

 

[Agentgonzo]

Hope character fades with oxidation as you suspect. The hop aroma/flavour fades faster than the colour changes. This is more noticeable the more hops you add. High hop brews (like your recipe) will be more noticeable.

When fresh it was really juicy but in the last few days a couple bottles seem to have lost their juicyness whilst the last I had seemed to have retained it.

It is possible/probably that you filled the bottles slightly differently. The bottles that are filled higher will have had less oxygen in the headspace and I would put money on these being the ones with more juicyness. There is a good thread on here about reducing the headspace to ~5mm to vastly reduce oxidation. I now do this with all my hoppy ales. You can also add metabisulphate/ascorbic acid to prevent oxidation as well (more threads on here about it - I add ascorbic acid).

bottling wands will reduce splashing/oxygen uptake as you bottle it, but when you remove the wand, it'll be replaced by fresh air.

Removing oxygen from the headspace is by far the biggest winner, whether by filling almost up to the cap, or capping on foam.

Storing it cooler/drinking faster will give you fresher beer, but if you're careful with how you package it's not a necessity to put 40 bottles in a fridge and drink them in a fortnight.

 

[GuyG]

Hope character fades with oxidation as you suspect. The hop aroma/flavour fades faster than the colour changes. This is more noticeable the more hops you add. High hop brews (like your recipe) will be more noticeable.


It is possible/probably that you filled the bottles slightly differently. The bottles that are filled higher will have had less oxygen in the headspace and I would put money on these being the ones with more juicyness. There is a good thread on here about reducing the headspace to ~5mm to vastly reduce oxidation. I now do this with all my hoppy ales. You can also add metabisulphate/ascorbic acid to prevent oxidation as well (more threads on here about it - I add ascorbic acid).

bottling wands will reduce splashing/oxygen uptake as you bottle it, but when you remove the wand, it'll be replaced by fresh air.

Removing oxygen from the headspace is by far the biggest winner, whether by filling almost up to the cap, or capping on foam.

Storing it cooler/drinking faster will give you fresher beer, but if you're careful with how you package it's not a necessity to put 40 bottles in a fridge and drink them in a fortnight.

Thanks for the in depth advice @Agentgonzo I will certainly look up those threads

I do use a bottling wand, maybe I was a it cautious about overfilling and spilling... I also have some PET bottles which I tend to only use for the first few bottles to check carbonation levels... I guess I could also use those as I always squeeze all the headspace out before screwing the lid on them.

Still a newbie to brewing and it is always a good learning curve to endure these bumps in the road... I will smash through the rest of this batch with my friends this weekend before it turns to bitter soda water and rebrew again with the new found knowledge.

Thanks again for the advice

 

[Agentgonzo]

PET bottles are perfect for this. Always squeeze . Like you. I always put a few in PET to keep an eye on carbonation

 

[GuyG]

Will also likely look for a new beer fridge for the garage to store at cellaring temperature as I have just discovered it's currently about 24c in the en suite which certainly wont help

 

[Jim Brewster]

The hop punch often fades off after the first few weeks, sometimes it's not a bad thing as big hoppy beers can have a harsh hop burn at first

 

[hoppyscotty]

Bottle conditioning is hard for hop forward beers. Air exposure is the great enemy of hops. Contrary to some people’s understanding the air trapped inside the bottle when bottling isn’t ‘consumed’ by the yeast as the secondary fermentation that occurs during the conditioning process is anaerobic so any air trapped inside the bottle stays on the bottle and will impact the beer over time. You could add some sodium metabisulphate when batch priming, about 0.3g per 20 litres.

 

[Agentgonzo]

Contrary to some people’s understanding the air trapped inside the bottle when bottling isn’t ‘consumed’ by the yeast as the secondary fermentation that occurs during the conditioning process is anaerobic so any air trapped inside the bottle stays on the bottle and will impact the beer over time. You could add some sodium metabisulphate when batch priming, about 0.3g per 20 litres.

Not strictly true. The yeast will consume some of the oxygen (in a different metabolic pathway in addition to fermentation if I understand it correctly), but not all of it and not before oxidation reactions have occurred. It'll help reduce, but not eliminate oxidation.

 

[GuyG]

Thanks for the additional replies guys.

I've got 5 left.... most of the others we drank were fortunately still quite juicy

I use the oxygen absorbing bottle caps but not sure how much they actually do absorb.

I bottled my red IPA today which is very hop forward... I had 24 PET bottles so squeezed all the head space out so hopefully they will last a bit longer, I'll just drink the glass bottles first and hope for the best

 

[hoppyscotty]

Thanks for the additional replies guys.

I've got 5 left.... most of the others we drank were fortunately still quite juicy

I use the oxygen absorbing bottle caps but not sure how much they actually do absorb.

I bottled my red IPA today which is very hop forward... I had 24 PET bottles so squeezed all the head space out so hopefully they will last a bit longer, I'll just drink the glass bottles first and hope for the best

That’s a good strategy with PeT bottles. I like them. A lot of people slate them because they do allow air to diffuse through the PET so can oxidise and let co2 out so can lose carbonation, but this clearly takes a hell of a long time as I’ve had pet bottled NEIPA’s bottled from a Boel iTap, so about as oxygen free packaging method as possible, that have lasted months and still come out fresh.

A lot of these ‘accepted rules’ are indeed scientifically true, but what’s missing is the context around how long a lot of these process take. If you want to bottle a beer for a year or more then PET might not be the best option.

 

[SMP Brewery]

If you want to bottle a beer for a year or more then PET might not be the best option.

Thanks for the heads up. I bottled a mixture of PET and glass for the Imperial Brew & Swap, I‘lI use the PET first as testers then and leave the glass for long term.

 

[GuyG]

That’s a good strategy with PeT bottles. I like them. A lot of people slate them because they do allow air to diffuse through the PET so can oxidise and let co2 out so can lose carbonation, but this clearly takes a hell of a long time as I’ve had pet bottled NEIPA’s bottled from a Boel iTap, so about as oxygen free packaging method as possible, that have lasted months and still come out fresh.

A lot of these ‘accepted rules’ are indeed scientifically true, but what’s missing is the context around how long a lot of these process take. If you want to bottle a beer for a year or more then PET might not be the best option.

Thanks for the reply Scotty great advice there.

I tend to do a few in PET for carb checks and the rest in glass bottles (a couple clear bottles for ease of seeing how much it's dropped bright) and drink the PETs first.

I think with my original question about my XPA i genuinely may have just had a few dud caps where oxidisation had started as the others (bar 2) have still really been on song... Had another this evening and it was juicy AF.

Thought I would play it safe with the red IPA as there are about 200g total combined of chinook, citra, el dorado and amarillo in my 5 gal batch so put 24 in PET and the last dozen in bottles... I had a half out the fermenter while bottling and I was really happy with the flavour and want to retain as much of that resinous fruit salad as possible