Hop forward beers should not be drunk 5 weeks after they have been bottled or kegged.
Any IPAs and Pale Ales I brew, sit 11-12 days in the fermenter and that's with 2-3 days of dry hopping. At days 11-12 I bottle it and I have well-carbonated beer in 5-7 days. At day 10 days I am drinking that and sharing with friends and family. But I don't think I ever had similar styles sit with me more than 4-5 weeks from bottling, so hoppy beers should be drunk fresh... and quick. Hop flavour does not develop with time, it actually dulls and fades with time. Recent studies/articles written on the subject of dry hopping show that you do not need to dry hop for more than 2 days. Hop oils are extracted in the first 24 hours or so.
Shelf life can be increased by minimizing protein in the kettle by using finnings and an extended whirlpool, using maybe Brewtan B or other similar stuff and by avoiding O2 as much as possible, as 02 is your biggest enemy, when it comes to hop heavy beers.
I agree oxygen is the enemy, and I agree beers should be drank fresh(sorta).
Danger-warning-look away- If you don't like science.
Dalton and Ficks Laws AKA gas laws.
The amount of oxygen before staling accelerates is 150ppb, this is the industry standard. SO even if you have a flawless bottle session, due to the laws above, you ingress 5-7ppb per day (we will use 5 for easy math). It's all fine and dandy until your yeast in the bottle stops and falls. One that happens its going DIRECTLY in your beer. Therefor not counting refermention for carbonation your bottled beer is a ticking timebomb.. 150/5 is 30 days before the noticeable effects of oxidation start. So 8-9 months of that is 270x5= 1.350ppm of DO, which is nearly 10x the oxidation allowed in the industry standard. :wink: Bottled beer loses freshness the fastest of any packaging. I will stop you before you say you used o2 absorbing caps, because if you did and you sanitized them they are done. Due to the DO in water (~5-7ppm) those caps used all the scavenging power the second you dunked them.
What all you bottlers should do, is to add the priming sugar to water then boil it. Then inject it into the fermenter. Allow fermentation to pick back up steadily, then bottle. This protects all point of ingress in the bottling process.
Yeast are not absorbing o2 when there is no food source its a simple as that.
The reason naturally carbonated beers (this is not limited to bottles, either) via, spunden, krausen, or simple sugar have more antioxidant properties is because they produce antioxidants. Fermentation generates sulfites. Both of them, the main and the second (at packaging).
For ales you have <=10ppm
Lagers <=50ppm - the colder the fermentation and the strain will be dependent on actual numbers- this is a reason why zee Germans ferment cold (there are others though of course). Colder the better, which is why I also promote cold with no ramps. Ramps lose them.
So to break down why tests show naturally carbonated beers having the highest antioxidant power it's because they
do.
But it's
not because of continual oxygen consumption it's the
sulfite production in the carbonating vessel
and the oxygen consumption on the original transfer.
The bright beer transfer, is going to be the least protected because of what we outlined above. You have zero active consumption, and you are immediately digging into your first fermentation sulfites, with no second reserves. You probably expended most of them pushing the beer around to filter and whatnot.
When you transfer naturally carbonated beer, you are rousing the yeast and adding a very easily digestible food. That yeast grabs some oxygen after it stretches, grabs a quick meal then goes back to bed, at the bottom of the container. If he gets more food he will wake up, if not sleeping like a bear is he.
I think I wrote about fermentation generated sulfites years ago on the blog. The resource sections probably has some papers on this as well.
I will never say one has to stop bottling. I am just answering your question as to "why". Now the more stringent on the cold side the better/longer freshness will last. It can be done, my canned beer routinely measures 20ishppb on the orbisphere, at that rate hoppy beer freshness will last for nearly a year.
Hope this helps
Bryan