Science behind aging beer

At the bare minimum, many people can get more enjoyment over admiring a beer for 6-18months, then drinking it at an opportune time with friends, as opposed to just going home and drinking it the day they get it.

Usually BA stouts I regret not drinking sooner. The only things I've experienced aging "improving" is high IBU RIS or American Barleywines, where the hops fade and the maltiness and mouthfeel all roll into a nice creamy drink. That's a bit of a product of habit though. If they brewed Expedition without the high IBU, I'd probably jsut drink it fresh.

But no other than hops breaking down, I have no experience with anything aged getting better or any high ethanol notes going any other way, other than oxidation (which is okay in beer and wine but not an incredibly interesting attribute usually.

 

The yeast in some beers is affected by the process of fermentation with time which gives to the beer new flavor. But I have only tested this one time with la "Trois Pistoles" and it was a major improvement with a porto finale that I didn't have when I drink that beer at an earlier age.

 

I am by no means an expert beer sampler of aged vs. fresh side by sides (this only applies to beers that are cellerable), but in my limited experience with this I really only find maybe 1/2 of beers get better with some age over fresh version.

General rules of thumb:
Barrel Aged beers lose some of the "heat" of the alcohol or barrel flavors with age (bourbon, rum etc)
Hoppy bitterness fades over time aged if the beer is heavily hopped / high IBUs
High ABV beers generally get sweeter/maltier with age

If someone would like to add comments on how the tastes change from aging sours please add.

FYI...recent side by side with fresh Backwoods Bastard vs. year old...I preferred the look, smell and flavor of the fresh 2016 over year old 2015.

 

What a funny coincidence. For what it's worth, I just had a fresh Expedition and a 1 year old Expedition. I had them side by side and blind. The bitterness was actually much more pronounced in the old Expedition. The wonderfully rich malt character of the fresh Expedition had faded in the aged beer. The balance had shifted in the opposite direction from popular thinking. The aged beer was "fruitier." I realize that the first two observations are backwards from some conventional thinking. My observations were purely subjective rather than scientific, and they were naturally limited to the exact circumstances of those two particular bottles. Someone might have the exact opposite experience. I posted to highlight that rules aren't always rules. I also had two other stouts in the blind tasting, so this wasn't just a case of me picking out the fresh vs aged one.

 

Fussel alcohols present in beer transfer electrons to malt melanoidins creating aldheyde.

That is from page 7 of Patrick Dawson's fantastic book, Vintage Beer Tasters Guide

Anyone cellaring beer should think about buying a copy of this book. There are only a few mentions of the science involved, but it is a great read

https://www.amazon.com/Vintage-Beer-Tasters-Guide-Improve/dp/161212156X

I have no affiliation with the author or book. Another BA thread recommend the book a couple of years ago. I bought a copy and It was a great read. There was alot of information I already had known, but I also learned quite a few new things as well

 

More info

http://draftmag.com/required-reading-the-chemistry-of-beer-aging/

 

I would add to that, the review of the review mentioned in the article: https://beersensoryscience.wordpress.com/2010/11/15/chemistry-of-beer-aging/

 

I think the bitterness that might have been attributed to the hops there might have actually been the roast of the malt. I noticed that Bell's Jupiter (brown ale) and 30th Anniversary were really bitter fresh, but in a burnt sorta way. After a year, those flavors started to turn to a sweeter/caramel type flavor that was really enjoyable.

 

I was going to post this as well, was a great read with tons of info. Also great recommendations on beers to cellar and how to properly do it.
Some of the styles he recommends for aging are:
Imperial Stouts, Barleywines, Belgian Quads, Gueze, along with a couple others
Cheers!

 

I have seen this in a few beers. My thought has always been the hops dying out taste more grassy and kinda bitter. I hate that flavor profile, so I have to be cautious when aging certain beers; drink now or drink in 3 years... Expedition can definitely be the way you described, but again, I've always chalked it up to decayed hop flavors. No clue if that's true, just what I've perceived.