shelf life (Why do commercial products last so longer?)

[evilhorse]

What is the mechanism by which beer ages (and hence has a shelf life) in beer? Why do commercial products last so long unopened compared to most microbrews? Is it oxidation at bottling?
This is not a question about spoilage organisms/refermentation! Pasturisation kills that stuff off but he beers still eventually go bad even with the big guys?:rockin:

 

[homebrewer_99]

Pasteurization and preservative chemicals.

I read once that AB adds 50+ chemicals to their "beer"...

 

[Saccharomyces]

A lot of commercial brews are also filtered... filtering strips out yeast and bacteria leaving a clean product which if pasteurized should be stable.

I'll stick with 'living' beer, myself. Enjoying following the subtle changes in a beer as it ages is a lot of fun, especially when it's yours!

 

[knipknup]

My beers get better with age. Usually the last bottle is the best and I'm sad when it is gone. The born-on-date is as bunk as the beer it is stamped on. Many people collect bottles of annually brewed beer with no worries of it going bad. What did you hear that makes you think micro-brews go bad?

 

[dontman]

I just RE-hooked up a keg of IPA that I thought was way too bitter and just plain unbalanced back in January when I first tapped it. It has been sitting off to the side for 9 months now and wow! it is just excellent. The thing that is really surprising me is that the flavor hop additions are really prominent now. It is still bitter but now it just seems balanced.

There haven't been all that many replies to this hypothesis but I have to say that I disagree with the basic premise. In my experience most microbrews, especially bigger beers, improve with age as long as they are stored and packaged properly.

On the other side, macrobeers are insipid and tasteless from the start and this situation does not change with time, for better or worse, except for in the case of clear bottled beers which get skunkier and skunkier.

 

[MBasile]

A lot of commercial brews are also filtered... filtering strips out yeast and bacteria leaving a clean product which if pasteurized should be stable.

I'll stick with 'living' beer, myself. Enjoying following the subtle changes in a beer as it ages is a lot of fun, especially when it's yours!

You do know that Stone filters theirs, right?

 

[shek]

You do know that Stone filters theirs, right?

Do they filter all of them? I'm positive I've had some beers from Stone with sediment, the only example that comes to mind right now is a bomber of regular IPA.

 

[MBasile]

Do they filter all of them? I'm positive I've had some beers from Stone with sediment, the only example that comes to mind right now is a bomber of regular IPA.

I don't know if they filter ALL of them, but I distinctly remember on the tour the guide pointing out where they filter the beers.

 

[northernlad]

The born-on-date is as bunk as the beer it is stamped on.

The first time I heard that AB distributors pull out of date product off the shelves I laughed out loud.
Some great marketing scheme.

 

[Orangevango]

Lots of microbreweries filter their beer, filtering and bottle conditioning are not mutually exclusive.

 

[evilhorse]

I would agree that many beers will get better with age, particulary those with agressive bitterness early on, and I will apologise for saying (to paraphrase myself) that microbrewed beers go off faster than others. I will put my question in context.
The question pertains particularly to lager style beer at least those with the more delicate flavour profiles, I suspect this to be true of the bigger styles also but not so evident as the 'size' of the beer is able to mask it. Anyway what I have found is that beers in cans and bottles if bought near their 'use by date' (im in NZ im not sure if you have em in the states) have a distinct character marked by a loss of aromatic hop charachter and a caramelised fruitiness? I am told by small commercial brewers that their beers have a much shorter shelf life than the big boys?

Why?