What's with Hops and Aging?

This is a topic that causes a lot of confusion, and understandably so.

The question usually comes from people who are just getting into craft beer, enough that they have tried various styles, and have done some reading about the history of beer, brewing, and various ingredients.

"If hops are a preservative, why do people say it's best to drink IPAs and other hoppy beers fresh?"

Well, here's where it's important to separate the way hops got into beer from the reason that we use them today.

Hops were originally used as a preservative in beer.  This was before pasteurization and refrigeration, and especially refrigerated transportation and storage, were a thing.  Hops kept harmful bacteria out of our ancestors' beer, which is the origin of their use in beer.

The safety of beer, however, no longer depends on hops.  We now have pasteurization, effective packaging, and refrigeration from the brewery right through the consumer. So while it is true that beer was originally hopped for preservation, this is no longer the case.  Yes, it's even true that some popular styles of beer we drink today have their origins (in a loose, rough, kind of way) in beers that were intended to have an incredibly long shelf life while traveling through various climates.

That being said, many beers, and in particular those styles originally intended for long life and travel (IPAs), are now hopped more for flavor and aroma than anything else.  In fact, there are hops bred and engineered to emphasize particular flavors.  Individual flavors from hops, like any other flower, don't hold up particularly well with age.  They don't go bad, per se, they just don't fade.

So the reality of it is, if you were to open two beers, the same in every way, but one hoppier than another, and leave them out for a week, the hoppier beer might be "better," "safer" or "fresher" than the unhopped beer in a scientific way.  It is less likely to be affected by harmful bacteria, or to make you sick.  On the other hand, while it hasn't necessarily gone bad, it is unlikely to have the same citrus, pine, resin (think marijuana), or grassy notes that it had when it was fresh.

The same principal goes for aging beers still in their containers.  Hoppy beers don't go "bad," and in fact, are probably less likely to do so than some of the beers we age (in barrels or in bottles) more frequently, but they also aren't as great.  In fact, since many of the beers we age are more malt (sugar) focused, brewers generally have to make sure they have a significant alcohol content, and are also constantly testing barrel aged beers for the presence of harmful bacteria.  You probably wouldn't have to be as vigilant if barrel aging an imperial IPA.  On the other hand, the very fresh, floral, piney, grassy, skunky, or other flavors that make people go nuts for IPAs would be lost

So, the answer is that hops are, in fact, a preservative.  They are, however, used in "hoppy" beers more for flavor and aroma, which fades over time.  You would be perfectly safe drinking an IPA that has been in your fridge for a few months.  It's just not going to have the clean, bright flavors it would have if drank while fresh.

Should I age xx, or drink it right away?

People often wonder they can or even should age a particular bottle, whether it is beer, wine, or spirits.  The answer is, it all depends on the particular item.

Spirits.  In general, spirits are high enough in alcohol content that the effects of aging them in a bottle will be minimal.  They are  not as volatile, or subject to as much chemical change as lower proof beer and wine.  Most have been aged in wood, or filtered, to the point that most cogeners have fully developed.  It's still not a great idea to keep them around too long, especially once they're opened, but they are less subject to change over time than beer and wine.

Beer.  As a general rule, beer is best drank fresh.  Beer is low proof, and has not been distilled, or (generally) aged.  The higher residual sugar and water, along with other chemicals which are still left in beer, make it fairly volatile.  Light and oxygen are both bad for beer.  Saying heat is bad for beer is a bit of an oversimplification.  Temperature changes are bad for beer.  So if you do plan on hanging on to beer (whether just for a couple of weeks or during long term cellaring/aging) keep this in mind.  A beer cellar or closet is probably the best place for it, as it will be protected from light and stay relatively temperature stable.  The most common way I've seen people mistreat beer is to buy it cold, let it sit out for a few days, put it in the fridge, then move or take it somewhere else, or just run out of space in the fridge, leave it out at room temperature for a few days, and then put it back in the fridge.  This is asking for trouble.

Now, notice that I said that as a general rule beer is best when fresh.  Some beers are meant to stand up to aging.  How do you know if yours is one of them?  Five things: hops, alcohol, body, aging, and a couple of yeast situations.

Hops will be the most counterintuitive of these.  Hoppy, bitter beers do not age well and are best consumed as quickly as possible, especially fresh hopped or dry hopped beers.  Weren't hops originally put in beer as a preservative, though, you ask?  Yes, they were.  In fact, hoppy beers are certainly safe to drink after some time.  But 1) modern brewing and packaging ensures that even beers with low hop profiles are pretty shelf stable, and 2) what we now call "hoppy" beers use hops for flavor and aroma.  As an agricultural product, and, basically an aromatic flower, hops change as they get old.  They no longer have the fresh, bright, crisp flavor and aroma they started with, meaning that while they're perfectly safe to consume, they lose the characteristics that they gave the beer and begin to taste and smell stale.

Alcohol Higher alcohol beers tend (although hops trump this, so don't try to age an Imperial IPA!) to age better than lower alcohol beers, for a couple of reasons.  Aging will tend to mellow and round out the boozy flavors that some barley wines/quads/etc. will have.  Also, as mentioned in the notes on spirits, higher alcohol means less volatile (at least in terms of flavor and aroma changes).  These beers will develop and change with  time, especially since most high alcohol beers also have a fair amount of residual sugar and fruity esters left in them, unlike spirits, but will not entirely change their nature.  They area also high enough in alcohol that most yeast and bacteria will not attempt to continue fermenting the beer.

Body Bigger bodied beers tend to age better.  Whether from alcohol, sugar, or dark roasted malts, big beers mean big flavors.  You don't want to lose that (and won't), but sometimes a mellowing, rounding out that comes with aging does a big beer good.

Aging If a beer has been aged by the brewery in wood, it usually means two things: 1) the recipe was designed with aging in mind, so there won't be any harmful effects to letting it sit a little longer in the bottle, 2) The aging process has already started, and so the effects of aging will not take a turn for the worst.  Any negative chemical or bacterial reactions would have taken place in the barrel, and you wouldn't have the beer at all.  So, it's a safe bet that most barrel aged beers will be good after a little extra time in the bottle or keg as well.

Yeast In general, spontaneously fermented and bottle/barrel conditioned beers are good to age.  Spontaneous fermentation allows a) oxidation, and b) wild and unpredictable yeast activity.  These are two things you worry about with aging a beer, and if it has already held up to deliberate exposure to these two things, chances are, they can't do a lot more harm.  The stuff that wild yeast and bacteria eat is probably already gone.  As for bottle/barrel conditioned beers, they are deliberately bottled or kegged with active yeast so that the beer continues developing.  Allowing the yeast to remain active will allow the beer to continue to develop over time (until the yeast has completely died off) and provide for a more interesting brew.

Lucky for us, several of these conditions tend to overlap.  IPAs and pales tend to be light, crisp, young, hoppy, and very deliberately fermented using cultured yeasts.  Barley wines, imperial stouts, quads, sours, etc. tend to meet more than one of the conditions I've listed for "good for aging" beers, and are usually good candidates

Wine
Rules for wine are actually not that far off from beer, but a little more simplified.  First of all, remember to keep them temperature stable and out of the way of light.  Second, I don't think there's anything in wine that has quite the same negative reaction to time that hops do, so you won't necesarily totally ruin a wine by aging it.

In general, you'll want to drink light bodied wines, especially crisp, bright, citrusy ones, pretty young.  They will tend to mellow, smooth, and become more one note over time.

On the other hand, big wines with richer, dark fruit flavors, especially ones high in tannin, will usually benefit from aging.  As with beer, anything (white or red) which saw the inside of an oak barrel is probably a good candidate for further aging as well.

Collecting/future value
Now, the one thing to note with all three of these things, especially with whiskey and wine, and it's starting to be true of some beers as well, is that aside from quality, there is a certain value to a bottle held onto for a while.  Simple supply and demand.  A 25 year old scotch or bourbon is going to be hard to find, and, to the right person, worth a lot of money.  An interesting note about wine production is that low yields often produce the best wine.  A bottle of a particularly scarce, but high quality vintage can be worth a lot of money.  Some craft and monastic beers are so hard to find that they are worth a lot of money, especially months or years after their production.  The above tips were written based on drinkability and quality, not on monetary value.  So if you are a collector primarily looking to make money, or  simply have the pride in having a valuable cellar, you can probably pay less attention to them.  That said, 1) collecting booze for the sake of future value is risky.  You are banking on the fact that a particular brand or vintage will hold value in the future.  Tastes change.  While a rare spirit, wine, or beer is probably a safe bet, keep in mind that producers change production levels, or sometimes tastes just change.  2) If it tastes like shit, it's really not worth anything to anyone.  Pliny the Younger is a very rare, triple IPA from Russian River, released once a year.  This gives it an inherent value, and might tempt some profiteers (if it was available in bottle) to tuck away a bottle and try to sell it in the off season.  They'd be out of luck, as this beer is meant to be drank young and would only deteriorate with time.  In fact, the brewery allocates kegs only to those bars who commit to tapping it in the month of February, to avoid people jeopardizing the quality of the product to take advantage of its scarcity.

Hopefully this has been a helpful guide to when products might benefit (or not) from cellaring or aging them in bottle.