How Long Does Beer Last?

Homebrewers are eager for that first sip of their artisanal hard work, yet after carbonation, the beer may still be a few weeks away or longer from being ready. After waiting for several more agonizing weeks, our beer is finally ready and we can now enjoy the fruits of our labor. What’s left to worry about?

Brewers of this fine elixir often ponder, “How long will it last?” How long is beer good for has more than one definition. In this article, I describe how long it lasts, how long it is drinkable, and how long it is enjoyable.

Drinkable and enjoyable are subjective terms specific to each brewer. We’ll describe some of the changes a beer may go through. Some are good, some bad.

Though your beer might taste great right now, it may not be as great forever. How long will that great taste last? Each time we sample the beer we think about how that first sip will taste when the keg is tapped, or when we finally hear the pssssst sound as the CO2 gas escapes that first bottle.

Beer expiration date depends on many factors, because it’s made from many complex biological processes. Many of these changes occur during the life of the beer, and while some are good, others are bad.

During the fermentation process, a lot of chemical reactions and biotransformations occur that constantly change the beer’s flavor. However, although you would rarely actually discover this for yourself since at this stage, there is rarely any taste testing. If you were to taste at this stage, you would be tasting things that are not very appetizing.Bubbling yeast

Yeast creates and breaks down many different compounds during fermentation and some of these compounds can taste very unpleasant. We do what we can to prevent the undesirable flavors from sticking around, of course. The longer a beer “stays around,” the more opportunity for changes in the beer.

The long-lasting and great flavors in beer are at the mercy of these unstoppable chemical reactions that can give and take away great flavors. Oxygen is generally the least undesirable element that can linger in the beer. This can happen after fermentation and packaging (kegging or bottling).

Oxygen is the main cause of staling in beer and can very much dictate if the beer is going to be enjoyable or not. Other compounds including aldehydes, esters, yeast (an organism), and phenols are in the beer.

All of these continue to change the flavor throughout the beer’s lifetime. Aldehydes can also contribute to stale beer flavors that can manifest as wet cardboard or paper, or what one would imagine a musty basement to taste like.

Oxygen and aldehydes, in small amounts, may also contribute complementary flavors. Some beers fare better than others and much depends on the beer itself.

Some fruity notes may be observed, too. Esters contribute to changes over time, often adding fruit and floral flavors as well.

Phenols and phenolic flavors change over time as well. As phenols oxidize, they tend to promote stale, flat flavors in the beer.

As molecules are freed from phenols, that great banana flavor for your beer that you finally nailed, may transform into something akin to grass. Even worse, an ammonia-like aroma, sometimes described as cat pee, may develop as phenols continue to evolve.

Yeast, in abundance, may give the beer a meaty flavor. This develops over time and may be more pronounced as the beer ages.

A beer may contain unpleasant characteristics when young, but these characteristics will fade and disappear as your beer matures. Young in beer terms may mean a few weeks in a Czech Lager or a year in an Imperial Stout. Thus, young is relative to the beer’s flavor development.

For example, a young lager might smell like sulfur, while the beer is being lagered, or aged cold. An Imperial Stout may have an overly coffee flavor that mellows towards a nutty, delicious coffee flavor many months down the line.

Beers transform in both good and bad ways, and the starting point for how it lasts maybe weeks, months, or years away.

As beer flavors develop, so do the types of flavors. You might detect a savory or umami flavor, much like soy sauce. Your beer may develop an almond flavor too, reminiscent of a mild Sherry. Longer aging may produce port wine flavors.

As flavor compounds oxidize, new or more pronounced flavors can develop. You may perceive a candy, fall leaves, licorice, or leathery flavor reminiscent of worn leather. These sound unpleasant, but will add depth and layers of flavor to the beer, in a good way.

The style of beer is a critical component in the beer aging equation. While all beer styles can be aged, not all of them age gracefully.

Below are a few of these categories, and you’ll find notes on a few of the changes that might be seen in the corresponding beer style.

Changes start while the beer is still young and will progress as the beer ages for months or years to come. Beers should be stored cold to stay drinkable and enjoyable.

Here are some positive and negative changes that can occur but only time will tell how your beer will change. There are a myriad of beer styles out there, but only a few categories.


IPAs will lose hop flavor and aromas and likely have more maltiness. They tend to be best in the first couple days, then the flavor slowly degrades over a couple of months. They may still be consumed for many months but are no longer the same beer.

Malt character becomes more prominent over time. The alcohol character may also become more prominent as the other flavors change. It may just seem more “warming” on the palate or “hot” seeming boozy or strong alcohol.

Dark Beers

Dark beers often have toasted bread and grain flavors and often a prominent and malty character. These toasty and malt-forward beers tend to develop a richer, heavier, and cream/buttery-like character over time. This blends flavors and softens the alcohol, making a pleasantly rounded beer.

Dark beers will “mellow” as their distinctive flavors such as coffee, toffee, or chocolate soften and blend with other flavors remaining in the beer forming a more complex combination of flavors. This is a slow process taking months to years for the benefits to become apparent.

Hazy IPAs and Wheat Beers

Hazy IPA and wheat beers will become clear-colored over time. A clear wheat beer might be called a crystal wheat. If aged cold, all beers will become clearer. A hazy IPA that is aged until it is clear is still an IPA.

Hazy beers should be consumed immediately. That is, with a few weeks of packaging. The haze will fade and disappear, and the taste associated with hazy IPAs doesn’t get better with age. The taste fades and harsher bitterness and sharper flavors emerge.

Light Lagers and Ales

Light lagers and light ales, or clear light beers, usually get a “thinner” or watery body, and more delicate flavors that diminish. Light Lagers often taste stale noticeably sooner than other, more “complex” beers such as stouts, dunkles and IPAs.

Light lagers do not maintain flavor stability over time. This style of beer is meant to be consumed cold within a few weeks of being ready. These can stale within a couple of months and even faster if not stored very cold.

Sour Beers

Sour beers are typically ready to drink when they are deemed ready. That is, once a commercial brewer packages a sour beer for sale or the homebrewer has decided theirs is ready to drink, you should not expect it to become better with age.

Sour beers sometimes get more sour, especially homebrews, which are not typically filtered or processed to remove yeast and bacteria that make sour beers sour. Other flavors develop over time, depending on which yeast strains and bacteria are present.

You might find them more sour, more barnyard, more wet hay and other over-emphasized farmhouse characters. Sour flavors may drop off quickly, leaving the beer lacking its peak complexity.

Malty and Malt Forward Beers

Malty and malt forward beers tend to age similarly to their dark beer cousins. They may gain some of the same flavors that darker beers develop over time as the malt becomes more prominent in both.

These beers can be aged and remain drinkable anywhere from months to years. Regular sampling helps narrow down when you need to make any adjustments for your specific preference.

Bitterness will change. In big (higher alcohol) and bitter beers such as Barley Wine, you often find that the bitter flavor will mellow over time and will become less harsh.

The same is true for their lower alcohol cousins such as old ales or bitter stouts. The bitterness usually fades to a softer more pleasant character. In both styles, the malt tends to mellow and balance the other flavors.

Old and strong malty forward ales tend to age well too. Often, they need many months or even years to peak. Expect the hoppiness to drop off quickly and for the richer flavors to develop over time.

When Good Beer Turns Bad

Infected beer
A beer that’s infected.

Some beers can become infected with bacteria or wild yeast and “go bad,” or become unpleasant, over time. How much time will be hard to predict.

Bacterial colony growth can be slow and wild yeast may replicate quickly. How much sugar remains in beer will determine their growth.

Beers infected with bacteria or wild yeast don’t last long. However, if consumed quickly, a person might not even notice.

Unfortunately, the effects are usually noticeable in the form of an unpleasant smell, much like vomit, bad cheese, or smelly gym clothes. An unexpected sour or vinegar flavor indicates a bacterial infection such as Lactobacillus or Acetobacter. These are non-toxic bacteria that, when unplanned, spoil beer, rendering it hard to palate.

Unplanned, these infections rarely go well. A “volcanic” foaming bottle is a good indicator that beer is infected.

If you haven’t seen one, a volcanic foaming bottle is when you remove the cap and a fountain of beer erupts from the bottle, usually sending nearby people scattering. It can be comical, but it isn’t fun to clean up, and drinking the beer may even be worse.

You may experience gastronomical distress like bad gas or diarrhea if you drink an infected beer. You are better off dumping the it and fixing your sanitation problem.

Now, while it is possible that an infected beer transforms into a drinkable sour beer, this is uncommon. But if you have the patience and space, you can always wait and see if it transforms into something likable. I prefer to cut my losses, dump the beer, and focus on preventing infections.

Wild yeast may also create excessive foaming beers. But more often, wild yeast will add phenolic, unpleasant, or unexpected flavors. Wild yeast produces a variety of compounds that may taste like burnt rubber, smokey, metallic, sour, like wet hay, and how a goat smells.

Some beer styles infect the beer intentionally. When the infection is unintentional, it rarely makes a good beer, of course. As with bacterial infections, it is best to dump and fix the problem rather than hope it gets better.

How Long Does Beer Last?

For a beer to last months or even years, brewing practice should focus on quality process and sanitation practice. Final packaged beers should have very low to no excess oxygen, and be stored cold.

How long a beer tastes good depends a lot on the style and quality of the beer. How well beer is stored and how well sanitation practice is followed will both have a huge impact on how long a beer is drinkable and enjoyable. I have had a beer that I’ve kept around for three years that was still enjoyable to drink.

The process of creating beer has been around for thousands of years. For hundreds of years, advances in the process and awareness of spoiling agents have produced beers that last a very long time.

Recently, explorers discovered bottled beers that were crafted more than 150 years ago. The ancient beer was recovered from deep, cold, and low oxygen water. When they opened one of the bottles, the beer was said to be a “bit old but drinkable.”

Practice excellent sanitation methods, store your beer cold, be patient, and don’t fret if your beer needs a few weeks, months, or even years to finish!

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