Does Coffee Go Bad? A Primer On Coffee Freshness And Storage.

Does Coffee Go Bad? A Primer On Coffee Freshness And Storage. - Iron Bean Coffee Company

Stale coffee is a pandemic that affects coffee lovers everywhere. And the worst part is, most people have no idea they’re drinking old, stale coffee! Part of this is due to simple misunderstandings, but an even bigger reason is that big coffee companies have misled us.


In this blog post, I’ll show you:

  • How long coffee beans are actually fresh for (hint: it’s not very long)
  • Why fresh is the only coffee you should buy
  • How you can tell if beans are fresh before you buy them
  • The secrets of marketing manipulation big coffee companies use on us
  • How to extend the freshness of your beans

By the end of this blog, you’ll know the keys to brewing better, fresher coffee.

Do Coffee Beans Go Bad?

Coffee beans, like all agricultural products, are best when fresh – and they’re not so tasty when they start to go bad. Except coffee beans don’t go bad how we traditionally think by growing mold (at least, normally) because there’s so little moisture left in the beans.

They go stale.

As soon as coffee beans are roasted they start expelling carbon dioxide and slowly decaying. The chemicals start transforming, the cell structure of the bean starts to fall apart, and the best flavors of the beans start to become bitter and dull.

In fact, roasted coffee is only at peak freshness for 2-3 weeks!

And pre-ground coffee? It only has 20-30 minutes!

All of this is thanks to our friend, oxygen. Oxygen breaks everything down, especially organic things like coffee. And the more exposed something is to oxygen, the faster it’ll decay. That’s why pre-ground coffee loses its freshness so fast – there’s so much surface area for oxygen to do its dirty work.

After that first 2-3 weeks, the delicate, complex flavors of the coffee start to decline rapidly. You can taste the disappointment day after day until the only flavors left are bitter and gross.

So if you find coffee on the shelf from years ago, you can drink it, but it’s not going to be tasty at all. It’s safe, but it certainly won’t be tasty.

But Can Coffee Expire?

Coffee beans are considered a dry good, which means they have an extremely low moisture level. This keeps mold and other things from growing on them, which is why some people find old cans of coffee grounds at their grandparents’ houses that seem normal, despite being a decade old.

However, not all coffee beans are expire-proof. If the grounds are extra-oily, those surface oils can enable mold growth. Similarly, if the beans are stored in a damp environment and soak in moisture, they could become a breeding ground for mold and bacteria.

But you probably have nothing to worry about. For normal people living in normal homes, it takes a year or ten for beans to soak up enough moisture to start growing mold and truly expire.


How Coffee Marketers Have Deceived Us For Profit

You probably used to think coffee was fresh for weeks or months. I mean, coffee bags have a “best by” date that’s months in the future, right?

It’s all clever marketing.

Some coffee companies try to pull the wool over our heads by stating coffee is fresh for months as if it’s fact. Except it’s not – we know that now. Those “best buy” dates far in the future are deceiving, and it’s all so coffee companies can keep stale beans on the shelves of grocery stores for months without us realizing that’s a bad thing.

Supermarket coffee is almost always stale coffee.

So here’s what you need to look for instead: a “roasted on” date.

Roasters that are focused on quality are transparent about when they roast their coffee. We don't roast a bean until you order it. Your Roast on Date is 99% the day you order it. The other 1% is the day after we roasted it. 

Why You Should Only Buy Fresh Coffee

Fresh coffee is full of live, full of flavor.

The acids are crisp and clean. The sugars are sweet and satisfying. The aromas are rich and captivating. And there’s virtually no bitterness – and any bitterness that is in the bean actually helps balance out the bright acids. Note ( Highly Caffeinated Coffeess are often more bitter due to the Robusta Beans used. Caffeine is just bitter)

Fresh coffee is amazingly balanced.

Life’s too short to waste on stale, bitter beans. Buy the good stuff, throw a flavor party for your taste buds every morning, and start your day on the right foot.

Here’s what we suggest: buy coffee beans roasted within the last 7 days. If you try to find coffee roasted 1-2 days ago, you’ll probably be searching forever. But 7 days is a good standard – fresh enough to give you another full week of peak freshness, but loose enough that you can easily find beans this fresh online.

Extending Freshness: The Best Coffee Storage Containers

We already talked about oxygen, but there are a couple of other things that can actually make coffee go stale faster:

  • Light – Both sunlight and artificial light initiate a process called photodegradation that makes organic things fall apart. This is why you want to store your coffee in an opaque container that doesn’t let any light through. So no mason jars – get a proper storage container.
  • Heat – Molecules literally move faster when hot than when cold, which also means organic things decay more quickly when hot (hence, we store food in the freezer to preserve it). Don’t store your beans in a warm place.

Using a dedicated coffee storage container can actually extend the freshness of your beans by keeping them away from these harmful elements. Rather than just 2-3 weeks of peak freshness in the coffee bag, you can have 3-5 weeks of stellar flavor!

WE Just happen to have the Perfect Container right here

Does Brewed Coffee Go Bad?

We’ve talked a lot about bean freshness, but what about coffee you’ve already brewed? Does our black gold go bad if we forget to drink it?

It sure does.

The culprit, again, is oxygen. Oxidation (decay via oxygen) also affects your coffee once it’s brewed. While the organic compounds in your liquid coffee break down, the most noticeable change happens when the pH (acidity) of your coffee is raised.


Ever wondered why old coffee tastes gross, bitter, and strangely lemon-y? This is why.

does brewed coffee go bad

This is why you shouldn’t let a pot of coffee sit around for hours and hours (unless you can vacuum seal it off). It’s going to become less and less tasty as time goes on. Once again, fresh coffee is the best coffee!

So How Long Can Coffee Sit Out Once It’s Brewed?

You’ll probably start to notice your coffee’s flavor decay and become less pleasant after an hour or two of making it. After four hours, those acids will start tasting really tart and there will be an intense bitterness.

Beyond this, it’s impossible to say exactly how long coffee can sit out for, but we do know that mold spores can attach and grow to food after it’s been at room temperature for 3-5 hours, so I wouldn’t suggest drinking coffee that’s been sitting out for more than 5-6 hours, and I definitely wouldn’t drink it the next day. Even if it looks fine, it may not be.

Better safe than sorry – just make a fresh (and far more tasty) mug if it’s been more than a few hours.

Does Coffee Go Bad – A Summary

Let’s look at everything we’ve explored today that has to do with coffee freshness.

  • Whole beans have 2-3 weeks of peak freshness and flavor
  • Ground coffee only has 20-30 minutes of peak freshness
  • Always buy coffee with an honest “roasted on” date
  • Avoid coffee with a “best buy” date far off in the future
  • You can extend your coffee’s freshness by 1-2 weeks by using a vacuum coffee canister
  • Brewed coffee starts to decay after 1-2 hours but is safe to drink for many more

Well, that’s about all there is to be said about coffee going bad (aka, stale). If you have any other questions, feel free to leave a comment or reach out. I’ll gladly answer!

1 comment

  • Erik Glauvitz

    What about freezing beans?

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