How Fast Does Ground Coffee Go Bad?

It’s very satisfying to start the day with a great cup of coffee. It’s like fuel that fires up your body and gives you that needed boost to be at your best for the whole day.

But this perfect beginning can easily be ruined by a cup of stale coffee.

Have you had that experience before?

If not yet, lucky you. But for those who had the unfortunate moment of sipping a stale coffee, I feel you. It can be very frustrating.

What Makes Coffee Taste Stale?

There are at least three common reasons why coffee can go stale.

  1. Temperature

There is a prescribed water temperature in order to achieve the perfect cup of coffee. To best enjoy coffee, the water used should be between 195 degrees to 205 degrees Fahrenheit. Anything lower or higher than this temperature range will affect the taste of coffee. Often, when we leave our coffee in a mug, it will only take about 5 minutes and the temperature significantly drops. Temperature plays an important role in keeping good tasting coffee.

  1. Hygiene and cleaning

No matter how fresh the coffee is, if we use a dirty coffee brewer or an unclean mug, this can easily affect the taste of our coffee. For example, a coffee maker that has calcified deposits or mineral build up due to water hardness can easily alter the taste of coffee. A coffee mug that has been used so many times and has been subjected to poor cleaning practices can also contribute to the change in coffee taste.

  1. Bad ground coffee

Coffee beans can go bad. Ground coffee can go bad. And if these end up in your coffee, it’s going to be one bad coffee.

How fast does ground coffee go bad?

Ground coffee is an agricultural product. Just like any other fresh produce, it has a specific shelf life. Think about best before date or consume on or before date. Taking in consideration of this will ensure that you can have a perfect tasting cup of coffee.

According to coffee roasters, green coffee beans have a longer shelf life. Some say that it can last for up to 12 months, when stored properly.

Once green coffee beans are roasted, they lose some of their freshness. Heat plays a factor in this process. When coffee beans are roasted, they start expelling carbon dioxide. The coffee beans are exposed to oxygen.

Oxygen easily affects the composition of organic matter, like coffee beans. The more it is exposed to oxygen, the faster it will decay. When coffee beans are roasted, they are exposed to heat and oxygen. Double whammy?

Given these conditions, coffee beans often have a shelf life of 3 to 6 months. Coffee roasters often pack coffee beans in airtight, vacuum-sealed bags in order to preserve its freshness.

How about pre-ground beans?

There are several factors to consider when it comes to pre ground beans.

  1. Roasted on date. Knowing this will help you determine how long it has been since the coffee beans were roasted and ground. Unfortunately, some supermarket pre ground coffee packs do not indicate this date. In this case, buy at your own risk.
  2. Consume before date. Knowing this will help you determine how close it is to the 24-month shelf life. Technically, coffee has no expiry date. At least not in the sense of mold growing among the particles of ground coffee. It takes a consider amount of moisture for mold to grow inside an airtight, vacuum-sealed pack of coffee. However, perishable, agriculture-based products like coffee have a maximum shelf life of 24 months. If you see the consume before date that is almost a few months away from the 24-month period, choose wisely and shop for a better, fresher pack.

Pre ground coffee should be consumed immediately. If you buy a pack of pre ground coffee, consume it within a week.

Otherwise, you will notice that the taste of your coffee changes every day. The quality will diminish day after day, until your next cup of coffee tastes bitter and dull.

Do not wait for this day to come. You will be sorry you had to taste this kind of stale coffee.

Why does coffee ground go bad quickly?

Unlike coffee beans, ground coffee has more surface area. The whole beans are broken down into smaller particles and each of these particles are exposed to the four main enemies of coffee: air, moisture, heat and light.

  • Air – Oxygen is the number one enemy of coffee. It speeds up the decay of the coffee beans. One way to reduce exposure to air is keep ground coffee in airtight, vacuum-sealed container.
  • Moisture – Too much moisture can cause mold and mildew build up. This will easily make your ground coffee bad. While you can let it air dry, the molds could affect the taste of your coffee beans and the stale-like smell can retain even after you brew it. You can place your coffee beans in a vacuum-seal pack, zip lock or airtight containers to avoid exposure to sudden temperature change and humidity.
  • Temperature – Ideally, ground coffee can be kept at room temperature, which generally falls between 20 and 25ºC (68 to 77ºF).
  • Light levels – Pack coffee beans and store away from direct sunlight. Too much light can cause premature aging and it can lose aroma and flavor faster than expected.

How can you keep ground coffee fresh?

You may start to think that ground coffee are so sensitive. In a sense, yes. If you want fresh, great tasting coffee, you really need to choose your ground coffee with care.

Here are some tips on how you can make a perfect cup of coffee using fresh ground coffee.

Make your own roast.

Since unroasted, green coffee beans can last up to 12 months, keeping unroasted beans seem to be a good idea. However, keep in mind that you will need to roast beans every time you need to make a cup of coffee. There are quick ways to roast your own coffee beans. You can use a stovetop popcorn maker. Just keep a watch on the coffee beans and keep moving the beans around to ensure even roasting. Watch the color change until you achieve the roast that you love.

Buy less whole beans.

If roasting your own coffee sounds too intimidating, you can always buy whole beans and grind the beans on the demand. Coffee roasters can now be contacted online, through social media handles and coffee forum groups. This way, you can get in touch with the roasters and inquire about freshly roasted coffee beans. You can buy whole beans good for a month. Also, invest in a simple burr grinder.

Buy less ground coffee.

If you feel that grinding beans can be tedious and you want something really easy to prepare, buy ground coffee that’s good for a week. A week is the optimum shelf life for pre ground coffee. Choose the type of coffee beans you like from your favorite coffee shop and ask them to grind it. Keep in mind the kind of grind that you need, depending on your coffee brewer at home. If you have an espresso machine, make sure to choose fine ground, dark roast coffee. If you have a moka pot or an automatic drip machine, choose and semi coarse ground coffee. If you love using a French press, choose a coarse ground coffee.

Consume brewed coffee in an hour.

Brewed coffee can taste good for an hour. Beyond that, no matter how fresh your ground coffee is, you will end up with a stale cup. If you cannot drink your coffee immediately, make sure to store the coffee in an insulated, double wall travel mug. This will keep your brewed coffee fresh for up to six hours.

How Quick Does Ground Coffee Go Bad?

how long does ground coffee last
There’s no getting around it, ground coffee doesn’t last very long; in fact it is coffee at its most vulnerable.

The grinding process takes a whole coffee bean and changes it’s form to create the highest surface area possible. All of the grounds’ surface is then exposed to the elements (air, moisture, and light) and that’s why causes coffee to start going downhill.

It is best to keep your beans (in all their complete unground, whole-bean glory) for as long as possible.. and even then you should keep those whole beans stored in a proper container.

Coffee should remain in whole bean form until just before you turn grind them and turn it into a cup of the good stuff.

As a rule of thumb pre-ground coffee that you buy sealed at the store is already old by coffee standards – that’s why it’s really hard to make really awesome coffee from packaged coffee grounds.

If you grind the beans yourself and put them in something like this instead of something like this then your grind will stay fresh enough for a week to 10 days before most people start noticing the difference.

Also as a rule of thumb, so long as coffee grind doesn’t get wet it won’t ever really go bad. Even if it’s a couple of years old it’ll be fine, it will just be stale. It simply won’t taste good.

Related Reading: Pre-Ground Coffee vs Whole Bean Coffee

Ideally you would buy whole coffee beans and grind them yourself while storing them the whole beans in a nice airtight container… but if for some reason this can’t be done you need to take precautions to make sure you keep your ground coffee at its best for as long as possible.

Does Ground Coffee Go Bad or Just Lose Freshness?

do coffee grounds go badWhen you take whole coffee beans and grind them the grounds starts oxidizing quickly. Over the course of hours freshness declines and within days ground coffee will start to taste stale. Ground coffee doesn’t ever really go bad unless it gets wet but it does start tasting bad compared to fresh ground coffee.

Now, as a sort of semi-disclaimer, it’s important to tell you that by going ‘bad’ I mean passing its peak flavor. It’s not going bad in the moldy and dangerous sense of the word (except for it it gets wet) but it merely deteriorates and tastes flavorless or otherwise stale.

A bad “stale” cup of coffee won’t harm you physically. Coffee beans, even those that are ground, don’t become a health threat for years, but they develop a dull flavor much sooner than that. Most coffee lovers claim to notice a deterioration of the flavor in ground beans within a couple of weeks from grinding, about twice as fast as un-ground coffee.  But the barista behind the counter of any descent coffee shop will say in a matter of minutes, especially with the fine grind for shots of espresso.

Need a coffee storage container? See this post to check out our favorite airtight canisters.

It should be said however that brewed coffee is another animal. If you brew coffee and then let it sit unrefrigerated it will start going bad relatively quickly especially it the oils remain in the coffee. They will start growing bacteria and eventually mold just like any other perishable product in a matter of days.

How Long Does Coffee Last Anyway?

Does Ground Coffee Go BadThis depends on a number of things:

  • Whole coffee beans will stay fresh for a couple of weeks in a brown paper bag. When coffee beans are placed in an airtight canister that vents CO2 then they can stay fresh for 3-4 weeks or so.
  • Ground coffee beans have much more surface area exposed so they start losing their freshness quicker. Once you grind whole beans they will start losing their freshness in just a few days! This may be surprising but it’s true. Cupping two brews side by side where one grind was 5 days old and the other was just a few minutes old will usually enlighten even the biggest skeptic. You can lengthen the freshness time by storing your coffee grind properly but usually stored in a good container will only lengthen the d=freshness date to around 10 days or so.
  • Some people swear coffee stays fresh if stored in the fridge but this is just a fallacy. The refrigerator is a moist place which isn’t great for coffee grind. Also, it doesn’t stop the oxidation process either. It may not hurt the shelf life but it certainly doesn’t help it either.

How Do I Store Ground Coffee To Keep It Fresh?

The trick to preserving your coffee is storing it correctly. If kept anywhere where it comes into contact with air, moisture, heat or light then it is being affected, and sooner rather than later, it’ll go bad.

Try to keep your coffee in an airtight container – forget about the valved bags by this point, the degasing process should be well over before you’ve ground the beans. Some people keep them in vacuum sealed bags but an airtight canister or even an opaque jar is acceptable.

Here are some of the best air tight coffee storage solutions available today.

Friis 16-Ounce Coffee Vault, Stainless SteelFriis 16-Ounce Coffee Vault, Stainless SteelTightvac Coffeevac 1 Pound Vacuum Sealed Storage Container, Solid Black Body/CapTightvac Coffeevac 1 Pound Vacuum Sealed Storage Container, Solid Black Body/CapBeanSafe Coffee Storage Solutions in BPA-Free Polypropylene-BlackBeanSafe Coffee Storage Solutions in BPA-Free Polypropylene-BlackOXO Good Grips Coffee POP Container, 1.5-QuartOXO Good Grips Coffee POP Container, 1.5-Quart

If you’re storing a large amount of grounds, try to use a large canister to store the bulk of it and a smaller container for everyday use; that way you’re limiting the light and air exposure for the majority of your supply for longer.

There’s also the possibility of freezing your ground beans too, although it’s a controversial practice and most people try to avoid this where they can, although it’s better than throwing your beans away and can help keep them drinkable for longer.

Avoid Storing Ground Coffee Where Possible.

The best way to avoid ground coffee going stale is by keeping it whole as long as possible, many coffee drinkers find it necessary to grind beans at home to save the trouble and it really is the best way forward. Only use your electric burr grinder just before you brew your coffee!

Anything you can do to limit the amount of time between grinding the coffee and making your drink is going to help, so buying whole beans more regularly in smaller quantities is a good idea if you can do it.

The next step is to buy a home grinder and grind the appropriate amount of beans for your current brew, whichever brew method you prefer.  Or take a look into a coffee maker with a built in grinder for coffee brewing pleasure.

Overall the main thing is to try to avoid the situation where you’re trying to store large quantities of ground coffee, it’s not the best way to do things, but if you have to do so, make sure you take as much care as possible to keep that coffee well sealed in a cool, dark place. Still, you’re only going to get a week or two of good coffee but that’s better than nothing.

With that said…

Does Coffee go Bad at all Then?

Ground coffee may lose it’s freshness over the course of a week or two depending on storage conditions and grind size while whole bean coffee may stay relatively fresh for 3-4 weeks but green coffee beans stored properly can stay mostly fresh for a few years.

The point here is that in all of these scenarios coffee has merely lost it’s freshness – it never really goes bad unless it gets wet and starts growing hair!

Things do however get a bit different when you start looking to brewed coffee. Coffee sitting at room temperature can start growing bacteria in hours just like any other kind of food or drink. My own personal cut off for room temperature coffee is about 5 hours or so but even then I usually just make a new batch.

More potent coffee, stuff that I brew in an Aeropress or Chemex for instance I wouldn’t drink after it’s been out for more than an hour. The Aeropress especially and any other espresso variant. It just doesn’t seem right.

If you place brewed coffee in the fridge for later consumption it will probably last for a week to 10 days max before getting a little funky.

Some people will freeze coffee in ice cube trays and use them for cooking and for these items I’d probably not store them for more than 6 months or so but there are no hard and fast rules to any of these numbers because temperature varies so much from house to house and fridge to fridge.

Again, here at Gathering Grounds we feel like home ground coffee grind is best and that grind should be made the day of use. If you are tempted to store coffee for the long term make sure to do it under the best conditions and absolutely protect your coffee grind and beans from moisture.

Brian Mounts

Head blogger, editor, and owner of "Top Off My Coffee", a website that has been educating readers about coffee brewing techniques and equipment since 2012.

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