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How to Tell if Coffee is Rancid

Coffee lovers everywhere know there is magic brewed into every cup. The pleasant aroma, the ritual, and the feeling of knowing the caffeine will hit soon all come to mind when I think about brewing up a cup of joe.

What about those times when your coffee doesn’t taste quite right, or the smell is not coming through as strongly? How do you know you are drinking the freshest, best-quality coffee? Will drinking old coffee make you sick?

The short version of the story is as coffee beans decompose, they will have unwanted chemical reactions that will cause the flavors to go bland and eventually rancid.

Coffee is safe from bacteria for the most part, but if the coffee gets wet or is stored in a moist place, it can grow mold and mildew.

That will degrade the coffee and the beans will begin to sour. At some point, this coffee becomes unsafe to drink because it can make you sick.

All coffee types will go bad if not stored properly. Factors that influence shelf life include the amount of oxygen it is exposed to, the form it is stored in, and the containers it lives in.

How to tell if coffee is bad?

Coffee looks about the same no matter its age. There are several ways to determine if coffee has gone bad.

The best way to tell if a cup of black coffee is bad is to conduct a sniff test. When coffee has gone bad, its smell will start to fade. The taste will not be as strong either. Drinking coffee at this level is not dangerous, but it will not be the best tasting coffee you have had either.

*Consuming expired foods can be dangerous. Please use your best judgment.*


New coffee beans will give off a strong aroma with notes like caramel or chocolate. Stale coffee may start to smell more like an ashtray. It has also been described as smelling dusty or mildewy. This is true for coffee in all its forms: ground, whole, or instant.

The reason coffee beans slowly lose their flavor, especially after grinding, is because the oils begin to evaporate. The oils are what hold all the good flavors.

Just like with any food product, the amount of time a person is willing to use a product after its best-by date is up to them. Coffee drinkers who want a fresh cup of coffee will be less likely to keep beans past their expiration date. The lower the taste standards, the longer the coffee is likely to be used.

cup of coffee in white mug on table


Bad coffee can taste like a few different things when it has gone bad. Dull and flavorless are the most commonly used terms to describe the taste of old coffee. Sour is another one. Coffee truly is one of those products that is exponentially better when it is fresh.

Time is a flavor thief when it comes to coffee. The diverse swirl of flavors you look forward to in your morning cup suddenly tastes more sour or have a bitter flavor. If that happens, let the coffee get cold and try it again. If the flavor is more bitter or sour than it normally is, the bag of coffee might be rancid.

Other ways

If you have allergies or maybe you are not fond of the idea of possibly drinking rancid coffee, I see you. There are other options.

Check the crema. When fresh beans are brewed, a thin layer of crema will form on the top. Thin black coffee with no microbubbles is a sign of old beans.

New beans have more carbon dioxide than old beans. Toss a handful of coffee beans into a baggy and remove the air. Seal it and leave it at room temperature overnight. If the bag puffs up, the beans are super fresh.

Coffee beans put out Co2 until they oxidize. If the beans have enough Co2 to puff the bag up, the beans are probably not older than 10 days. If the bag is still flat, the beans are older. This test does not necessarily indicate that the beans have gone bad, but it can give you an idea of which coffee beans you should drink first if you have more than one bag in the house.

What is the shelf life of coffee?

Coffee will produce the best flavor between one and three weeks after its roast date. You should be able to find the roasting date on the bag of coffee.

Espresso is between two and four weeks. Some coffee drinkers are choosier about taste. They will tell you that with each passing day, the beans lose more of their smell, flavor, and crema.

3 cups with coffee beans

How long the coffee beans last will depend on the type of coffee. Properly stored coffee will last longer. More on that topic later. For now, here is a guideline for how long coffee will last.

  • Whole coffee beans: 6-9 months
  • Ground coffee: 3-5 months
  • Instant coffee: 2-20 years.

As you can see, the type of beans matter. Whole beans will last longer than ground coffee while instant coffee will last a long time.

Read more: Instant Coffee vs Ground Coffee – what’s the difference?

There are always variables and exceptions to the rule. Many of the larger factory coffee bean roasters will prolong the expiration date by using nitrogen flushes. Freezing coffee can also prolong the expiration date, but it might affect the flavor.

How long does brewed coffee last?

If the coffee has already been brewed, it should be consumed within 12 hours for the best taste. If you want to get a few days out of it, storing it in the refrigerator will work, but be prepared for a slightly different flavor.

How to store coffee

The storage method of your coffee is also important. Coffee beans will last the longest if they are stored in an airtight container that will keep the coffee beans safe from any light.

coffee bean container

Your best bet is to keep the container in a cool, dark and dry place. This will keep the heat and moisture out of the beans and extend the life of your coffee.

Freezing coffee can be done, but just because one can do something does not mean they should. Freezing coffee can destroy the flavor of the beans. You have been warned.


What happens if you drink rancid coffee?

Most old coffee will not make you sick, but it absolutely can make you sick. If it is super old, it can cause you to have an upset stomach.
If dairy is involved in this situation in any way, food poisoning has the opening to slide right on in and make you miserable because of how fast it spoils. 

How long does it take for coffee to go rancid?

If you are an avid coffee drinker or coffee connoisseurs who never keeps a bag of coffee in the cabinet for longer than a couple of weeks, you are golden.

For anyone else, let’s chat about how long coffee can live at your house without going bad.

Whole bean coffee can last for a couple of months if stored properly in a cool place that’s dark. The flavor will start to decline after about a month, so consuming the delicious coffee before the four-week mark is the goal.

Ground coffee will go bad faster. It will go through the oxidation process faster once it is ground up. It’s a good idea to try to use the coffee within a few days of initially opening the bag, but it will last for a few weeks.

If you have already brewed coffee no matter if you brewed it in your coffee maker, Aeropress, Nespresso or any other way, drink it or dump it. Twelve hours is the deadline for brewed coffee.

aeropress coffee

Should coffee be refrigerated?

Coffee can be refrigerated, but it will not have as good of a flavor. You can stick brewed coffee in the fridge to extend its life for a couple of days, but you risk losing the good flavor.

Take this as an opportunity to show yourself some love and brew a fresh new pot of coffee instead of subjecting yourself to cold, sad coffee.

What to do with expired coffee?

If you have coffee that has gone bad, do not toss it out just yet. They can be used for baking, gardening, and more.

Baking – If your coffee beans have lost part of their flavor, but are not too old they can be used for cooking or baking. Brownies, tiramisu, cakes, and even meat rubs can use coffee in their recipes.

Gardening – ground coffee makes great fertilizer. It adds essential nutrients to the soil which promotes plant growth and attracts worms. That’s a good thing, I promise. (Head here for even more plant fun!)

Insect Repellent – Mosquitoes and some other pests avoid coffee because it has compounds that are dangerous to them. Sprinkle some ground coffee beans around an outdoor seating area to deter pests.

Skin Care – Mix coffee grounds and coconut oil together and you have yourself a cheap, effective, and deliciously-smelling body scrub. This mixture will remove dirt and dead skin cells while also moisturizing the body. You can also make lip masks!

Final Thoughts

Don’t let coffee go bad. Life is too short to drink bad coffee. You are now equipped with several ways to make sure the coffee you are drinking is of the best quality.

The best way to determine if coffee is rancid is to smell it. If the coffee gives off fragrances like mildew or ash, dump it out. Keep the coffee stored in an airtight container, in a cool area, away from light.

Looking for more coffee fun? Head on over to one of these expert coffee guides!

About bit of cream

Rishi and Jen are the creators behind Bit of Cream. They start each morning with a cup of coffee and are on the hunt to make that simple cup of caffeine better and brighter. Feel free to send them a message or follow along on Instagram!

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