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Do Coffee Grounds Go Bad?

Some people prefer to store fresh grounds to last them several brews instead of waking up to the noise of a grinder. Are you one of them?

It saves time, plus you can make as many cups as you'd like as the grounds are there waiting for you to pour into a coffee machine.

Therefore, do coffee grounds go bad?

Yes, they do. Like everything else, coffee grounds have an expiration date. Of course, the storage conditions matter. On top of that, when you open a bag of coffee grounds, the shelf life decreases faster than for an unopened bag.

Let's talk more below.

How Long Can You Keep Coffee Grounds?

When you store fresh grounds without freezing them in a vacuum-sealed container, they last up to three weeks. That's way below the 20-year shelf life of instant coffee stored in optimal storage conditions. Why?

coffee grounds in a jar and spoon

Elements like air, light, heat, and moisture change the flavor and quality of coffee grounds. Your kitchen and pantry have all of these elements, and the more these elements reach your coffee grounds, the faster your coffee loses flavor. 

When you store coffee grounds at a temperature of over 86° Fahrenheit or in a container that is not airtight, it lets in oxygen, and oxidation starts. It extracts the flavor from the coffee grounds, diminishing their freshness over time. The situation gets worse when you open and close the container every day, allowing more elements inside.

When you store coffee grounds in a refrigerator, they'll also go bad fast as the temperature in a fridge fluctuates often. However, when you freeze coffee grounds in a vacuum bag, they last up to two years. 

If the container isn't vacuum-sealed, the flavor lasts about six months when you freeze them. They have a similar shelf life when you store them in a pantry and still use a vacuum-sealed container.

How to Tell If Coffee Grounds Are Bad

man smelling ground coffee in a glass

Open the container and smell the coffee grounds in it. Bring a spoonful of the contents to your nose, and if the coffee grounds are fresh, they'll have a pleasant, caramel aroma. On the other hand, if they have a dull and even dusty smell, you might want to grind new beans.

Coffee grounds left in a container on a kitchen counter may be moldy due to moisture. Therefore, you can open the jar and inspect them as you scoop spoonfuls. When you mistakenly leave the lid open for days or notice that it doesn't seal completely, it's enough for you to inspect the contents inside for mold.

When you brew such grounds, they'll taste flat, moldy, or bitter. These smells and tastes vary with the roast and the brand, but you'll always tell when it's time to throw your coffee grounds. If you have some beans left, smell them too as days go by to avoid grinding stale beans.

Does Brewed Coffee Go Bad?

pot with brewed coffee

Coffee flavor changes gradually from about 30 minutes after you brew it. In the next four hours, the oils in it acquire a different taste due to oxidation. The process is faster when there are additives in it, such as milk. 

However, if you don't refrigerate it, black coffee is safe to drink in the next 24 hour hours after brewing. When you store it in a refrigerator as soon as possible, you can drink it in the next four days. It's not advisable to refrigerate a brew with milk, but it lasts about two days. 

The best solution here is to brew enough for an hour, then make some later. You can store the excess in a coffee mug with a tight seal, but its taste will still change gradually.

Storage Tips to Extend Shelf Life of Your Ground Coffee

There are a few things you can do to avoid wasting coffee grounds. Let's discuss such solutions.

Change the Container

Store your coffee grounds in an opaque container instead of a transparent one to minimize contact with light. A transparent jar looks attractive, especially on your kitchen counter, but it has to go. 

Alternatively, you can have one for coffee grounds you'll use the following day and another to store a month's supply in the pantry. It should also have an airtight seal. 

You can also package it in small containers in quantities needed per day or week. That would prevent the need to open a jar to scoop some coffee while exposing the remainder to elements like air. 

You can also place them inside a resealable bag in their original packaging and squeeze the air out before sealing the bag.

Store Coffee Grounds in a Dark, Dry Place

They need a dark, dry storage area of the pantry or a kitchen cupboard. Thus, your kitchen counter isn't a good place to leave your coffee grounds, no matter how convenient it is for you.

Buy Coffee Beans in Small Quantities

You're in more control of the quality when you buy coffee beans instead of coffee grounds. It's the only way to tell how long the grounds have been on a shelf. Plus, you are sure of the roast quality and flavor before storage. 

Buy smaller packets of coffee beans so that you don't keep them for too long, grind them, and store them again for months. If you must buy them in bulk, freeze them. 

Grind Enough, Not Too Much

Grind enough for use so you can store the rest as coffee beans to maintain their flavor. If you must do it all at once, grind what you can consume in two weeks to enjoy a flavorful cup every time. Do it as close to the brewing day as you can. 

Freeze Coffee Grounds

Freezing is an option when you have more than you can consume in a month. Don't store your coffee grounds in a refrigerator as they'll lose moisture and absorb smells from other items. 

Further, when you freeze all your coffee grounds, you risk increasing moisture content every day you take the container out of the freezer. The spoon used can also introduce moisture to dry coffee grounds.

Risks When Consuming Expired Ground Coffee

Unless the grounds are moldy, there is a minor health risk when you consume them. The most you'll miss is the flavorful, appealing aroma. But, you can only use coffee that was in a sealed, airtight container. It's also a different case when the grounds have other ingredients that may increase the risk of contamination, such as creamer.

Also, note that mold in coffee grounds can trigger an allergic reaction, so be wary of leaving them at room temperature.

Creative and Safe Ways to Use Expired Ground Coffee

There are so many uses of stale coffee grounds when you don't want to brew them. Let's look at a few options.

To Remove Odor

One of the first uses of coffee grounds is freshening up the air in your home. Pour the coffee grounds into a bowl and leave them in the room with an odor overnight. Shut the windows too so that the coffee grounds work on the air already in the room. 

In the morning, take them out, leaving your interior fresh. It takes away even odor in clothes, shoes, and bags.

As an Exfoliator

If it has been a while since you gave your body a good scrub, coffee grounds can help you do that. Pour some water on the coffee grounds to form a paste, then apply it to your body. 

You could also make a scented body scrub by adding your favorite natural oil, such as almond oil.

Use Them in Your Kitchen Garden

A compost bin containing coffee grounds is rich in nitrogen, magnesium, calcium, among other nutrients. It can boost the nutrients in your soil after a harvest faster and safer than artificial fertilizers. What's more, coffee grounds clean up the soil by absorbing contaminants like heavy metals.

You can grow mushrooms, carrots, cabbage, and radish in such soil. That's a complete kitchen garden. 

As for the coffee filter, find out here if you can it to the compost bin. 

As an Insect Repellent

Use coffee grounds instead of bug repellents that may harm your respiratory system. They fight bugs like mosquitoes and fruit flies. Sprinkle the stale coffee grounds on your plants or in the backyard, and you'll keep so many bugs away. 

In Cleaning

Finely ground coffee may not help you in this task, but if you can get some coarse grounds, they'll leave your pots sparkless. It's a solution for those sooty camping pans that need scrubbing. 

If you have several pounds of stale coffee grounds, how about cleaning your fireplace? Pour them on the ashes to keep the dust down as you clean the area.

Final Thoughts

Coffee grounds contain oils, amino acids, and other compounds. These break down through various chemical processes, so the flavor changes the longer you store your coffee grounds. 

The process is faster when you grind stale coffee beans. 

But, you can boost the shelf life of your coffee grounds by limiting their contact with air, moisture, heat, and light. Store your coffee grounds in a dry, dark place in an airtight container. It's the only way to make sure your coffee tastes like coffee.

Krista Haws

Known among her friends as 'the caffeine fiend', Krista loves all things coffee. From an extremely short, strong espresso to a 3 day cold brew, Krista loves them all.

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