Does Ground Coffee Lose Caffeine Over Time


Some people enjoy crafting their morning coffee with the delicacy and finesse of a barista. Others (like myself) must drag themselves into the kitchen with barely enough cognitive thought to place the filter.

I’m not a morning person. No matter the process, our goal is the same. We are catching a ride on that sweet, embracing, delectable caffeine train.

Caffeine is everything we love about the daily grind.

Many folks stock up on the stuff to prevent a morning crisis by running out of a coffee (que blood-curdling scream). This has led people to wonder, “Will my coffee go bad if it sits too long?”.

The short answer is no. The flavors and oil may take a hike, but the caffeine will stay potent for years.

But it’s not quite as simple as that for some surprising reasons. Let’s look into: does coffee lose potency?

Does Ground Coffee Lose Caffeine Unbrewed Over Time?

old ground coffee
Old Ground Coffee Doesn’t Lose Caffeine.

It takes a very long time for coffee to lose its potency. To better grasp this, it’s beneficial to understand caffeine as a chemical.

As we all know, caffeine is the delicious diesel fuel that charges through our central nervous system after our morning coffee. This chemical is naturally occurring in various food products.

But most importantly,…coffee.

Caffeine is a very stable and resilient chemical, especially compared to other naturally occurring chemicals in food.

It’s water-soluble (which means it easily dissolves) and is the last compound to be extracted when brewing delicious java.

If you want to deep dive into solubles related to coffee, we go into it in our article about Why Coffee Beans are Oily.

When coffee is exposed to the air, its quality slowly begins to degrade in a process known as oxidation. But this doesn’t speak to its caffeine potency.

Although the oils and general flavor will start to evaporate, the caffeine will hold its ground and maintain its kick.

Keep in mind that the older your coffee is, the more bitter it will be.

This issue with older grounds lies more with flavor rather than quality and effectiveness. Your unbrewed grounds will still provide you with an energy boost, but your hot cup of joe might not taste as good as it could.

The Best Way of Preventing Your Coffee Beans From Going Stale

How do you make your coffee taste as fresh as possible? You might be tempted to buy a new bag of beans every week, but this is not the best way. The longer that your coffee beans are exposed to oxygen, the more they will go stale. Learn how to prevent this from happening with these tips!

  • Store Your Coffee Beans in an Air Tight Container: If you store your coffee beans in an airtight container and properly sealed them, they should stay fresher for up to 12 months or even longer. This means that if you have any leftover grounds at home after using them in a recipe or two, put them into an airtight jar until next time, so they don’t get too old – better yet, grind your coffee beans right before brewing coffee, so they don’t go stale.
  • Don’t Store Your Coffee Beans Near Heat Sources: If you’re storing your coffee beans in a bag or container that’s near any heat source, it will cause the beans to go stale quicker than if they were stored away from them. This means that when you store your coffee at home, make sure not to leave them anywhere near an oven or stove. Remember not to keep your coffee on top of your refrigerator as well. This is also true for keeping them on the countertop as well.
  • Keep Your Whole Bean Coffee and Ground Coffee Separated: When whole bean coffee and ground coffees are mixed, then one of two things can happen; either both types of grounds get old faster because their flavors intermingle, which allows oxygen to permeate to the whole beans damaging them more quickly, or the ground coffee will absorb all of the oxygen which then makes it harder for you to get fully fresh whole beans.

What Air Tight Container Is the Best?

This one from Veken is a great air tight coffee canister.

Coffee Canister

For coffee lovers, freshness is everything, and when it comes to storing your favorite beans, you want something that will keep them fresh and free of harmful oxidation. Veken Coffee Canister’s thick stainless steel container with a one-way carbon dioxide valve and 100% BPA-free silicone rubber seal keeps air out, preventing the growth of mold or other harmful bacteria.

I also like the date tracker on the lid. This lets you set storage or expiry dates for your coffee, so you can always enjoy it at its freshest date.

I recommended taking a look at my article that is dedicated entirely to preserving coffee. Tips To Storing Coffee the Right Way!

How to store coffee

How Quickly Does Coffee Lose its Caffeine

As stated above, caffeine will last longer than any other compound in coffee—the sole survivor.

If coffee is appropriately stored inside an airtight container in a dark, dry space, it will take roughly four years for caffeine to lose any potency.

Keep in mind that various factors affect this, such as the quality of the coffee but overall, coffee won’t lose its effectiveness.

cold coffee doesn't loose caffeine

If you want your coffee to last, always buy whole beans. They keep much better than grounds and take much longer to oxidize and become stale. As soon as a coffee bean is ground, it begins losing its natural oils. Whole beans will retain these components much more proficiently.

It’s good practice to only buy whole beans and grind them right before that sacred brew time.

We talk about the perfect coffee grinding times in our article, How Often To Grind Coffee Beans.

How Often to Grind Coffee

Does Coffee Lose Its Caffeine When Refrigerated?

Some of us have hectic schedules that won’t even allow time to prepare that magical nectar that gets us through the day. (I hope you didn’t think about whiskey when I said that).

If that sounds like you, you probably prepare your coffee the day before and throw it in the fridge. Although I recommend you grind your coffee beans right before use, you have to work around your schedule the best you can.

Well, the good news is, it doesn’t lose any caffeine when chilled!

You will lose a little flavor. Appropriately chilling and storing coffee helps conserve the natural oils. Caffeine is not known to evaporate when chilled, and caffeine is the main topic of this article; that’s why I’m not focusing on flavor when storing coffee in the refrigerator.

You want to avoid refrigerating your coffee with sugar or cream. Not only does it keep better riding solo, but the sugar and dairy may curdle if you decide to warm it up.

When refrigerating coffee, it’s always best to use an air-tight glass container. A plastic container may warp and lose its seal, while metal containers react with the coffee’s acidity providing a metallic taste.

It’s recommended to drink refrigerated coffee within a 3-to-4-day window.

But that also depends on which coffee you’re using. The good old smell and sight test should do. Use your best judgment.

Now you may have issues with re-heating your coffee, but we’ll get to that later.

Believe it or not, refrigerating raw coffee grounds is known to preserve them better. The grounds themselves don’t actually freeze, so they are ready to go at a moment’s notice.

Do Old Coffee Grounds Have Less Caffeine?

As we discussed before, caffeine is incredibly resilient. It is a very stable chemical that will outlast everything else in coffee before it begins to diminish, which can take years.

If you brewed up an old bag of coffee, you’d still feel a good kick!

It just might not be that delicious cup of joe you’re used to.

Believe it or not, caffeine is so prominent that you could brew coffee from previously used grounds and still get a jolt of motivation. This is due to the brewing process.

caffeine in old coffee grounds
It’s Not Recommended to Use Old Coffee Grounds but There Is Still Caffeine in It.

When brewing, caffeine is the last thing to be siphoned from the grounds. Because of this, large amounts of caffeine remain in the used grounds.

Now I have to say, as a coffee lover, I do not recommend brewing coffee with used grounds. When used grounds are brewed, the only thing left is caffeine, which is very bitter.

unless you’re in a real pinch, don’t do that to yourself.

What if You Reheat Your Cup of Coffee?

Well, here you are, you brewed too much coffee AGAIN.

I do this very often. I overcompensate how big of a pot to brew in the morning and fail to finish it before leaving for work.

If you’re like me, it breaks your heart to pour coffee into the drain and waste it. So how does it fare when re-heated?

reheat coffee in microwave will keep its caffeine
Reheating Coffee in the Microwave Will Not Reduce Its Caffeine

When you heat up coffee, the remaining components, except for caffeine, will evaporate. So, if you microwave a cup of coffee, you’re still going to receive a kick from the caffeine. Just don’t expect it to be the most flavorful coffee you’ve ever had.

If possible, avoid the microwave and use a stovetop to bring the temp back up slowly. This helps conserve flavor.

Be careful warming coffee with dairy products. You don’t want to risk the cream curdling.

Does Boiling Coffee Remove Caffeine

If you’ve got down this far you’ve noticed a common coffee theme. It’s that caffeine is tough and will be the last thing in the cup of coffee after everything has evaporated away.

So no, boiling coffee does not remove caffeine from it.

What boiling water does do to coffee is that it pulls out the solubles from the grounds. This process is best done between 195 to 205 degrees Fahrenheit. The solubles will continue to oxidize as the brewed coffee cools, giving hot coffee more of a sour and bitter taste.

Wrapping Up

Even if we’ve seen that caffeine will stay in coffee in just about every situation, being years old or boiled down, you might find it better to through the old stuff out and open a new bag.

Fresh coffee will undoubtedly taste better than the old stuff sitting in the cupboard for years and years.

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