All out of fresh coffee? However, on a frantic hunt, you’ve managed to unearth an old dusty bag of coffee from the back of your cupboard.
You’re not sure how long it’s been sitting there; a thought crosses your mind, does coffee lose caffeine?
Common sense dictates that brewed coffee won’t stay great-tasting forever, but if the coffee hasn’t been brewed or even ground yet, will it still have the same amount of caffeine and taste just as fresh?
In this article, I’m going to answer those questions and more. By the time you reach the end, you’ll know if whole bean, ground, and brewed coffee still retains the same caffeine levels once the clock starts ticking.
A Closer Look At Coffee Freshness
Before we look at how caffeine deteriorates in coffee over time, it’s probably a good idea to understand how coffee loses its freshness.
Green coffee beans, once dried, can be stored for months or even years under the right conditions.
A good analogy is to compare coffee with how we look at bread. Think of the flour as green coffee beans, the loaf of bread the roasted coffee bean, and sliced bread as the ground coffee.
Flour can be stored for up to 2 to 3 years however, once that flour has been turned into a loaf of bread, it’s good for only a week and even less once it’s been sliced.
So essentially, what I’m trying to say is that dried green coffee beans have a long shelf, but as soon they’re roasted, the clock starts ticking and rapidly speeds up once ground.
Ideally, once roasted, whole coffee should be consumed within a couple of weeks for peak freshness and flavor.
The older coffee gets, it starts to lose a lot of its flavor compounds (volatile organic compounds), and your coffee won’t taste as good as it should.
However, caffeine isn’t one of those compounds; it stays in the bean.
💡 Fun Fact: Decaffeinated coffee isn’t entirely caffeine-free. On average, it typically retains about 3 mg of caffeine per cup but can range from 0 to 7 mg.
Does Coffee Lose Caffeine? Whole Bean, Ground, & Brewed
For a second, let’s forget about that dusty old bag of expired coffee you discovered, and let’s focus on the different stages of coffee from start to finish and the amount of caffeine the coffee holds.
The facts might surprise you.
Whole Coffee Bean
Fresh roast whole bean coffee, generally speaking, doesn’t lose a noticeable amount of its caffeine content.
However, some would argue that high temperatures during the roasting process cause the caffeine to evaporate. But that’s debatable, and even if true, it would be tiny amounts that wouldn’t make much of a difference.
If we’re talking about whole bean coffee you’ve just purchased from your local roaster, it will not lose any caffeine when stored correctly at home.
The flavor will start to deteriorate the longer they are kept as the compounds break down due to oxidation, but caffeine levels will stay the same.
You may think that the caffeine will quickly dissipate once the coffee has been ground. Wrong.
Even when ground the coffee won’t rapidly start to lose caffeine. With coffee grounds, the only thing you should worry about is oxidation and the loss of flavor and antioxidants.
Ideally, you should grind your whole bean coffee right before you intend on using it; you’re guaranteed a great-tasting cup.
💡 Fun Fact: Caffeine levels in one cup of coffee are about 100 to 200 mg, a cup of tea typically has no more than 70 mg, and most sodas contain less than 50 mg.
Caffeine does not evaporate or disappear after brewing, so even brewed coffee will retain its caffeine levels almost indefinitely. And there will be just as much caffeine in your coffee after 6 hours as there was after only a few seconds of it being brewed.
In fact, some may argue that the coffee will have slightly higher amounts of caffeine due to the water evaporating.
If you’re concerned about how your coffee tastes, then brewed coffee will last for roughly 25 minutes at room temperature without the flavor being undermined.
After a couple of hours, apart from losing their aromatic compounds, old coffee beans will begin to develop unpleasant flavors and a bitter taste.
If you’re worried if your coffee will lose its caffeine over time, then don’t. Caffeine is actually a very stable compound, and it doesn’t degrade quickly. Whole beans, ground or brewed, will keep the same amount of caffeine for a long time.
Indefinitely, I doubt it. Even in the pharmaceutical world, caffeine as a dry chemical has a shelf life of around four years before any significant changes occur, and caffeine in a solution can be stable for up to several years at cool temperatures.
But when it comes to that dusty old bag of coffee at the back of your cupboard, I’m confident the caffeine levels will still be the same as when it was first packaged. The flavor and freshness, on the other hand, are a whole different story.
🏷️ Related: Best Coffee Canisters For Storage And Freshness!
🏷️ Related: How Long Do Green Coffee Beans Last?
🏷️ Related: Does Coffee Go Bad? (The Shelf Life Facts)
📌 Does Coffee Lose Caffeine When Reheated?
Reheating your brewed coffee will not cause it to lose caffeine. Caffeine is a pretty stable molecule, and they are unlikely to change when cooled or reheated.
However, caffeine can break down in its soluble form if turned into vapor, and for that to happen, you would have to heat your coffee to over 350°F.
I suggest reheating your coffee in the microwave at lower temperatures rather than on the stovetop, so you don’t accidentally destroy the caffeine in your coffee.
📌 Does Coffee Lose Caffeine When Microwaved?
No caffeine won’t be lost if you reheat your coffee using the microwave. However, the flavor of the coffee might degrade, and that once tasty cup might not be so delicious.
So if you enjoy an overly bitter and burnt-tasting brew, go ahead and reheat your leftover coffee.
📌 Does Coffee Lose Its Potency Over Time?
If you’re talking about flavor and freshness, then yes, coffee grounds will start to degrade within only a few hours of being exposed to oxygen and the environment.
But, if you’re talking about the amount of caffeine, then no. Caffeine is a much more stable chemical that can last for months or even years without any significant impact on its potency.