Does Coffee Lose Caffeine Over Time? Here Is The Answer

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We, coffee lovers, are sometimes too busy to enjoy our coffee when it’s still warm or pay enough attention to preserve our grounds. With time, taste and flavor change, definitely not for the better. But how about caffeine? Does coffee lose caffeine over time?

Does Coffee Lose Caffeine Over Time?

The answer is No. Caffeine doesn’t evaporate when exposed to the air, but oxidation can cause the flavor of coffee to be degraded. Caffeine is a fairly stable compound and can last for a long time and still retain its inherent properties. Unless you want to remove the caffeine from the beans to turn it into a decaf version.

There is a false assumption that old coffee beans become dull and lose their caffeine content with time. However, the truth is that they still retain a nearly equivalent amount of caffeine as the freshly-roasted beans do.

Coffee loses its flavor over time, depending on its form. Beans lose their flavor the slowest, while coffee grounds will be more susceptible to oxidation and lose flavor more quickly. 

To limit the loss of flavor in coffee over time, people consider using different preservation methods. Still, the most important thing is to prevent the contact of coffee beans with oxygen.

The question above is the same as what most people often ask: “Does espresso lose caffeine over time?”. The answer for both is No.

What Is Caffeine In Coffee?

Caffeine is a natural stimulant found in more than 60 plants, including coffee beans, tea leaves, and cocoa pods. They work by stimulating the brain and central nervous system, keeping people awake, and preventing fatigue.

Caffeine has a white color and a bitter taste. It is solid, non-volatile, but soluble in water. Therefore, when coffee evaporates, only the water evaporates, and the caffeine remains intact in the cup.

According to the US Food and Drug Administration – FDA, caffeine is considered both a food additive and a drug. The FDA also warns that we should not abuse coffee as a source of caffeine because overconsumption can adversely affect our health.

How Does Caffeine Affect The Taste Of Coffee?

It is useful to know how to detect caffeine in coffee to judge its quality. You perhaps don’t want a cup of coffee that is incapable of keeping you awake, do you?

Bitter Taste

Since caffeine significantly contributes to the bitterness in coffee, how bitter the brew is can suggest the caffeine content present to some extent. 

Fragrance

Relying on a fragrance to judge the quality of coffee requires a great sense of smell. But caffeine does not affect the taste of coffee.

Coffee that has been around for a long time since it was roasted or oxidized is often less aromatic or even smells slightly foul. However, each coffee type has a different aroma, so you need to have a certain understanding of coffee for successful detection.

Color

New coffee beans will have a distinct brown color, and the color of the dull one is so different that you can notice the first time checking. But one thing is for sure, the amount of caffeine between them is constant. If you find it difficult, go to reputable coffee shops to ensure the quality of coffee you desire.

Coffee Types & Brewing Methods

There are different amounts of caffeine in different coffee types. For example, Arabica coffee has only 1.5% caffeine content while Robusta beans have 2.7% pure caffeine.

Regarding the brewing method, filter coffee generally contains a higher amount of caffeine as the slower brewing process allows more caffeine to be extracted. This means that both filter and drip coffee will have a higher caffeine content than espresso.

How To Preserve Caffeine In Coffee?

Preventing coffee from losing caffeine is similar to preserving the flavor and taste for the best brew. 

Zip Bags/Airtight Containers

A sealed or airtight container is a great way to keep the caffeine content in coffee beans/grounds from dwindling. However, neither zip bags nor airtight containers are 100% sealed. 

They only slow down the coffee’s oxidation as much as possible, so coffee kept in these items will eventually lose its caffeine over an extended period.

Nitrogen Flushing

Nitrogen flushing is one of the most effective ways to preserve coffee. Flushing out oxygen from your bag can save the taste, freshness and maintain the caffeine content. 

However, the high cost and complicated preservation process are slightly off-putting for many people. Therefore, nitrogen preservation is only for businesses that sell coffee in large quantities.

Use Coffee Regularly

Many coffee lovers recommend brewing coffee frequently, so you won’t let your coffee sit idle for a long time and lose all the finest taste, flavor, and possibly caffeine. 

If you are a frequent coffee drinker, then you only need an airtight container. It will keep the coffee beans in good condition, and you can grind the right amount to suit your drinking needs.

With regular coffee use and an airtight container, you don’t have to worry about the loss of caffeine content over time.

Read more:

How To Reduce Caffeine In Coffee?

Decaf Coffee

Decaf coffee is the ideal choice when you still want to enjoy the taste of coffee without experiencing the stimulant effects of caffeine. In the making of decaf coffee, at least 97% of the caffeine is removed before roasting and grinding.

Brewing Temperature

You can lower the brewing temperature (via water temperature) to cut down on the volume of caffeine. It is because caffeine is highly soluble at high temperatures. 

Therefore, let’s use the cold-brewing method or room-temperature water to brew coffee if you want less caffeine. You’ll get less caffeine out of the coffee beans and into your cup.

Arabica Coffee Beans

As mentioned above, Arabica is fairly low in caffeine, at only 1.5%. Therefore, you can choose Arabica coffee if you want to cut back on caffeine intake.

Amounts Of Coffee Grounds

You can adjust the amount of ground coffee to lessen the amount of caffeine. However, this might compromise the quality of your brew. If you cut down on the coffee grounds, keep in mind to use less water to brew to keep the optimal flavor.

Brew Time

Caffeine dissolves in water, so you can adjust the brew time to reduce it. Accordingly, the shorter the brewing time, the less caffeine ending up in your cup.

However, it doesn’t mean espresso will have less caffeine than other coffee types. You should pay attention that it’s all about shortening brewing time, not switching to other methods requiring less brew time. 

Brewing Method

How you brew your coffee can greatly affect the caffeine content ending up in your cup. With the espresso method, hot water continuously flows into coffee in a short time, meaning that the caffeine has less time to be extracted into the brew. 

On the other hand, you will need to wait for the coffee to drip slowly with the dripping method. The extended extraction means that more caffeine will come out from the beans.

As a result, caffeine per serving in espresso and filter coffee is significantly different.

Dark Roasted Coffee

The longer the roasting, the more caffeine is lost. Thus, using dark roasted coffee is one of the easy ways to bring down caffeine. It’s worth mentioning that the darker the roasts, the more bitter and burnt flavor you have.

Frequently Asked Questions

Does Coffee Lose Caffeine When Reheating?

Caffeine is a non-volatile substance, so when you reheat the coffee, only the water evaporates, and the caffeine remains in the cup. 

Since the melting point of caffeine is at 460 degrees F, brewing or reheating cannot alter any amount of caffeine (the highest water temperature is at 212 degrees F). Reheating coffee will only ruin the aroma and taste of the coffee.

Is Caffeine Lower When You Reuse Coffee Grounds?

Yes, it is. The caffeine in used coffee grounds partly dissolves into the water during the first brew. As a result, you’ll have less of this stimulant in your cup when you recycle the coffee grounds. 

However, the amount of caffeine coming out of the second brew is still quite significant. After the first use, coffee grounds can produce a caffeine content of about 3.59 – 8.09 mg per one gram of coffee. Meanwhile, Arabica coffee grounds can produce 12 mg of caffeine, and it is 22mg for Robusta.

The amount of caffeine in the second brewing also depends on the chosen brewing method. As you apply the above methods of reducing caffeine, the reused coffee grounds will produce less caffeine than casual. 

On the other hand, we do not recommend brewing your coffee grounds twice because the aroma and taste are not as good as the first time.

Final Thoughts

Does coffee lose caffeine over time? No. If you accidentally let the coffee beans sit in water for a long time, there is a chance that only a small part of the caffeine will relatively vanish and those coffee beans are not suitable for brewing

However, caffeine can stay in your coffee grounds/cups for quite a long time if kept in airtight containers. This means that you still enjoy that much-needed energy boost yet with reduced taste and flavor.

Related articles: Does adding milk to coffee reduce caffeine?

Almost 20 years already spent committed to coffee and more than 3 years of experience as a barista at Starbucks. I graduated with a Bachelor’s Degree in Nutritional Science from the University of California, Berkeley. And then, I finished the Coffee Skills Program at the Specialty Coffee Association (SCA). ugvermont.com is a website that I dedicate my whole heart to sharing all knowledge related to coffee. Read more