Key Takeaway
- Decaf coffee contains up to 5 mg of caffeine per 8 oz cup, so for most people it won’t disrupt sleep—though brewing method, bean type, and individual sensitivity can still make you feel more awake.
Different coffeenatics have varying coffee preferences. Most people like it strong and bold, while others prefer it light and weak. Another subset of drinkers is the decaf crowd.
Will decaf coffee keep you awake? If you’re craving the taste of coffee but worry about midnight jitters, you’re not alone—many home baristas ask whether decaffeinated brews still pack enough caffeine to keep them tossing and turning.
Decaffeinated coffee is a popular choice for people who want the taste of coffee without all the jitters and caffeine buzz that comes with drinking a regular cup. Decaf is made by removing at least 97% of caffeine from green beans through methods like water processing, COâ‚‚ extraction, or solvents (Starbucks Coffee at Home, n.d.; National Coffee Association, 2024).
But is it possible that these same people are unintentionally courting sleepiness by drinking decaf?
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The answer is a little complicated. This article will give you a better idea of whether or not decaf can keep you awake or not.
What’s up with Decaf?
Some people like coffee that is strong and has a lot of caffeine in it. Other people like weak coffee that doesn’t have as much caffeine. The third kind of person likes coffee that doesn’t have any caffeine in it. This kind of coffee is called decaf.
So does drinking decaf coffee mean you will be more likely to wake up in the middle of the night? Well, it’s not quite that simple.
Decaffeination Methods & Residual Caffeine
Swiss-Water Process: A chemical-free water method removing > 99% of caffeine, leaving typically < 3 mg per 8 oz cup (Swiss Water, 2023).
CO₂ Process: Uses supercritical CO₂ to extract caffeine, leaving 1–5 mg (Swiss Water, 2023).
Solvent-Based Processes: Employs ethyl acetate or methylene chloride, removing ~97–99% of caffeine; residual levels can reach 2–7 mg (National Coffee Association, 2024).
These residual amounts explain why decaf still contains trace caffeine.
Factors Affecting the Amount of Caffeine in Coffee
A few factors can influence the amount of caffeine in your cup of joe, and how good or bad it is for keeping you awake.
Coffee Beans Used
One factor influencing how much caffeine is in your coffee is the type of beans used to make it. Different types of beans have different amounts of caffeine. Decaf from one brand might have less caffeine than another brand.
Robusta beans average 2.2% caffeine by weight, Arabica about 1.2%—even after decaf processing, Robusta-based decafs can contain more residual caffeine (Juliano & Griffiths, 2006). Decaf from one brand might have less caffeine than another brand (Goodson, 2018).
For example, some decaf coffees use Robusta beans, which are naturally higher in caffeine than Arabica beans. If you get a cup of decaf coffee made from Robusta beans, it may have more caffeine than a cup of similar-tasting Arabica-based decaf.
Brewing Time
How long you brew the coffee also affects how much caffeine it contains. The longer you brew the coffee, the more caffeine you extract from the coffee grounds. Therefore, if you make your coffee for a shorter time, there will be less caffeine in your final drink.
So if you brew your decaf coffee for a long time, it may have more caffeine than if you brew it for a shorter period. However, this is usually not the case with regular coffee since most people don’t typically let their coffees steep for very long.
Short steep (2–3 min): ~2 mg caffeine
Long steep (5+ min): ~4–5 mg caffeine (Goodson, 2018)
Other Factors
Some other factors can influence how much caffeine is in your decaf coffee, including how much you dilute your brew and whether or not you add cream or sugar to it.
How Much Caffeine Is in Decaf Coffee?
At the end of the day, decaf coffee is still a drink that contains caffeine. Although it may have less caffeine than regular coffee, most cups of decaf will still contain some amount of this stimulant.
Regular coffee has 100+ mg of caffeine per 8 oz cup, and decaf coffee typically contains 2–7 mg per cup (Goodson, 2018; Juliano & Griffiths, 2006). This means that decaf coffee should help you stay awake and alert if you have no medical condition that makes your body more sensitive to caffeine.
The ADORA2A Gene
Many experts remain fascinated with people who possess the ADORA2A gene. Many associate the ADORA2A gene with caffeine consumption and general wakefulness. People with this gene might find that they sleep better after consuming a cup or two of decaf coffee, as opposed to regular coffee drinkers without the same genetic makeup.
So while it’s not guaranteed that you will doze off at night if you drink decaf coffee, it’s clear that there are many factors at play when it comes to how much caffeine ends up in your cup. And if you have the ADORA2A gene, it may be worth experimenting with decaf coffee instead of regular coffee to see if you sleep better!
The Psychosomatic Effect of Drinking Coffee
Drinking coffee is a controversial topic these days. Some people believe it can have profound health benefits, while others think too much coffee can harm your overall well-being.
Some evidence suggests that drinking coffee may influence how well you sleep at night. This is known as the psychosomatic effect of coffee, which is the idea that what you eat and drink can affect your health on a psychological level.
If you feel like drinking decaf coffee makes you awake, remember to take a closer look at your nighttime routine. The following can also be culprits to your late-night alertness:
- the amount of light in your bedroom
- the temperature of your bedroom
- your caffeine consumption during the day
- your eating habits throughout the day
- how much time you spend on electronic devices before going to bed
So, Will Decaf Coffee Keep You Awake?
In general, decaf coffee can keep you alert and stay awake during the day. However, several factors may influence how much caffeine ends up in your cup. These include your genetic makeup and other lifestyle habits.
If you feel like drinking decaf coffee makes you more awake at night, it may be worth experimenting with different factors to see which ones make the biggest difference. For any concerns about your caffeine intake or general sleep quality, speak with your doctor.
Final Thoughts
Decaf coffee can be a great way to stay alert and energized during the day. If you want to enjoy your decaf coffee without worrying about it keeping you up at night, there are several different factors that you can experiment with. These include your caffeine consumption during the day, your eating habits, and your sleep routine overall.
So go ahead and enjoy that cup of decaf – just keep in mind that it still contains some caffeine. Be sure to listen to what your body is telling you and do what works best for you!
References
Goodson, A. (2018, September 15). How much caffeine is in decaf coffee? Healthline. https://www.healthline.com/nutrition/caffeine-in-decaf
Juliano, L. M., & Griffiths, R. R. (2006). Caffeine content of decaffeinated coffee. Food Chemistry, 99(2), 452–455. https://pubmed.ncbi.nlm.nih.gov/17132260/
National Coffee Association. (2024, December 6). Decaf coffee. https://www.aboutcoffee.org/beans/decaf-coffee/
Starbucks Coffee at Home. (n.d.). What is decaffeinated coffee? https://athome.starbucks.com/learn/what-is-decaffeinated-coffee
Swiss Water. (2023, January 23). How much caffeine is in decaf? https://www.swisswater.com/blogs/sw/how-much-caffeine-is-in-decaf
