Decaf coffee is not completely caffeine-free. While it has at least 97% of caffeine removed, virtually all decaf coffees still have about 7 mg per 8-ounce (236-ml) cup.

Coffee is one of the most popular beverages in the world.

While many drink coffee to gain increased mental alertness and energy from its caffeine content, some prefer to avoid caffeine (1, 2).

For those who are caffeine-sensitive or looking to reduce their caffeine intake, decaffeinated, or decaf, coffee can be a great alternative if you don’t want to give up on coffee’s delicious taste entirely.

However, decaf coffee still provides caffeine.

This article reviews how decaf coffee is made and how much caffeine your decaf cup of joe may hold.

Decaf coffee is not completely caffeine-free.

While USDA regulations stipulate that decaf should not exceed 0.10 percent caffeine on a dry basis in the package, comparison between brewed regular and decaf coffee shows that decaf appears to have at least 97% of caffeine removed (3, 4, 5).

To put this into perspective, an average 12-ounce (354-ml) cup of coffee containing 180 mg of caffeine would have about 5.4 mg of caffeine in a decaffeinated state.

Caffeine content in decaf coffee depends on the type of bean and the decaffeination process.

Decaf coffee beans are typically made by one of three methods, using either water, organic solvents or carbon dioxide to draw caffeine out of the coffee beans (6).

All methods soak or steam green, unroasted coffee beans until the caffeine is dissolved or until the pores of the beans are opened. From there, the caffeine is extracted.

Here is a brief description of each method and how caffeine is extracted (6):

  • Solvent-based process: This method uses a combination of methylene chloride, ethyl acetate and water to create a solvent that extracts the caffeine. Neither chemical is found in coffee as they evaporate.
  • Swiss water process: This is the only organic method of decaffeinating coffee. It relies on osmosis to extract caffeine and guarantees a 99.9% decaffeinated product.
  • Carbon dioxide process: The newest method uses carbon dioxide, a compound naturally found in coffee as a gas, to remove the caffeine and leave other flavor compounds intact. While efficient, it’s also expensive.

Overall, the type of roasted coffee you buy will affect the flavor more than the decaffeination method.

However, the decaffeination process does alter the smell and taste of coffee, resulting in a milder flavor and different color (6).

Summary

Decaf coffee means that the coffee beans are at least 97% decaffeinated. There are three methods of decaffeinating the beans and all result in a milder product compared to regular coffee.

The caffeine content of your decaf coffee likely depends on where your coffee is from.

Caffeine in Average Decaf Coffee

Studies have shown that virtually all types of decaf coffee contain caffeine (7, 8).

On average, an 8-ounce (236-ml) cup of decaf coffee contains up to 7 mg of caffeine, whereas a cup of regular coffee provides 70–140 mg (8).

While even 7 mg of caffeine may seem low, it could be of concern for those who have been advised to cut their intake due to kidney disease, anxiety disorders or caffeine sensitivity.

For susceptible individuals, even small amounts of caffeine could increase agitation, anxiety, heart rate and blood pressure (9, 10, 11).

Researchers suggest that drinking 5–10 cups of decaf coffee could accumulate the amount of caffeine in 1–2 cups of regular, caffeinated coffee (8).

Thus, those avoiding caffeine should be careful.

Caffeine Content of Known Coffee Chains

One study analyzed 16-ounce (473-ml) cups of drip-brewed decaf coffee from nine US chains or local coffee houses. All but one contained 8.6–13.9 mg caffeine, with an average of 9.4 mg per 16-ounce (473-ml) cup (7).

In comparison, an average 16-ounce (473-ml) cup of regular coffee packs approximately 188 mg of caffeine (12).

The researchers also purchased Starbucks decaffeinated espresso and brewed coffee and measured their caffeine content.

The decaf espresso contained 3–15.8 mg per shot, while the decaf coffee had 12–13.4 mg of caffeine per 16-ounce (473-ml) serving.

While the caffeine content is lower than that of regular coffee, it’s still present.

Here is a comparison of popular decaf coffees and their caffeine content (13, 14, 15, 16, 17):

Decaf Coffee10–12 oz (295–354 ml)14–16 oz (414–473 ml)20–24 oz (591–709 ml)
Starbucks / Pike’s Place Roast20 mg25 mg30 mg
Dunkin’ Donuts7 mg10 mg15 mg
McDonald’s8 mg11 mg14–18 mg
Average Decaf Brewed Coffee7–8.4 mg9.8–11.2 mg14–16.8 mg
Average Decaf Instant Coffee3.1–3.8 mg4.4–5 mg6.3–7.5 mg

To be safe, look up the caffeine content in your favorite coffee shop’s decaf coffee before drinking it, especially if you consume multiple cups of decaf per day.

Summary

While decaf coffee contains much less caffeine than regular coffee, it’s not truly caffeine-free. Those looking to cut caffeine should evaluate their coffee choice first.

While many people can enjoy higher amounts of caffeine, some people need to avoid it.

Those who experience insomnia, anxiety, headaches, irritability, jitters, nausea or increased blood pressure after consuming caffeine should consider decaf if they decide to drink coffee at all (18, 19, 20, 21).

Similarly, individuals with certain medical conditions might require caffeine-restricted diets, for example if taking medications that can interact with caffeine (7).

Research suggests that even your makeup may influence how you respond to caffeine (22, 23).

Some can consume large doses of caffeine without experiencing negative side effects, but those who are sensitive should opt for decaf.

Additionally, caffeine has been identified as a possible trigger for heartburn. Therefore, people who experience heartburn or gastroesophageal reflux disease (GERD) may need to reduce their caffeine intake (24, 25).

However, it’s important to note that both conditions might be stimulated by coffee in general — decaf or not.

If you have any of these conditions, drinking a decaf dark roast, which is lower in caffeine and often less acidic, may be your best option.

Finally, women who are pregnant or breastfeeding are advised to limit their caffeine intake (26).

Summary

While many people can tolerate caffeine, those with certain medical conditions, who are pregnant or breastfeeding or who are caffeine sensitive should opt for decaf coffee over regular.

Decaf coffee is a popular alternative for those looking to cut their caffeine intake. However, it is not completely caffeine-free.

While the decaffeination process removes at least 97% of caffeine, virtually all decaf coffees still contain around 7 mg per 8-ounce (236-ml) cup.

Darker roasts and instant decaf coffees usually rank lower in caffeine and may be a suitable way of enjoying your cup of joe without the caffeine.