Most people use spoons and scoops to measure ground coffee when brewing their Joe. This is especially true for people who buy preground coffee.
But how much caffeine is in a tablespoon of ground coffee?
On average, there is about 60mg and 110mg of caffeine in a level tablespoon of ground Arabica coffee and Robusta coffee respectively. A heaped tablespoon may have up to three times the caffeine in a level tablespoon. Caffeine accounts for 1.2% and 2.2% of the weight in Arabica and Robusta coffee respectively.
Why Your Coffee is Likely to Have More Caffeine per Tablespoon than the Average Amount
Here are four scenarios where a tablespoon of coffee is likely to have more caffeine than the average amount in Arabica coffee.
- Chocolate-covered coffee beans. A tablespoon of chocolate-covered coffee has more than three times the caffeine in Arabica coffee.
- Instant coffee. The USDA states that a rounded teaspoon of instant coffee that weighs about 1.8 grams contains 57 milligrams of caffeine. Fortunately, you use only a small amount of instant coffee per cup.
- A heaped tablespoon of coffee can measure as much as 15 grams as compared to the average 5 grams per level tablespoon of ground coffee. Consequently, the caffeine content in a heaped tablespoon of ground coffee is nearly triple the average amount in a level tablespoon of coffee.
- Blends of Arabica and Robusta will have significantly more caffeine per tablespoon than Arabica coffee especially for the blends with higher proportions of Robusta.
Keep in mind that about 70-90% of the caffeine in unbrewed ground coffee will be extracted during brewing.
Would you like to find out the amount of caffeine in a single bean of coffee?
Caffeine in Instant Coffee vs Regular Coffee
On average, instant coffee contains more caffeine per gram (32mg per gram) as compared to about 10-12mg of caffeine per gram of regular coffee.
However, you use 4-6 times more regular coffee grounds than instant coffee granules to make a cup of coffee which makes a cup of regular coffee to be much richer in caffeine than a similar cup of instant coffee.
For example, a 6oz cup uses 1.8 grams of instant coffee granules whereas the same 6oz cup requires 9-11 grams of regular coffee.
Assuming a 100 percent extraction of caffeine, which is highly unlikely, a 6oz cup of instant coffee would end up with about 57 milligrams of caffeine as compared to about 70-135 milligrams of caffeine in a similar cup of regular coffee.
Read this separate topic about the typical size of a cup of coffee that you might find very interesting.
How To Use the Information about the Caffeine Content in a Tablespoon of Coffee
Without an actual measure, there is no telling how much caffeine per tablespoon is contained in the coffee beans that you have in your house. However, the average of 60mg of caffeine per tablespoon of Arabica coffee is a great guide to knowing how much caffeine you are likely to have in your cup after brewing.
Since about 75-90% of the caffeine in dry coffee grounds is extracted, you are likely to end up with 45-54mg of caffeine in your cup for every tablespoon of coffee.
Assuming 100 percent extraction of caffeine (60mg per tablespoon), you should not brew more than 6.5 tablespoons of ground coffee in a day to stay below the FDA ceiling of 400mg of caffeine per day for healthy individuals. The margins are lower for the more caffeinated blends of Arabica and Robusta that have higher quantities of Robusta.
For instant coffee, consuming more than seven teaspoons is likely to cause diuretic problems.
A tablespoon of Arabica coffee grounds has about 60mg of caffeine whereas an equal spoon of Robusta coffee has 110mg of caffeine. A 1.8mg teaspoon of instant coffee has 57mg of caffeine.
Although instant coffee has more caffeine per gram of dry coffee than regular coffee, a cup of instant coffee has far less caffeine than an equal cup of regular coffee because most people use about a teaspoon of instant coffee per cup.
Knowing the amount of caffeine in a tablespoon of coffee can aid you to approximate the quantity of ground coffee to brew in a day to avoid caffeine’s undesirable effects such as diuretic issues.
How Many Tablespoons of Coffee Should You Use per Cup?
As a general rule, 1 gram of coffee grounds uses 15-18 grams/milliliters of water. Assuming an 8oz (237ml) cup of coffee, you need 2½ to 3 tablespoons (13-15 grams) of ground coffee. Using fewer tablespoons of coffee yields a weaker brew and vice versa.
Always check the size of the cup that you want to fill with coffee to figure out the amounts of coffee grounds to use. Use a measuring cup to measure the quantity of water when you don’t have a scale; a water bottle that has measurements is perfect.
Are Two Tablespoons of Coffee Too Much?
Two tablespoons of coffee are enough to brew 6-7 ounces of coffee. A single spoon holds about 5 grams of ground coffee so you might want to add more grounds when brewing a larger mug of coffee.