Making french press coffee is an artform that few can master. The most important aspect of making the perfect french press coffee is knowing how long you need to steep your coffee beans before pushing the plunger down.
Steep a coarse ground of coffee for 6 to 8 minutes. 4 minutes is enough for a medium ground. This is all the time needed for coffee beans to release their ‘caffeine part’ into the water. Once this extraction period is over, you can push the plunger down and continue with the next step.
The rest of this article will explain why this time period is enough and the factors affecting how long you should be steeping coffee in a french press. We’ll also give you a brief overview of the remaining steps in a french press coffee brewing process. So keep reading.
Why you should steep coarse coffee grounds for 6-8 minutes
Any particular coffee bean will always have a fixed amount of caffeine in it. However, you can make countless different types of coffee from it, each will taste different.
This is because your choice in brewing method impacts how much of that caffeine and consequently, flavor is extracted.
Why principles of equilibrium matter
You can only make great french press coffee once you understand how the caffeine extraction process works.
Any given system is in equilibrium once the rate of a forward reaction is equal to the rate of backward reaction.
The system in this situation is the french press, the forward reaction is caffeine extraction into the surrounding water while the backward reaction is the caffeine going back into the coffee grounds.
When you’re extracting caffeine from coffee beans, you’re doing so based on a very simple principle of diffusion. Since the caffeine content is higher in the beans than it is in the water, it moves into the water.
It goes from an area of higher concentration to lower concentration.
However, since a french press doesn’t replace the water surrounding coffee beans, you can only extract so much caffeine. At some point the caffeine content in the water will equate the caffeine content in the coffee beans.
Once that happens, equilibrium is established. Going any further is not possible.
Reaching this point means you can’t extract more caffeine or flavor from your coffee beans.
The exact time it takes to reach this point depends on how fast extraction is happening. That depends on 3 main factors explained later in the article.
Recommended steeping time
As a rule of thumb, when you’re working with coarse coffee grounds, you can get optimum extraction within 6 to 8 minutes. With medium-coarse coffee grounds, the time period is reduced to 4 to 5 minutes.
Factors affecting coffee extraction time
1. Coarse coffee grounds require a longer extraction time
The way you grind coffee will affect extraction time. A very coarse grind requires a longer steep than a fine grind.
Coarse ground coffee dissolves into water slower than fine granules. The explanation behind this difference in rate of dissolution is that the super fine grind size increases the surface area to volume ratio of coffee beans with water.
So at any given point in time, the solvent (water) has access to a lot more of the solute (coffee) than it would have had if there were few large grains instead of several small ones.
2. Hot water will lead to quicker extraction
Hot water has fast moving particles which collide with coffee grounds faster than slow moving particles. This leads to more effective collisions and reduces the necessary extraction time.
So the warmer your water is, the less time you need to steep coffee grounds.
Avoid using boiling water as that can damage your coffee beans and lead to a bitter and yet bland cup of coffee.
3. The stronger you want your coffee, the longer you extract
A logical extension of the first factor is that the longer you steep your coffee, the stronger it will be since you will have extracted more flavor from it. Since coarse beans have an extraction period of 6 to 8 minutes, you should steep for 6 if you’re looking for a mild flavor and 8 if you want a bold flavor.
Bear in mind that the recommended time periods ensure that you get a flavorful cup of coffee either way. So rest assured, you will get a decent tasting drink. However, you have power over how strong that flavor is to a certain degree.
Note: Do not leave your coffee grounds to steep more than the maximum recommended time period. It will not enhance your drink’s flavor and will instead only make it bitter.
The coffee brewing process – a brief french press overview
Grind your coffee beans to a medium-coarse texture and add them to your french press.
Then add water but don’t put the lid on just yet. Let the two components sit for a little while.
Give your coffee and water a gentle but thorough stir after 30 to 45 seconds or once the bubbling stops. Then put the lid on and shoot for a target brew time between 6 and 8 minutes. Then plunge gently.
Take the lid off and pour out your brewed coffee. Leaving it in the french press will lead to over extraction which can cause your drink to taste bitter.
Can you over steep french press coffee?
Yes, you can over steep french press coffee. Your drink will taste bitter and quite rough if you do so. For coarse coffee grounds, this can happen as early as the 10 minute marker. Coffee beans that have been grinded to a medium to medium-fine consistency can go bitter at the 7 minute marker.
How do you know when french press coffee is done?
There are no visible signs that your coffee is done brewing. Keep an eye on the time and make sure you aren’t over steeping according to the guidelines given in the article above.