One of the main qualities of espresso is the creamy foam called crema which is produced when espresso is brewed.
The Aeropress is commonly praised as the best press coffee and espresso maker. We did an article on creating espresso with the Aeropress and the biggest difference between an espresso maker and the Aeropress is that the Aeropress doesn’t normally create crema. We have to emphasize that the method outlined here is for people who are willing to go the extra mile to get exactly the coffee they want. For most people going the automated route such as using an automatic coffee maker with grinder will provide more consistent results.
How is Espresso Crema Created?
Crema is created when several requirements are met. Below are all the things needed to create crema.
- Coffee Beans – Not all coffee is created equal, and not all coffee beans produce crema. Even espresso specific roasts can sometimes not create crema. If you buy beans from a reputable source then read around or ask the brand if the beans are known to make crema, or try the beans yourself. You can also use ready made Ground Coffee, although beans are recommended for best results.
- Coffee Grinder – Generally an espresso roast needs to be ground finer. The finer grind prevents water from passing through the coffee too quickly. This is important when we talk about the next requirement – pressure.
- Brewing Pressure – The brewing pressure needed to create crema is roughly 130psi. This pressure measurement may also be rated in bars. Generally speaking you need about 9 bars of pressure to create crema.
- Brewing Temperature – In order to caramelize the sugars in the coffee needed to create the crema, a water temperature of 198-205 degrees F (92 to 96 degrees Celsius) is needed.
- Tamping – When you tamp a coffee shot you need to apply roughly 30lbs of pressure to the ground coffee to create a ‘puck’. Correct tamping ensures a proper flow of water through the coffee grounds.
Can the Aeropress Produce Crema?
The short answer is YES! The Aeropress can create crema when the correct techniques are used. The above requirements can be met through various techniques.
How to Make Crema with the Aeropress
Use our tips on meeting the needed criteria to have your Aeropress creating crema.
- Choose the Right Coffee Beans – If you are missing any of the other parts of the process you won’t know if your coffee beans are capable of creating crema. We suggest trying the roast through an espresso machine to see if it creates crema before using the roast in the Aeropress. If you don’t have access to an espresso maker then try searching online for roasts that are reputable for creating good crema.
- Grind Your Roast – Follow the same procedure you would to grind up an espresso roast. Use a fine grind to keep the water from passing through the roast too quickly. Generally the fresher the roast and the fresher the grind, the more likely to produce crema.
- Heating Water to the Correct Temperature – Heat water to the ideal temperature range of 198-205 degrees F (92 to 96 degrees Celsius). Try a temperature controlled electric kettle for quick and easy water heating.
- Filter and Add Coffee to Your Aeropress – You need to have the correct filtering and coffee amount used in order to be able to apply high pressure to your coffee without the water passing through too quickly. Try using a filter that allows less water to pass through like a Metal Filter or multiple Paper Filters. Then add your coffee to the Aeropress. It is better to use more coffee here since the more coffee you use, the slower the water will pass through.
- Brewing Pressure – This is where things get tricky – if you set your filter and coffee amount up correctly, you should be able to put a considerable amount of pressure on your Aeropress. Hopefully this will be enough to create crema, but research shows its probably not humanly possible to get enough pressure going without some sort of mechanism. This means you will have to get creative to create the needed 130psi/9 bars of pressure. Check out this YouTube video for an example: http://www.youtube.com/watch?v=GIfZ84qtBOc
We hope that you find success brewing creama with the Aeropress. If you have any suggestions or techniques, please leave them in the comments below.
If you really need that much pressure then this is not going to work.
A few basic calculations:
Diameter of Aeropress filter is 6.4 cm
The area of the aeropress filter is (6.4cm/2)^2 * pi = 10.0530965 cm^2
Pressure required is 130psi according to this article
According to google 130psi to newtons/cm^2 => 89.6318448 newtons / (cm^2)
Multiply pressure by the area = gives us 901.077585 newtons
Again according to Google 901.077585 newtons to pounds => 202.5703 pounds force
That means that if you weighed 202.5 pounds you would have to literally put your entire weight onto the aeropress. Even if the press didn’t break, I somehow doubt that you would be able to do this.
If you weigh less than 202 pounds you’re out of luck.
Anyone have any other ideas on how to fix this problem.
Phineas – Engineering Student @Columbia SEAS
There is a misunderstanding…the tamping (person squishing grounds into puck) needs only 35# of compression. The 9 bars of pressure (around 125psi) is measurement of the pressure steam builds up as it pushes itself they that puck.
*as it pushes itself thru that puck. (blasted autocorrect)
Phineas – you forgot the pi for the area, which means your calculations should end up at 3.14 * 202 pounds, about 282,5 kg.
If your calculations are onto something, a metal aeropress with a swivel to apply pressure, might pull this off, but the plastic probably has no chance.
If the above assumptions are correct, I have no idea. Another blog claimed 120 psi, and showed a picture of espresso with crema from aeropress, using a wooden installation. I doubt this installation applied 300 kg of pressure to the aeropress.
This entire article and these comments are a completely incorrect approach to improving the Aeropress. First: Lexan is extremely tough and can easily handle the necessary pressures. Whatever the math works out to be, it wouldn’t be hard to achieve the proper force with some sort of lever set up, as mentioned in the article. Second: 130 psi is what is needed to mimic espresso. The point is to modify the process to achieve pressures closer to 130 psi. However, I agree that stainless steel is a more desirable material for high-temperature food preparation.
As for the article, stop trying to make the Aeropress into something it isn’t. I like crema too, but there are other ways to get it than espresso. These must be explored with the Aeropress because the Aeropress, by design, eliminates the main reason why espresso crema even occurs: the crema is filtered and ejected first, not last (you can watch this occur in a Moka Pot). Because of the Aeropress design, the crust (where the crema resides) is filtered last. The puck re-absorbs almost all of the crema at the end. The best way to save the crema would be to press it while it is still inverted. The Aeropress’s cap has a non-smooth outer circumference, making this very tricky.
Finally, I don’t know what this article is talking about as far as how rare crema is. Every coffee I’ve had can make crema if LOWER temperatures are used. This is apparent with Turkish coffee. If done properly, it is the creamiest coffee of all and never gets hotter than 165F. Everyday, I use a french press with water at 165F and consistently get a nice froth in my cup.
In conclusion, treat the Aeropress as something between an ibrik and a Moka Pot. Use lower temperature water and press it while inverted. This will produce awesome crema.
There is no way you can create the crema shown in the picture above. Shame on WeCraveCoffee for misleading coffee drinkers in this way.
The aeropress does not produce a crema.
Sorry but you are wrong, wrong, wrong. Did I mention you are wrong? I make crema with my Aeropress Every-Single-Day.
Also .. did I mention that you were wrong? Because You were Wrong.
See Tim’s comment above.
The trick is to use a metal filter and press it whilst inverted till you get the crema forming on top of the Aeropress, then pour this over into your cup before finishing the press whilst upright.
I’m not sure the calculations are that simple. Can the area of the filter simply be taken as the surface area?
I would have thought that the area which is determining the pressure would be the allowable area which is passing the coffee water through – i.e. the total area of the small holes in the filter, not the entire filter area. An example would be if there were 10 small pin holes (in a metal filter plate) of area 1mm squared each, your effective area should be 10mm squared.
This is of course simplified, as a paper coffee filter is made of fibres and on a micro-scale has a 3D volume carrying out the filtration, not just a single 2D layer with holes in it.
Not sure exactly how you would calculate it but it might work out that the stated PSI readings are not outrageous after all.
A couple of thoughts.
1) Rather than tool out the details, here’s the simple engineering approach: If you base the pressure on the filter paper area, then: filter paper area is about 4 square inches. (radius a bit more than 1 inch) Desired pressure is 130 psi. 130×4=520 pounds.
2) [HINT] Why are you using the area of the filter paper? 😉
You should really be using the area of the nozzle port, not the filter paper.
Actual answer will be much smaller than 520 lbs.
Oops, my bad. I didn’t know what an Aeropress looked like. There is no “nozzle” I now see.
Still, you should be using the combined area of all the little holes, which is much less than the area of the filter. It’s maybe 1/3 to 1/2 the area of the filter. So, we’re back to 175 – 250 lbs or so required.
The 130psi figure is probably derived from the often quoted figure of 9 bars required to brew an espresso.
What a roundabout way of calculating, if you’re going to express the result in pounds.
10.0530965 cm^2=1.55823307 square inch
1.55823307*130 PSI (=pounds per square inch)
=202.5702991 pounds.
expresso isnt about crema in the first place its about ratio 1:2 coffee to water is what determines a shot a good expresso isnt baed on the crema but the concentration of the coffee to get the 1:2 ratio you need 9 bars at 200 degrees passed through in roughly 20 sec thats what defines an expresso
so lower the temp lower the pressure and augment the time
and figure out how to get a 1:2 ratio with the aeropress with out changing hardware if you half it its roughly 100 degrees at 60 psi for 40 sec pass through aeropress can probably handle that
This method will yield a totally different extraction. There are so many compounds in coffee beans, and we only want the ones we want (lol sorry about ambiguity, but further details always fall away from me in this). The extraction methods we use are results of how many years? Have we discovered them all? Shirley not!
I’m not nearly so precise – I use a basic electric kettle, fill with 4 cups and heat for 2 minutes, which gets me to around 185F. I create a a fine grind using a Cuisinart and try to use fun beans like those from Peru or Ethiopia. I don’t stir the coffee when I add the water, and I think this is key. I also don’t use the inverted method, which stirs the coffee when you flip it. I let it sit for 20-120 seconds depending on how distracted I get. And then I press my coffee. With my current bag of beans, I’ve been getting pretty decent crema, but stuff like Eight O’clock (my cheap backup) generally won’t do the trick.
You guys calculating numbers are forgetting a couple of things.
1. We’re not dealing with hydrologic fluid with little compression here, you’re forgetting to calculate the pressure absorbed by the large volume of air above the puck.
2. Pressure drops with flow, so you’re assuming there is no flow when you calculate force over the area.
The tricky thing with espresso is to keep a consistent 9bar and temp over the full 25 – 30 seconds of extraction. I just got an aeropress and it makes a great plunger style coffee. I’ve just tried a high pressure method with my full body weight and it needs a bit of tweaking to be called good!
A tip, if you don’t have a metal filter and want the water to pass through slower, is to add powdered cinnamon. I personally like the taste of cinnamon in my coffee, and the powder keeps the water from passing through quickly since it is so fine.
Just tried this for the first time and it actually worked. Thanks.
I love it. Absolutely my favorite coffee maker for lattes! Love the automatic shut-off when selected water amount is reached.
The only way I can get a nice thick crema is to:
– grind 3 aeropress scoops of espresso or Starbuck’s Dark French Roast coffee beans (fine)
– rinse/wet a paper filter and then assemble the chamber
– Boil water to 180 degrees with the GatorCoffee Pour Over Kettle
– Lightly wet the grounds and wait 30 seconds (no water should pass through at this point)
– Fill the upright chamber to the 2.5 mark
– Stir 10x
– Slowly press and savor the thick, caramel colored foam oozing out
I tried making crema with Able’s fine and JavaPresse metal filters and just couldn’t do it. I tried using hotter water as well.
Any suggestions?
not sure of diameter. Guessing here, if it is 2.25″ then you will need 918 pounds to achieve the 9 bar. I Like my aeropress but it ain’t espresso.
This article is misleading at best. The question was “can the Areopress create creama?” You indicated the answer was yes, but offer no methods other than watching some one else’s youtube video.
Garbage article.
I can get crema like in the pic, but its hit or miss….I find it to be more dependent on the beans, and water chemistry…Aeropress is best brewer I have found.
The surface area of the plunger is what you would use. It is what you are applying pressure to. Your weight is distributed to the fluid over that area only.
You can create plenty of crema with the AeroPress using the JOEPRESSO attachment.