What’s an Aera Press
It’s a peculiar and lovely device – easily the most durable and portable option for brewing quality coffee. It produces a cup that’s thick and focused.
What’s the process?
Bring to a boil enough water for both the AeroPress and your brew vessel. 400 grams ought to do it.
Insert a paper filter into the AeroPress’s detachable plastic cap.
Weigh out 15 grams of coffee.
Grind your coffee. AeroPress calls for a fine grind – just a bit more so than drip coffee.
Assemble your AeroPress. Make sure the entire assembly is dry, since any residual moisture can compromise the device’s seal.
Place it on your scale with the flared end up, and then tare the weight. The numbers should appear upside-down. It’s possible to attach the black filter cap and place it right side-up, but this tends to cause leakage and make accurate brewing slightly more difficult.
Add your ground coffee. Be careful not to spill any grounds into the ring-shaped gutter at the top of the AeroPress, as this can make attaching the cap a challenge later on.
Add twice the volume of water to your amount of grounds. For example, if you’ve got 15 grams of coffee, add 30 grams of water. Your water ought to be about 200 F.
Gently immerse the grounds with a bamboo paddle or butter knife. The goal here is not to stir them so much as it is to guarantee even saturation. Let this sit for 30 seconds.
Add another 160 grams of water and let sit for one minute.
Use the remainder of your water (it should be about 200 grams) to wet your filter and cap. The water will serve a dual function here: It will both help the filter adhere to the cap, and it will heat your brewing vessel.
After a minute has elapsed, give your grounds 10 vigorous stirs.
Screw the cap onto the Aero Press. You’re in very close proximity to seriously hot coffee here, so please be careful.
Flip the whole assembly over with haste and control and purpose. All three. Position it atop your brew vessel and begin applying downward pressure. You ought to experience about 30 pounds of resistance here. If the pushing feels too easy, your grind is likely too coarse; if it’s very hard to push, chances are the grind is a bit too fine. Your coffee’s fully brewed once it begins to make a hissing sound. This means there’s no more water to push through the device.
Now here’s the really satisfying part, for two reasons. Once you’ve unscrewed the cap, you can pop out the filter and the puck of condensed grounds by simply pushing the Aero Press’s interior section a final inch. Then, of course, you can pour your coffee and enjoy. And please do enjoy.
The difference between the two:
The main differences between espresso and drip coffee are the fineness of the grind and the brewing time. The brewing time for espresso coffee is much shorter, made possible by coffee machines that generate up to 15 atmospheres (ATM) of pressure to force the water through the coffee.
A shot of espresso is made by forcing about 1.5 ounces of nearly boiling water through tightly packed, finely ground espresso coffee. If everything goes well, what comes out is a dark brown, slightly thick liquid with a small amount of CREMA on top.
There are many variables in the process of making a shot of espresso. The temperature of the water, the pressure of the water, the fineness of the ground coffee and how tightly the coffee is packed are just a few.Espresso coffee is a blend of several different types of coffee beans from different countries. The beans are roasted until they are dark and oily-looking.
The beans are ground very finely -- much finer than for drip coffee. The consistency is almost like powdered sugar. The more finely the coffee is ground, the slower the espresso comes out. Generally, for the best shot of espresso, it should take about 25 seconds for the water to pass through the coffee. Sometimes, the consistency of the grind is adjusted to control the brewing time.
Drip coffee is dripping boiling water over ground coffee, which is ground more coarsely than espresso coffee. The water filters through the coffee and falls into a pot. This process is slower than the espresso process, and hot water is in contact with the ground coffee for much longer. Surprisingly, a cup of drip coffee has more caffeine than a shot of espresso.
What makes a good bean?
The job is usually to pick the beans at the height of ripeness and then carefully process them so that the bean stands on its own and isn’t impacted by any rough, careless, negligent handling at the mill where it’s processed. Coffee beans have lots of parents. Some people say that a coffee gets handled by up 150 different people before it goes down the gullet. (Don’t worry – not always literally handled.) It helps to have cultivators of Coffea Arabica that produce better tasting coffee (as opposed to producing just lots of coffee). Typica and Bourbon are common older varieties (you could almost call them heirlooms) that produce good tasting coffee beans.
Some coffee beans can look lovely and yet have no taste. Some beans can look awful and taste delicious. Some ripe coffee cherries can look great – but be really light and low quality – so looks ain’t all that matters. It’s what’s inside!
It helps to grow at higher altitudes (above 3,500 to 5,500 feet) so that the bean doesn’t get too hot or grow too fast and take on more water. As higher grown beans, good beans are denser – (they grow slower) and are better able to handle the intense heat in a roaster
It helps to be picked when the beans are super ripe – big, red, and meaty – mature and fully developed. Normally they should be milled right away so that the inherent quality of the bean can stand on its own and not be influenced by the fruit or the interaction of the fruit with water and warm weather and microbial activities that can impact (usually in a negative way) the bean. Good beans will come from diligent and careful handling in the mill in order to not have the good ones compromised by the bad beans in the mill. Good segregation means the good ones get set aside.
Essentially any good bean starts out good and the trick is not to have it compromised on the way to your cup. There’s generally very little anyone can do to improve the quality of a coffee bean – but there are lots of ways to deleteriously affect the quality of the coffee. Imagine a long slow battle hammering away at beans – the barbarians of carelessness, inattention, thoughtlessness and inexperience.
Other things that help:
- For the farmer to have vision, hope, knowledge and a steady buyer with clear expectations and a ready check book.
- A roaster that is willing to pay attention to the potential a coffee has and not just cook and bake it or roast the heck out of it.
- You the customer – taking care to use a nice brewer, clean water, cleaning it regularly, serving and enjoying it fresh.
What makes a Good crema
There are several elements to "extracting" espresso coffee and achieving rich, creamy crema.
Some beans will never produce crema, even some that are sold as espresso roast. The best espresso roasts use primarily Arabica beans, which originated in Ethiopia, but have spread, throughout the coffee-growing world. Some Robusta beans are typically included in the blend because of their ability to generate crema. Most people imagine espresso roast beans to be dark, but it all depends on the roast.
It seems everything has to be just so when making espresso and producing good crema. The next thing is the grind. Basically you are aiming at not allowing the water to pass through too quickly, but not making the grind so fine that your machine won't be able to force the water through without straining. This is achieved in two ways: the fineness of the grind of the beans, and the tamping of the beans in the portafilter. To achieve good crema, for a double shot, extract 2 to 2.5 ounces of coffee into your cup in 20 to 30 seconds from the moment you turn on the pump. You will see this referred to in various places as "The Golden Rule". (I have a completely different Golden Rule for perfect espresso you should read about.) A single shot should still take 20 to 30 seconds, but now you will want 1 to 1.5 ounces of coffee in your cup.
Tamping is the process of pressing down on the ground coffee in the portafilter with a tool known as a tamper. The tamper should fit snuggly into the filter basket. Tamp with even pressure of about 30lbs. How do you know what 30lbs is? Get out your scales and put them on the counter and practice so that you get the feel for how hard you need to press down. Tamping is aimed at achieving an even and consistent flow of the water through the coffee. If the coffee is packed unevenly, the water will find its way through gaps in the coffee, flowing too quickly through them for there to be a good extraction; most of the water will flow through the more loosely packed coffee, and not flowing through some of the coffee in the filter basket at all. In fact it is possible to bang out the coffee after the extraction is finished and see whole areas of coffee that are completely dry. You can't make good crema without tamping your coffee before the extraction.
Correct brewing temperature.
The temperature of the water has to be hot enough to caramelize the sugars in the coffee to make the crema. The optimal temperature range is around 92 to 96 degrees Celsius (198 - 205 Fahrenheit). The best machines use a metal for the boiler that has good heat retention, such as brass. Also, many machines offer separate boilers for coffee brewing and steam generation. This is because the water used for steaming has to be heated to a higher temperature than is the optimal temperature range for brewing the coffee.
Correct brewing pressure
Effective brewing requires pressure of at least 130 psi, which some domestic machines just don't seem capable of. The pressure rating for your machine will be quoted in "bars". Many of the cheaper domestic machines achieve 8 bars of pressure, which is a stretch when it comes to achieving good crema. Get a machine that is rated about twice that. Sometimes these machines are described as "semi-commercial", but don't you believe it; consider this the minimum standard for your home espresso machine.
At the beginning, you will have to accept a certain amount of trial and error. Practice, practice, and practice some more. Vary everything: the grind, the amount of tamping pressure you use, and your beans.
With just a little bit of practice, provided you are using good fresh beans, you too will be pulling the perfect espresso shot with a rich layer of crema!