On Espresso – Part I
Ah, coffee. What a great friend it has been. It’s been there countless times to wish me a good morning, to keep me company on a long road trip, or to stay up with me late at night studying. It’s seen me at my best and my worst. All I do for coffee is spray it with scalding water and throw it away when I’ve had enough. (Between you and me, I don’t know what it’s getting out of this relationship.) But, it’s always been there at my side when I need it most.
Lately some of us here at MindTribe have had a fascination with coffee, specifically with espresso. We not only enjoy drinking it, but making it is always a fun little experiment too. Like so much that we do here, making espresso is very much both an art and a science.
To make your typical pot of drip coffee requires nothing more than some hot water, ground beans, and a filter. Mix them together and you have coffee! That’s it—so easy a caveman could do it! I love a good cup of drip coffee, but I find it technically boring (though Bluebottle might disagree).
Espresso is not so simple. After all, espresso is only possible with “recent” advances in technology, and it is pretty new relative to coffee. To make it properly, you need water at just the right temperature. You need the water at a specific pressure. You need a precisely ground 14 grams of espresso beans. You need 30 lbs of even pressure applied to the grounds. And you need to extract 2 ounces after 25 seconds or you did it all wrong. Blah, blah, blah, blah. All this sounds like a lot of work to most people. To us it sounds like fun.
If there was an IEEE standard for espresso extraction, it would include the rules below. These are inputs to a process, ingredients to a recipe. A proper espresso machine should be capable of reaching these levels closely and should do so consistently.
- Water at 200°F, or 93°C – This refers to the water that is being pushed through the coffee grounds
- About 9 bar of water pressure – This refers to the pressure of the water right at the top of the espresso ground “puck” just before it touches any coffee
- Correct coffee grind – The fineness of the grind must be adjusted until it is just right. This combined with tamping pressure and coffee ground quantity will determine how fast the espresso comes out.
- 14 grams of coffee grounds – This is the agreed-upon standard for two shots of espresso (Most machines do two shots at once. Use 7 grams for one shot machines.)
- 30 lbs of tamping pressure – After adding 14 grams of ground coffee, a tamper should be used to apply 30 lbs of even pressure to the top of the grounds
Now, even if a machine is capable of meeting such specifications, it is up to the person making the espresso to make sure it actually does so. On home machines, it is rare to have any instruments with which to monitor water temperature or pressure. Most of the time, the only metrics you get are from the end result: the espresso itself. This makes it somewhat of a guessing game until your brain starts learning correlations between what you put in and what you get out. The following is what most people will use to gauge how well they did:
- 1 ounce of espresso per shot for a 25-30 second extraction time
- Pours out like warm honey
- A top layer that is dark brown, not blonde, with a slight tint of red
- And, it should taste, um, good
If you would like to begin experimenting with espresso yourself but do not have a machine, here are some recommendations in different price ranges. However, be sure to save some money for a grinder (that is a topic for another post).
DeLonghi EC155 – $95 at Amazon
People say that for the price, there is nothing better out there.
$200 – $1000:
Rancilio Silvia – $594 at Whole Latte Love
Silvia is picky about some things (the grind has to be just right for example) but can make a fantastic shot if she gets what she wants. It can make a great hobbyist machine too since there are many people out there upgrading and modifying these machines.
$1000 – $3000:
Expobar Brewtus III-R with Rotary Pump – $1899 at Whole Latte Love
Wowee, what an awesome machine. PID control loops, rotary pumps, and E61 brew groups, oh my! If you have money to burn, send one of these to yourself. If you have more money to burn, send one to us.
We use a Rancilio Silvia. This model line has been around for a while and has stood the test of time. It’s not perfect, but we love it just the same.
Nice big brass boiler. Brass has a lot of thermal mass, which helps to keep the temperature steady.
58mm commercial-grade portafilter.
Three-way solenoid valve.
Generally competent. It is capable of meeting the required inputs for brewing espresso correctly. Many of the cheaper machines simply can’t meet the espresso specs no matter what you do.
Built like a tank.
Only one boiler, so after you pull a shot you have to wait for it to rise up to steaming temperature.
Temperature can fluctuate despite the big boiler. This is because it is regulated by a thermostat.
It’s picky about the grind. If it’s not just right, you likely won’t get a good shot.
Small water reservoir and drip tray.
Finally, to really feel like you fit into the cool coffee club, try to use these terms more throughout your day:
- Espresso – A drink made from the high-pressure oil extraction of coffee beans. Increased pressures are used in order to make a higher concentration and to extract different flavors than what is possible using conventional drip coffee machines. Espresso can be served itself or be used to make other drinks such as lattes or cappuccinos.
- Crema – A syrupy but foamy layer of emulsified coffee oils that tops a shot of espresso.
- Barista – This is the person making espresso either at a coffee shop or you with your own machine. Means bartender in Italian.
- Portafilter – The handle thing on espresso machines.
- Basket – The perforated cup that snaps into the portafilter. This is what filters the coffee and keeps the grounds out of your drink.
- Pull a shot – To make a shot of espresso. The word “pull” comes from the days when the machines had levers to build the pressure rather than electric pumps.
- Tamper – A tool used to compact the grounds. The compact grounds provide the resistance needed to build the pressure to extract the oils from the coffee grounds.
- Expresso – A word a barista uses before they make you a bad cup of coffee.
Espresso is something that can be causally enjoyed, something that can become a real hobby, and for some a true obsession. For us at MindTribe, I’d say we’re somewhere in the middle.