Having watched countless baristas pull shots in your coffee-drinking lifetime, you would think it wouldn't be that hard to do at home, right? So, why does your home-brewed espresso come out watery, with no evidence of a crema one day, and thick and bitter the next? It can't just be that owning an expensive La Marzocco model is truly the barrier for entry when it comes to pulling a top-notch shot.
Nothing can beat the consistency of pulling shots all day long on a professional machine to perfect your espresso game, sure, but if you're merely dabbling in a daily Americano with a model that's appropriate for your kitchen size or budget, there are still ways to dial in your espresso procedure for the best possible outcome.
Read more: I Tried a $140 Espresso Machine That Pulls Creamy Shots and Is Slimmer Than a Blender
Kaleena Teoh, co-founder and director of education for Coffee Project New York, talks us through all of the steps of pulling shots, so you can brew espresso at home like a professional.
Espresso basics
Espresso is a precise brewing method, not a drink. Pamela Vachon/CNET
"The word 'espresso' itself is not just a drink, it's actually a brewing method that involves pushing hot water through a compacted puck of coffee," Teoh explains, which can be accomplished through a machine with a boiler, or manually, as in a stovetop espresso pot. It necessitates a particular calibration of pressure and temperature, but a high-end machine isn't actually required.
"The two most important things are the machine's ability to maintain pressure and temperature as you're pulling the shot," she says. In most models for home use, you may not be able to make any adjustments, but gauges or displays that indicate pressure and temperature can be reassuring. Also, make sure that you're closely following the process outlined by the manufacturer, which may involve a step to preheat the water before brewing. Ensuring that your espresso machine is clean, by regularly brushing grounds from the portafilter loading point, and periodically flushing with hot water, is also important for quality control.
More so than the coffee machine itself, Teoh recommends another crucial piece of equipment for the best home-brewed espresso. "If you have a basic machine that can maintain pressure and temperature, that's good enough, but if I have extra budget, I would put it on my grinder," Teoh says. "Having a good grinder, especially a good burr grinder, is very, very important for espresso."
Espresso grounds: Grind size matters
Finely ground coffee beans is key for proper espresso. Pamel Vachon/CNET
Because espresso is a process, not a drink, there's really no such thing as espresso beans, and you can choose a provenance and a roast that suits you for espresso, even a light one. It's the grind of any beans you choose that has a big impact on the outcome of the shot you pull.
"The grind size should be around the range of fine sand," says Teoh, which is smaller than that which is used for drip coffee, french press or pour-over, but not as fine as the powder that would be used for unfiltered brews such as Turkish coffee. This element makes it all the more important to have a grinder that allows you to fine-tune the grind size with a dial, rather than just a few predetermined settings, which may not provide the nuance you need.
Teoh also naturally recommends the freshest coffee beans for the best espresso. Grinding to order is great, but you're also looking for beans that have been as recently roasted as possible, ideally within a matter of weeks.
Espresso has its own golden ratio
Just like drop coffee, espresso has its own golden ratio. Pamela Vachon/CNET
The "golden ratio" is different for espresso than it is for drip coffee, fresh press, or pour-over, since you generally don't have much control over the amount of water that goes into the brew. Instead, you're looking for a specific ratio between the amount of grounds and the amount of liquid coffee that comes out at the end, and yes, professional baristas are weighing finished espresso to ensure quality.
"The coffee to water ratio is between 1 to 1.5 and 1 to 2.5, meaning that, for every one gram of ground coffee we put in there, we want to yield between one-and-a-half to two-and-a-half grams of liquid espresso in the cup," Teoh says. "That ratio usually gives you a pretty good, what we call 'strength.' It wouldn't be too intense. It also wouldn't be too watery." For the sake of easy calculations while you're experimenting with these ratios, 1:2 is an average range to aim for. The smaller the ratio between grounds and liquid espresso, the stronger the coffee.
Despite what marketing language would have you believe, there's no difference between coffee and espresso beans. Basak Gurbuz Derman/Getty
If your espresso machine has controls that allow you to adjust the strength of your coffee, you can experiment with those. If not, other factors that you can control, which can affect the outcome in terms of the ideal ratio, are the grind size, as above and also the consistency and pressure of the puck.
Preparing the puck
Use your finger to gently level the grinds. Pamel Vachon/CNET
After measuring your grounds into the portafilter, according to both its size and the manufacturer's recommended measurement for a single or double shot, the next step is to level it before tamping. "Use your fingers to make sure that it is distributed evenly before you tamp down," Teoh suggests, so that you don't end up with an uneven puck. She explains that water will always look for the path of least resistance between the tank and your cup, so if there's an area in the portafilter that contains a smaller or less pressurized volume of grounds because it was uneven to begin with, that's where the water is going to primarily go, resulting in an improper extraction.
A heavy, high-quality tamp should be applied, which is the correct size for your portafilter. Portafilters come in various sizes, typically 51 or 54 millimeters in diameter for home espresso machines. If your machine didn't include a tamper or came with a lightweight, plastic one, you'll want to upgrade it.
Your puck should be level and smooth before pulling a shot. Pamela Vachon/CNET
Tamping the puck doesn't involve applying extreme force, but "you will want to push down to a point where you feel like it's pushing back," Teoh says. "You're not using your whole body weight on it, but it's also not like you're stamping a card. You want to push down and create a dense puck that is tightly packed."
If you want to be precise about pressure, some guidance suggests applying between 20 and 30 pounds. Teoh also notes that spring-loaded tampers are available, making it easier and more consistent to apply adequate pressure.
What about the crema?
Crema is less about flavor and more about mouthfeel. Pamela Vachon/CNET
The crema, or foam layer on top of your shot, may be desirable, but it isn't necessarily an indicator of a properly pulled shot, nor does it significantly affect the flavor.
Teoh explains that carbon dioxide is trapped in the coffee beans during roasting, which is released during brewing and creates the foamy crema. However, it isn't the density of the puck that determines whether it appears during brewing. "Your crema is not just CO2, but it's also oils and insoluble matter in coffee," Teoh says.. "There are a lot of aromatic compounds in there, but the actual flavor of your coffee lies in the darker liquid at the bottom. The crema doesn't really carry a lot of flavor, per se, but it does help with mouthfeel."
The absence of crema may have less to do with the mechanics of the shot and more to do with the roast itself. "The freshness of the coffee makes a difference," Teoh says, "and some coffee, if it's roasted really lightly, will also not have a lot of crema." To maximize your crema potential, then, you're looking more for beans of a darker roast that have been recently roasted.
Taste and adjust
The golden ratio is a good place to start, but don't be afraid to adjust if the flavor doesn't suit your taste. Pamela Vachon/CNET
It's your espresso, so it's your palate that matters most for the final outcome. Small variations in the freshness and roast of the coffee, grind size, measurement of the grounds, tamping pressure and consistency, and temperature -- to the degree that you can control it -- will all affect different outcomes. For a balanced brew with a nice mouthfeel and length to its flavor, continue to experiment with the above adjustments until it suits you.
"You might not be experienced making espresso, but you are experienced as a consumer," Teoh says, "so you know what you should be tasting in your cup, and if it's not right for you, then you know that something needs adjustment." Given all of the possible variables above, hopefully it's just a matter of tweaking small things, rather than needing a whole new system.