My evaluation process for a home espresso maker is similar to how I test standard drip coffee makers. First, I hand wash and dry all removable parts and accessories. For most espresso makers, that’s the filter basket, metal portafilter inserts, water tank, and so on. Then, I run one brew cycle using only hot water to rinse away any residue from production.
Most automatic espresso machines, except for the luxury fully automatic models, do not have an integrated coffee grinder and I prefer to test espresso machines with freshly ground coffee, not pre-ground coffee, so I provide my own grinder: the Breville Smart Grinder Pro. I chose this conical burr grinder for two reasons. First, it is calibrated more for espresso than for drip or other brewing methods. That means it produces a fairly fine grind. Second, the grind size is consistently uniform. Both of these factors are crucial for good espresso brewing.
To pull shots, I start with the suggested method provided in the product manual for a particular machine. This usually includes the amount of coffee grounds expected per shot, along with any guidelines regarding coarseness level. Likewise, I follow the tamping instructions (light, medium, or hard tamping) if the manual includes them.
Whenever possible, I double-dip espresso shots for all of my test runs. I make sure to record the weight of the coffee grounds I use, plus the weight of the espresso for each shot I pull. This data, along with measurements from a handheld refractometer, allows me to calculate two important percentages: total dissolved solids and extraction rate.
As with any coffee brew, the ideal extraction percentage for espresso is between 18% and 22%. This will produce a well-balanced cup, assuming you are extracting coffee components from your grounds evenly and efficiently (both flavor and caffeine).
There aren’t many home espresso machines that can make quality shots. This one comes from the Breville Barista Express.
If you over-extract, you run the risk of off-flavors (bitterness) leaching out after the good stuff. On the other end of the scale, under-extracted brews often have undeveloped flavors. Lacking sugars and other caramelized organic chemicals, these shots taste sour, bland, and watery.
Unlike a cup of drip coffee, barista-quality espresso needs to be concentrated. While excellent drip coffee typically has a TDS percentage of 1.3% or 1.4%, great espresso has a much higher percentage. The Breville Barista Express, for example, produced shots with TDS percentages as high as 12.4%.
The shots I pulled were balanced, with an extraction of 18.6%. The test beans I used were the same variety I use for standard coffee makers — Costco Kirkland Colombian. It’s a medium-dark roast that’s also good for making espresso.
Many espresso machines have steam wands to froth milk. The Breville Bambino makes steaming milk extra easy.
Finally, I try to froth milk with any coffee maker that has a steam wand. I document the overall experience with the steam wand, whether the process is a breeze, a pain, or somewhere in between.
Steamed milk can be used to make espresso drinks that are similar to café-style espresso, such as lattes and cappuccinos.
