My process for evaluating home espresso machines is similar to how I test standard drip coffee makers. First, I hand washed and dried all removable parts and accessories. For most espresso machines, this includes the filter basket, metal handle, water tank, etc. Next, I run a brewing cycle with just hot water to flush away any leftover material from the manufacturing process.
Most automatic espresso machines, with the exception of the fancy super-automatic models, lack an integrated coffee grinder, and I prefer to test espresso machines with freshly ground coffee rather than pre-ground coffee, so I’ve included my own grinder: Breville Smart Grinder Pro. I chose this conical burr grinder for two reasons. First, it’s calibrated more for espresso than for drip or other brewing methods. This means it produces coffee beans that are ground very well. Secondly, its grind size is always uniform. Both factors are crucial to a proper espresso brewing process.
To set up the shoot, I started with the recommended methods outlined in the product manual for a given machine. Typically this covers the amount of coffee grounds expected per shot, as well as any guidelines on roughness levels. Likewise, if the manual provides tamping instructions (light, medium, or heavy pressure), I follow those instructions.
Whenever possible, I brewed a double shot of espresso in all my tests. I make sure to record the weight of the ground coffee I use, as well as the weight of the espresso I brew each time. This data, along with the readings from the portable refractometer, allowed me to calculate two important percentages: total dissolved solids and extraction percentage.
As with any coffee brew, the ideal extraction percentage for espresso is between 18% and 22%. Assuming you extract the coffee compounds (flavor and caffeine) evenly and efficiently from the grounds, this will produce a balanced cup of coffee.
Not many home espresso machines can brew high-quality coffee. This is pulled from Breville Barista Express.
If you over-extract, you run the risk of leaching out unpleasant flavors (bitterness) after extraction. On the other hand, under-extracted beers tend to have untapped flavors. Due to the lack of sugar and other caramelizing organic chemicals, these products will taste sour, bland and watery.
Unlike a cup of drip coffee, barista-quality espresso should be concentrated. Premium drip coffee typically has a TDS percentage of 1.3% or 1.4%, with premium espresso having a much higher percentage. For example, Breville Barista Express produces coffee with a TDS percentage of 12.4%.
The shots I pulled were well balanced and had an extraction rate of 18.6%. The test coffee beans I used are the same variety I use for my standard coffee maker – Costco Kirkland Columbian. This is a medium dark roast that is also suitable for brewing espresso.
Many espresso machines come with a steam wand for frothing milk. Breville Bambino makes warming milk especially easy.
Finally, I tried frothing milk with every coffee maker that has a steam wand. I document the overall experience of using a steam wand, whether the process is a snap, a tricky chore, or somewhere in between.
You can use steamed milk to make café-style espresso drinks like lattes and cappuccinos.
