Rocket Bottomless/Naked Portafilter

The Rocket Bottomless/Naked Portafilter

When I received my newly purchased Rocket Evoluzione v2 espresso machine - I had the pleasure of receiving a bottomless/naked portafilter from Rocket, which gives insight of your tamping technique and the general extraction flow than a normal closed portafilter.

The naked portafilter is a useful tool that has utilization in both café setting and especially for the home enthusiast. In theory a naked portafilter is exactly the same as a normal portafilter handle, with the spouts removed, showing the bottom of the basket that holds the compressed coffee. Having the basket exposed means that you can watch the entire extraction process, and diagnose any problems with the shot extraction. This sounds complicated, but its really not.

Keep in mind that to create a quality espresso or ristretto, you need water to be pushed evenly down through the basket of coffee. If the shot is coming out unevenly its said to be channelling, which can be seen easily with a naked portafilter as the water will pour from the side of the basket rather than brought the middle.

Preheating the Portafilter

I start by running some hot water through the portafilter to ensure that it has been heated properly.

Extraction diagnose:

• A very blond (light) shot may be an indication that you need to dose more coffee in your basket or perhaps your grind is to coarse. 
• A very dark shot is caused by the opposite, dosing to much coffee or grinding your coffee too fine.
• Uneven tamping will cause channelling and thereby leading the water trough the path of least resistance. You will be able to see blonde patches, which indicate where the coffee is not compressed as tightly or where less coffee is distributed.

The color of the shot you pull through the naked portafilter can also be a good indication of whether you are getting it right, a perfect espresso shot should have an even, golden to reddish brown color that starts to blonde (lighten in color) around 25 to 30 seconds in the brewing process.

The steps within the extraction process - see the pictures separately on the CC Facebook site!

The shot shown above reveals an uneven tamp, but great extraction - taking into the blond phase of the shot. This kind of shot will maybe never reveal itself to the common amateur coffee enthusiast, but for those who master the right technique, this shot will be a medal of self-confidence of the highest coffee level. For those whom are not gifted in the art of extracting, a naked/bottomless portafilter is properly the best way to go.

The final brewed shot

From a taste point of view, there are more then a few opinions whether the naked portafilter affects the flavors versus the standard portafilter. In my opinion I have seen an increase of produced crema which also is more airy and therefore makes it more suitable for latte art. The flavors are more cleaner than an extraction that has to run through a portafilter spouts.

Don´t forget that enjoying a cup of coffee is a subjective experience, everyone has a different personal taste and preference, so keep this in mind when you hopefully are experimenting with the naked portafilter.

// Hendrup