/ #rocket espresso #dual boiler 

Rocket R Nine One Review

Quick Shot

Our less than 30-second look at the R Nine One

  • Stainless Steel Dual Boilers
  • Pressure Profiling (Manual Paddle & Preset)
  • Plumb / Tank
  • Fully Saturated 58mm Group
  • Timer Auto On/Off (2x/day)

Trying to sum up Rocket Espresso’s latest home espresso machine is almost impossible in any concise manner. With such a feature-rich pressure profiling espresso machine we have to dig a bit deeper. To illustrate the quality of this machine, and the cup it produces, in brief - Andrew from Rocket said it best.

“We had a GS3 in the house…it made an exceptional cup…when it left no one said anything…when the R Nine One went to the office, everyone was asking where it went.”
- Andrew from Rocket

When you put this machine on your counter, you’ll feel the build quality. Weighing in at a hefty 105 pounds, the R Nine One is as heavy as it is feature rich. The R Nine One takes Rocket’s level of attention to branding and applies the same to build quality - even more than previous models. The frame, fully saturated group, many internal parts, body, and many more features are stainless steel or a fully treated metal.

As a custom option, similar to the La Marzocco GS3’s and Linea Mini, the R Nine One’s body is customizable with multiple finishes, a rubber finish in either white or black can be applied to the R Nine One’s side and rear panels for a sleek and more modern look.

Dual Boilers

One of the first things expected would be the highest quality brew and service (steam) boilers on a machine of this caliber. The AISI 316L stainless steel boilers ensure the longevity of your R Nine One for years to come. We do suggest that with the stainless-steel boilers, similar precautions taken with the La Marzocco machines are followed with special attention made to reducing chlorides in your water.

Fully Saturated Group

As your shopping for home espresso machines, you’ll notice that with many on the market you are more likely to find an E61 group on the front of it, than not. The reason for this is the patent on the E61 has been up for years, and it’s a reliable and easy way to build out your espresso machine. The only problem with E61 groups is that temperature stability is suspect. The E61 group was initially built for heat exchanger machines where loss of heat for brewing was integral to making a proper cup. With the advent of dual boilers, the E61’s heat loss through the thermosyphon heating is not ideal.

A fully saturated group is one of the most stable group designs. While each is registered per manufacturer, all fully saturated groups follow the same concept. The group is placed within the machine and as close to the boiler as possible in many cases. Reducing the amount of space the heated water has to travel reduces the amount of temperature drop from the boiler to brew or steam.

Offset Differential: the difference in internal boiler temperature and brew temperature at the group

Other home espresso machines with a similar group configuration:

Pressure Profiling

Baristas and home espresso machine users alike are always playing with the most basic variables of the perfect cup. One of the recent trends for machine manufacturers is pressure profiling.

Pressure Profiling: controlling pump pressure at various stages of the brew process to expose different aspects of your coffee

The R Nine One boasts some of the most advanced controls of your brew pressure in our entire line-up. There are two ways of operating the R Nine One’s brewing temperature. 

  1. By preset profile, which there are five available, and fully customizable presets. Your brew lever in this case is a light switch. No matter where it is positioned the machine is on, follows the pre-set, and then you turn it off.

  2. There is also the ability to manually, in real-time, control the brewing pressure. In this case, you’re taking full control of the brewing process in both time and pressure at that time. Also in this case, your brew lever is like a dimmer switch or a potentiometer.

Potentiometer: a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider (source)

What happens if you like what you taste after manually brewing?

If your manual operation of the brewing process resulted in a great cup, you could save that as a preset for future brewing easily accessible by the LCD screen.


Chris' Coffee Staff

Starting out of the back of an El Camino with the help of my family and a couple off duty cops, Chris' Coffee Service has been the experts in coffee since 1975.