If you follow these kinds of things you will be aware that the Nuova Simonelli Aurelia is the new competition machine for Baristas. When the question of sponsors for the WBC has come up in the past, people wanted to know if any company other than LaMarzocco would ever have their machines used in competition. The answer seemed to come back that if anyone else’s machine could pass the WBC’s strict temperature stability prerequisite, they would be considered for the machine sponsorship. Many machines on the market now boast either dual boiler or some other technology intended to maintain a constant brewing temperature. One can assume that the Nuovo Simonelli Aurelia delivers the temperature stability that they claim.
If you look at the transparent view they provide on their website you can see just enough confusing imagery to get that they do not want you to understand how they achieve stability in any real transparent way. The description explains the following about each group: they weigh 12 pounds each, they hold a liter of water, the brew water passes though a heat exchanger, there is only one heating element. This is how I believe it is designed to function (my best guess anyway). Water that is heated by the heat exchange is passed into the one liter reservoir located inside the group itself. The massive group is gently heated by siphoning water from the steam boiler. Because it takes so much energy to change the heat of the group and reservoir, the temperature remains relatively constant.
I had the opportunity to test an Aurelia with a Thermofilter. The machine had been idle for at least 15 minutes when I started, and I flushed the group to listen for any signs of super heating. The water came out with a hiss, which lasted for as much as 20 seconds. A traditional heat exchange might have hissed for half this length of time (at least from my experience). I flushed for another 10 seconds and found the temperature to be 209F, still to hot for good extraction. Another 10 seconds of flushing brought it down to between 198 and 200. There was a gently inclining temperature profile over the time of the shot.
Once the machine was brought down to a desirable temperature it did maintain it very well. If the machine stays in constant use it will stay relatively stable. A couple of idle minutes, however, and it was back to 209. There is a lot of flushing needed to keep it within brewing parameters if there are interruptions between coffee prepartion. There is a steep learning curve with the Aurelia, as with any heat exchange machine. One must use it a lot and taste the coffee it makes a lot and become intimate with it to get what one wants from it. The winners of the Barista Competitions coming up will be Baristas who have spent time testing heat exchange machines. The winner of the WBC will be someone who spends a lot of time with the Aurelia and a Scace device and really learns the proper flush times. The massive groups give up heat reluctantly, which is both the advantage of and the Achile’s heal of the Aurelia.
This makes me wounder if the WBC has rigid temperature standards at all. If this is the new competition machine then it seems obvious that they do not. I can’t say that I blame them for going with Nuova Simonelli though. It is terribly expensive to put on even small competitions, and the head sponsor has to flip an enormous bill. The competition machine will be form the one that offers the largest kitty, not the one with the easiest machine to use. This will weave out the Baristas that have been raised into the coffee industry with equipment that is so good that they have not had to learn some basic lessons in brewing equipment management. The winner will be an even better Barista than one who simply expects the machines to do the brunt of the work for them. I know that great coffee can be made on heat exchange machines, but it takes a great Barista. This year the cream will not rise to the top until after it has passed through a strainer.