Reflections from the Coffee Technicians Guild Summit


By Marco Serri

The Coffee Technicians Guild Summit has just ended in Susegana, Italy – the first European event dedicated to technicians who daily support the coffee industry. This was an opportunity to share knowledge and experiences among industry experts. Hosted by Astoria, we had the pleasure of spending two wonderful days with technicians coming locally from Italy, as well as America, UK, Greece, Germany, and even from such far distances as Jamaica.

Right from the start, the good atmosphere between the participants made the event serene and pleasant. It was important for all those present to discuss their work and share their experiences with one another. Not only were there technicians who engage daily in coffee machines, but also owners or managers of service companies. All of them contributed to the success of the event by playing skill tests and problem solving.

Insightful and exciting lectures were presented by expert speakers, including: Damian Marshall (Urnex), Steve Murdoch (Costa Coffee), Simon Green (Bunn UK), Marco Wellinger (ZHaW), Sergio Barbarisi (BWT), and Allen Boney (RS Components).

Summit attendees were enriched by new knowledge, useful to their daily working lives. Lectures and sessions emphasized the  importance of preventive maintenance and the role of water in coffee machine use and extraction. Sessions on coffee grinders were pivotal importance in deepening the parameters involved in the extraction, understanding the different kinds and benefits of grinders, and how variations in these grinders can affect the grinding of coffee.

An in-depth discussion on the use of various cleaning products by Damian Marshall of Urnex addressed the fundamental importance of daily maintenance – not only of the machine, but also of the grinder, and Allen Boney of RS Components analyzed the measurement tools that technicians should never forget.

The CTG Summit presented a great opportunity for me to get to better acquainted with the Executive Council, of which I have the honor of being a member. I had the opportunity to discuss the future of the event with them and to explore strategies to promote the event and attract more technicians to join the guild.

Reflections and discussions regarding the organization of these events have been at the heart of the exchange of views over this two-day program. Education modules will be broken into three experience levels to span the wide range of talent in the Guild:

  1. Foundation: For new technicians approaching and entering the coffee industry
  2. Intermediate: Experienced engineers in the industry
  3. Professional: Highly experienced technicians who are faced with managerial situations

Through  future events, the Coffee Technicians Guild seeks to present opportunities to grow this network of experts, as well as to share knowledge and experiences with one another.

PID vs. Pstat

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Many of us have heard that in order to make good espresso you need an espresso machine fitted with a PID controller. The real question is, why? Is it true that a PID is the only way to achieve the temperature stability for a great espresso shot? To understand the advantage of a PID system, let’s take a look at both systems to understand how they work.

A pressurestat is a mechanical device that uses the temperature to push on a rubber diaphragm and open a switch. In practice, this means that the expanding air from the heated boiler ‘pushes’ open a switch, turning off the heating element and allowing the system to begin to cool. The pressurestat can be adjusted to open at different pressures depending on the machine in question but is typically set to open somewhere around 1 to 1.2 bar. Now the machine begins to cool via the natural process of radiation, losing heat to the surrounding environment. This continues until the pressure on the rubber diaphragm is no longer enough to hold open the switch. The switch closes, completing the circuit and turning on the heating element. Now the espresso machine heats up again until the temperature can again ‘push’ open the switch.

This whole process puts the espresso machine in a constant cycle of heating and cooling - this isn’t a secret. Espresso machine manufacturers are well aware of this heating cycle and have many innovative ways to try and increase the temperature stability of their espresso machines. These can range from adding more metal to the group head to increase the thermal inertia of the brew unit, to adding additional water flow to allow water to be mixed in a controlled ratio to help maintain an ideal temperature for extracting espresso. These technologies have varying levels of success in temperature stability but are, inarguably, necessitated by the pressurestat. Good or bad, there you have it.

The PID system solves for the cyclical heating and cooling a pressurestat causes by using mathematical algorithms to predict and counteract the thermal inertia the espresso machine experiences. If you run the hot water tap, the PID system will know that it will be taking in cool water from the fill valve and will begin to micro-fire the heating element, cycling it on and off hundreds of times a second, in order to heat the machine before it has had a chance to cool. The PID system uses a logic panel to identify variation from a set point. This means that when an espresso machine is heating up and approaching the target temperature, the heating element will ‘reduce power’ (increase the “off” time and decrease the “on” time) to less than full power so that it does not over shoot the target temperature. In a perfect world with a perfect espresso machine, this would mean that the temperature remains perfectly constant and you get the right temperature every time. Unfortunately, due to restrictions of the real world, we still see some slight variation from events like boiler filling or loss of steam pressure given that the system cannot always flash-heat water as quickly as it would like (due to heating element wattage restriction). These events can cause dips in temperature, but they are far less pronounced than they are in a pressurestat system.

If a heat to time graph for a pressurestat produces a sine-wave, then the introduction of a PID system would reduce the amplitude of that wave. Said another way, the temperature would always remain closer to the set point by a significant factor. Tighter temperature control should mean better espresso more of the time.

The question remains, is a PID controller a requirement for good espresso? In short, no. A PID system is not a requirement, though it is a boon. The tighter control provided by a PID system will make it easier to guarantee that you will get a perfect shot each and every time - it is just science. However, there are many things that baristas have been doing for eons to produce fantastic espresso using mechanical espresso machines.

One of these methods for creating consistent espresso is to run hot water out of your espresso machine until you see the heating element come on. Then, count up from there and pull your shot, say, ten seconds after your element came on. Since your element always turns on at the same temperature, and your machine should heat at the same speed every time, this will allow you to learn your machine and come very close to hitting your temperature mark with enough practice.

For many people, a pressurestat remains a good method to use to control the internal temperature of your espresso machine. For some, who have put in the time and can taste the difference, a PID system will improve your experience by either simplifying your process to get a perfect extraction or by increasing the precision with which you operate your espresso machine.

All in all, your grind setting, coffee freshness, ability to get a good tamp and cleanliness of your espresso machine will have far more effect on the taste of your espresso than will the precision with which you are able to control temperature. If you are new to the espresso world, take your time and enjoy learning about all of the areas mentioned above before you take on mastering the precise temperature you use to extract that sweet brown nectar we call espresso.

Reflections from Host 2017


Host 2017 was the most exciting Host exposition since 1999. With more than 140,000 attendees from 135 countries it truly is an international exposition. The exposition encompasses 19 pavilions offering most items for the hospitality industry from furniture, gelato manufacturing equipment, pastry cases, roasting equipment, roasted coffee, Espresso and coffee grinders, Espresso equipment and all the ancillary products including knock boxes, tampers steaming pitchers etc. The sheer size of this exposition is daunting. It is difficult to see the coffee section in in three days and I believe it is impossible to view the entire exposition in the 5 days it is open.

There were many innovative new espresso machines and espresso grinders. I have not witnessed this many new exciting concepts regarding espresso and grinding equipment in a very long time. Many of the manufactures are offering the latest in profiling as well as very hip designs. 

The Coffee Technicians Guild was a large part of the buzz at Host. Everyone that we visited showed great interest in supporting the training and collaboration aspect for coffee machine technicians. We had manufactures offer meeting space for the executive council in Barcelona and Italy as well as offer to help move the guild forward. 

Shad, Jason, Lorenzo, Damian and Gene visited many Espresso machine manufactures, part suppliers and grinder manufactures to introduce the CTG. All are willing to join and would like to be involved going forward. The response was amazing! 

The CTG had Three mixing events at Host. The SCA lounge of Friday, the Astoria booth on Saturday and the Urnex booth on Monday. A big Thank you to all the hosts. It was great to meet new people and introduce the CTG to the event attendees.

The 2017 Host exposition will go down history as one of the most innovative expositions. Hope to see you all there in 2019.

Best regards,

Gene A. Lemos


Nuova Ricambi USA

Member Spotlight: Leah Ellis

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My name is Leah Ellis and I’m the owner of JavaTech Mobile Espresso Equipment Repair in Snohomish, WA.

We got our start back in 2010 in Georgetown, which is an old Seattle neighborhood. Unless, that is, you want to go way back to the 1990’s and our first good espresso at Carmel Coffee Company in Carmel-by-the-Sea. We tried our first mochas and lattes in their sunny grotto as the butterflies danced in the late summer blooms that hung from the walls of their courtyard. I’m sure as enchanting as it was, it gave us our love for the industry.

Fast forward some 15 years. My dad and brother were bicycle mechanics at our family-owned bicycle shop in a small town outside of Seattle called Spokemotion Cycles (we are directly related to the Wright brothers, who were bicycle mechanics before they built their first airplane – ironic, huh?). My dad had an old friend of some 50+ years with a warehouse in Georgetown that had an espresso stand in the parking lot whose machine needed repair. He called my dad, as everyone does because he can fix most anything, and asked if he could repair it. My dad gave it a go and that’s where our journey began. My brother and dad (our inside and outside techs) took the Beverage Equipment Service Technician Training Program and all other available trainings that we could get our hands on and set out to offer a helping hand to the Seattle-North machine owners. Since then, we’ve expanded our reach, upgraded our vehicle and gotten to know many fabulous people, many of whom we consider friends. We’ve been out late at night, early in the morning and on holidays. We’ve worked on just about every machine under the sun and certainly developed our favorites (which we’re happy to recommend as we’ll be repairing them on our next visit).

My role is owner, public relations, accounting, dispatch, customer service, parts pick-up, and drinking some of the finest mochas (my personal favorite) that this region has to offer, while chatting, problem-solving, and learning with roasters, stand owners, baristas, machine manufacturers, and anyone else in the industry that I can find to talk to. Tribal knowledge is the best way to learn and I’m always learning.

I’m really glad that the CTG will be bringing us together and standardizing the industry in the area of Coffee Technician training and certification, which is badly needed. What a ride this has been, and I’m looking forward to learning from, chatting and meeting with and enjoying getting to know others in the Coffee Technician world.