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Longtime Espresso Pro Michael Teahan on Pre-Infusion, the Problem with SO, and Much More

espresso shot

Espresso at Kahvila Sävy, Kallio, Helsinki, by protographer 23. Licenced through: ShareAlike 2.0 Generic (CC BY-NC-SA 2.0)

[Author’s note: Back in September 2018, I spent a good hour and a half on the phone with Michael Teahan. The interview was incredibly fascinating, but after transcribing, it was almost 20 pages. With this interview, I tried to capture Michael’s lengthy career in our industry and some of his well-respected technical prowess.]

Hylan Joseph: What I’d like to hear from you is your history.

Michael Teahan: I was working for a public interest research group. My degrees are in economics and political science and I was about to change the world when my roommate’s daughter, who was going to school in Seattle, suggested that [I] should do something in coffee because it was really taking off in Seattle. And at the time I think there were six Starbucks locations. This was back in 1987. So, we kind of fiddled with it for a while, tried to poke around and see what was going on and I got on the phone with Mike Myers from Michaelo Espresso and asked him if he had any distributors for espresso equipment in Portland, and he said no. So, we rounded up our first espresso machine to fix, threw it in the back of the car, drove up to Seattle and had Russ Meyer show us how to fix it. And that’s how I got my start, essentially.

I grew up in a transmission shop, so a mechanical background was easy for me. I’ve only bought one new car in my whole life and everything else I would fix, paint, [or] do whatever. I was a grease monkey. So equipment was pretty easy and I had a knack for it. We started selling espresso machines in Portland back in the late ‘80s and then started designing some of the first espresso carts in Portland and started manufacturing a few of those. I was working with Nordstrom at one point — they were actually building their own carts but I was providing the equipment for them. So just the typical early start, trying to educate people on coffee. At the time we were having difficulty selling people on espresso because the liquid espresso guy made a run through Portland and set everybody up with his liquid concentrate and free espresso machines.

And it was like every other day I would get someone on the phone and they would say, ‘oh, we’ve tried espresso before and it just didn’t work out for us. Are you giving us a free machine?’ And, of course, the answer was no. So those were some of the challenges. And I was basically a distributor for equipment on our own in Portland so we had to figure all that stuff out. My second service call was taking gaskets out of an old Gaggia that hadn’t had the gaskets replaced in 10 years and it took me four hours to get them out. I really questioned my career choices at that point.

HJ: About how old were you when you were at that level?

MT: I was 28.

HJ: Where did you land for the longer extension of your career?

MT: I was still a distributor working into the ‘90s. I had some degree of respectability for understanding how espresso machines worked. I was doing some technical manuals for them, doing some training seminars for them, trying to sort out issues that they were having with some of the espresso machines that were coming in at the time.

HJ: I understand you came from the restaurant business? What was it called?

MT: It was called Caswells in Portland.

HJ: What made you decide to get out of it?

MT: It’s a lot of work and, unless you want to sell pizza and beer all day long, you don’t necessarily make a lot of money.

HJ: Walk our readers through pre-infusion.

MT: Pre-infusion is a method of pre-soaking all the water that’s in the puck at a reduced pressure so that the grounds are evenly saturated to mitigate any effects of channeling. And it does it at a lower pressure and, ideally, a slightly higher temperature. And then when you actually begin the extraction process, if the grounds are fully saturated, channeling is essentially eliminated and, if you achieve that lower temperature during the extraction process, then you get a more complete extraction. Because the coffee that’s in the portafilter is actually room temperature — about 70° or 75°, depending on where you are. So the average temperature of the saturated puck isn’t at that ideal 196° or 198° or whatever you want to choose during the initial infusion. So if you come in a little bit hot, you can kind of stabilize and equalize the temperature of the puck so that when you actually extract, you’re getting a better extraction.

That was around 2000. One of the things that we did when I was working with Brasília, and the whole pre-infusion thing was coming around, was that I had Brasília build a custom machine for us. I tended to favor the mechanical pre-infusion systems because each group could be independently pre-infused. They developed a machine for us that, with a switch, you could actually use a solenoid to turn on and off the pre-infusion system.

We sent a machine up to Starbucks for them to test. I arrived the next day and the machine was almost completely taken apart, and they had a Marzocco temperature probe, like the one that’s built into the portafilter. They locked it in a group and they were running water out of it, and they had no idea how heat exchange machines worked. They kept saying, ‘the machine is too hot, the machine is too hot, we can’t get it to cool off.’ And I said, ‘What have you tried so far?” and they said, ‘we have the pressure set as low as we can go, down to .9 bar, we opened up the steam valves for like half an hour, we can’t get it to go below nine bar.’

I took them aside and said, ‘First, you have an espresso machine that you can run for half an hour and not run out of steam. Isn’t that what you’re looking for because you work with a lot of milk?’ And they agreed. I also asked them if they had actually taken the time to actually brew a shot of espresso out of it. And they hadn’t.

One of the frustrations that I’ve always had when working with Italian engineers and American pseudo-engineers is that, with Americans that are not really understanding what’s happening inside of an espresso machine, they always default to temperature gauges and stopwatches and timers and data. They’re trying to analyze everything within an inch of its life without really understanding the process.

There are numerous times where I’ve shown up to do a test and someone pulled a thermometer out of their pocket and stuck it under the stream of water and immediately invalidated the machine because there was no way that it could produce espresso, never having actually pulled a shot. So it was kind of that battle.

Whenever I had the chance to go to Italy, I would find engineers, even if they didn’t speak English, and pull them aside and have them show me stuff. What is taken for granted as, ‘that’s just how we’ve always done it’ in Italy was not even discovered here.

Basically, my background in engineering has to do with my being exceedingly curious and wanting to probe what the Italians considered to be their ideal — or what they were thinking, what they were doing — trying to find little clues here and there. I sat down for about half an hour with a gentleman by the name of Gianni who was rumored to be one of the guys that originally developed the 61 group. I can’t say for sure, but even with my limited understanding of Italian, I kind of got more out of that interview than I got out of a lot of things. A lot of it was just observing problems with equipment. Why stainless-steel boilers suck, for example.

 HJ: You’ve been vocal about stainless-steel boilers. Why?

MT: When a boiler gets hot in an espresso machine, the top of the boiler does not get hot because there’s steam in it. The top of the boiler gets hot because heat is conducted from the water in the bottom of the boiler, through the boiler material itself, to the top of the boiler.

Because the thermal transfer of heat energy through the water is actually relatively poor, you have to keep circulating it and circulating it around the metal. Steam is even worse. Almost no heat energy is transferred from steam to metal very efficiently. But in a typical copper boiler, it’s almost instantaneous. It’s very, very fast.

The speed at which heat transfers through copper is huge. I used to blow glass when I was in college and we would take these 4.5-to-5-foot-long stainless steel pipes and we would stick it into a furnace with 2000° glass, we’d get it on the end of it and we’d start spinning it around and we could actually put our hands, within about a foot of where this 2000° glass was, manipulating a stainless steel rod. And it got warm, but it never really got hot.

Stainless steel, in terms of heat conductivity, kind of sucks. If that had been a copper pipe, it would’ve been about 1500° at the other end of that copper pipe. Stainless steel boilers work in some machines because they’re small and there’s actually a thermal transfer, like an ocean thermal gradient that happens inside the boiler. But large stainless-steel boilers are kind of difficult that way.

 HJ: Yeah, we all know about that.

 MT: Actually, the company at the time that actually won the standards was Brasília.

HJ: I did not know that.

MT: Yeah, but they were disqualified because the machine that they entered was deemed to be a prototype. But what they didn’t understand about Brasília is that basically every machine they build is a prototype. You want it done this way or that way? They don’t care, they’ll build you 100 of them, it doesn’t matter. So they were disqualified.

But their temperature curve was absolutely flat. It was their new Red Bolt brewing group with an oversized infusion chamber and different jetting. And second place was the Aurelia, third place was the Marzocco. And that’s what I’ve been told. So I didn’t get it firsthand, I got it second hand.

But at the time, Brasília put together an ad in their marketing department where they were comparing their new Red Bolt design in terms of temperature stability against all the other machines on the market. They were using soluble extraction rates on coffee, like an actual chemical analysis. They had it all mapped out and all graphed out six or seven different machines.

But there was one red line that was above everybody — and it wasn’t assigned to a manufacturer. The pitch was that that red line was the old lever traditional espresso machine — and their pitch was that they were closer to that red line, which no one had yet been able to hit, than anyone else — and I was more attracted to that red line.

All of the new stuff — whether it’s temperature profiling, pressure profiling, pre-infusion systems, different kinds of dynamic versus static pre-infusion — all of these things are an effort, in some way, to replicate what happens in an old piston group that was designed in the late 1940s.

When I was talking to Paul Pratt — this is like 10 years ago — and he was doing all this PID controlled Marzocco modifications of things like that, he started getting into restoring old espresso machines and he came across a 1955 or ‘56, I think, lever machine. He restored it, put it on his bench and it had the old Mercury pressure switch and he kept saying, ‘I don’t understand this machine because I’m getting temperature variations of 6°, 7°, 8° all the time. Up, down, doesn’t matter. It’s all over the map. But every time I pull a shot on this machine it’s better than anything else in my shop. And I don’t understand why.’

I understand why, but at the time he really didn’t quite get it. [It’s] ecause there are a lot of interactions that happen in an espresso machine. For example, when you have a heat exchanger machine, when you get temperature fluctuations at the brewing group, the flow of water through the heat exchanger into the group speeds up or slows down based upon the temperature differential between the boiler and the group itself. So, in a sense, it’s modulating temperature dynamically all the time without the use of electronics. And how you jet it and how you pipe it makes all the difference.

You can take an old-fashioned espresso machine that’s 30, 40, 50 years old, and if you map it right and tune it right, it will make a shot of espresso every bit as good as all of these really expensive machines, but you don’t get any flexibility. You can’t change your mind. You can’t change a temperature profile based upon a different kind of coffee, [or] you can’t change a pressure profile based on different levels of roasting. But with the ability to make those changes comes a requirement that you understand what those changes do.

There are so many tools now in the hands of technicians and baristas to play [with], but I think a genuine lack of understanding of what’s actually happening when you make those changes. So on the one hand, I think all the new tech is really cool. But since I’m almost 60 years old, and I’ve seen a lot of it — I have a small coffee bar that I have an interest in South Glendale — the machine that we have on the counter is an old lever group machine because I just love them.

HJ: You’ve been around to watch the third wave come into play. What are your thoughts about making coffee, like doing the first crack roasting and the more fruity, citrusy coffees?

MT: We tend to make fun of everyone’s trying to come up with different ways to describe the flavors in coffee — all the mango and chutney and banana and all this other stuff — and it’s kind of like when wine got popular again and everybody was tasting all these different wines. Absolutely those flavors are there, but because everything that’s old is new again and we’ve seen all these different transformations in coffee.

My take on the third wave is that everyone is trying to find something new. Everyone is trying to find a different way to find flavors and new innovations, new anything and reinvent themselves a little bit, which I think is really cool, but I also think that it shuns a lot of the history and a lot of the tradition — like on the espresso side, because my side is mostly on the espresso side — of what I think espresso should be.

I’m not a fan of the light roast for espresso because it’s too monochromatic. Single-origin espresso I’m not really interested in because there’s this one flavor profile that comes through and I’m looking for something that’s more balanced.

The difference between Italian roasters and American roasters — and this is no dig against American roasters, and I know this is going to come across that way — is that Italians will typically blend for a particular taste that they want. The composition of that blend will change monthly if necessary because, as coffees change and evolve, you have to change the blend and the roast characteristics to achieve that same flavor profile that you’ve had for the last 50 years — and there is an art to that.

In the US, with this emphasis on single-origin, we’re exploring all these different flavors from different coffees that nobody ever had a chance to explore before, but we’ve kind of lost the art of putting those flavors together for a specific result. My running joke with people who I can make this joke with, it’s kind of like going into a restaurant and someone serving you a single-origin carrot that’s been steamed lightly versus an actual meal that’s been put together by a chef that has all these flavors that are put together and developed.

HJ: We used to have a joke in the restaurant business, ‘what’s the difference between chicken and free-range chicken?’ And the answer was about three dollars on the menu.

MT: That’s right. Absolutely right. So yeah, I think the third wave is interesting and I think so many things come and go. First, espresso had to be dark, and then espresso was too dark, and then it had to be even darker still, and then it couldn’t be that dark, and then boilers had to be big, and then heating elements had to be bigger.

HJ: Last question is, you’ve been to your first CTG event and you’re getting more involved with the guild. As someone who comes to the table with your history, what do you think of the guild and what do you think that it’s potential is?

MT: I think its potential is great. In part because we have an opportunity to talk to technicians, and hopefully more than just technicians, about what’s really happening inside an espresso machine. [It’s] not just how to wrench something; not just how to remove a solenoid valve; not just tips and tricks on how to adjust a grinder.

But when you get a bunch of people coming together, you can actually talk about the philosophy. Not so much the philosophy, but the thermodynamics of what’s going on and why you’re trying to do what you’re doing — what’s actually happening to the coffee and how everything is connected. Everything is a system. It’s like this workflow from point A to point B and they’re all working together to get the end result.

I think that when technicians have been trained, historically, it’s, ‘How do I remove the group from this machine and replace it? How do I change an electronic box? How do I change a heating element without breaking the studs off of it?’ [without] really understanding what’s happening inside the machine. And I think that the same thing that was done for the barista community in terms of elevating their craft and elevating their profile, can be [applied] to the technician community.

So, it’ll no longer be a situation where you simply call up the roaster and they send a guy out who adjusts your grinder for you and tells you that, yeah, your espresso is fine. But it’ll be the technician that comes out and sets up the machine for you and asks you questions about what kind of profile you want and what do you want out of your coffee. The technician isn’t just replacing parts, they actually have a level of understanding about the equipment and the business, and what that machine can do for you and your business. It may not exist right now.

Otherwise, if all you are is a mechanic wrenching on machines, and you don’t have a love for the equipment… and a basic curiosity of how things work and how things bind together, [then] technicians are going to flow in and out of this industry and move on to something else. If they’re not passionate about what they’re doing, they’re not going to stick with it long enough to be proficient, I don’t think. So, there’s a little bit of that. You’re in the coffee industry. Whenever I tell anybody what I do, it’s like, oh, that’s fascinating.

HJ: They’re like celebrities. I used to DJ and I’m always surprised. I DJ’d in the ’80s and it was a job for me. I was a cook and I was a DJ and I never actually thought it was cool, I just wanted to play music. But it was always like, ‘wow, you’re a DJ?’ And now I talk to my daughter’s friends and my daughter is like, ‘yeah, my dad is in coffee.’ And it’s like, what do you do?… You see this generation of high schoolers that are so familiar with the culture that we came up in… I was reminding my daughter that in 1994, 70% of America did not know what a latte was. And really because of what Starbucks and Peet’s brought to the table, it’s become such a cultural powerhouse.

MT: Yeah, and it’s so foundational now that coffee bars like Blue Bottle and Intelligentsia, this third wave of coffee bars, they now have the freedom to explore things in the coffee industry that they never could have before because there is that foundation of specialty coffee here.

[Editor’s note: This article is appearing as part of an unpaid editorial collaboration between DCN and the Coffee Technicians Guild. It was originally published in the CTG blog and is republished here with permission. It has been shortened and edited for style and clarity.
The Coffee Technicians Guild (CTG) is an official trade guild of the Specialty Coffee Association (SCA) dedicated to supporting the coffee industry through the development of professional technicians.]