What is Scott Rao’s Production Function?

ECRE
5 min readFeb 16, 2021

Author and consultant Scott Rao has influenced how specialty coffee pros roast and brew coffee more than anybody else over the last two decades. What’s his secret?

There’s this (rather nerdy) podcast I listen to called Conversations with Tyler in which the host, famed economist Tyler Cowen, interviews all sorts of smart people from various walks of life. It’s mostly standard podcast fodder except for one particular question that he asks all of his guests. The question is “what is your production function?”

What Tyler means by that question is “what’s your secret for being so immensely productive? How do you manage to consistently create groundbreaking work in your domain of expertise?”

It’s an excellent question that always gets interesting answers, and it’s something that I’ve wondered about in relation to one of coffee’s great thinkers and innovators, Scott Rao. Through multiple books and influential blog posts, Scott has repeatedly introduced radical and influential techniques, models and concepts into the worlds of roasting and brewing. These ideas, such as paying attention to a decreasing rate of rise while roasting, aren’t always embraced swiftly and universally, but many of them have shown to have enduring usefulness.

So how do you do it, Scott? PLEASE TELL ME.

This is pretty much what I asked Scott during our conversation on the ECRE Academy Coffee Podcast, and I found his responses extremely insightful. Here are some of the takeaways:

Scott knows how to think like a scientist

Scott will be the first to tell you that he is not a scientist, and his experimentation in coffee does not constitute ‘scientific research’. However, he does understand how the scientific process works and it clearly influences how he thinks about designing experiments and drawing conclusions from them. As per the scientific method, Scot believes in testing falsifiable hypotheses, letting the data guide your inferences, and keeping an open mind.

He also knows enough about science to know that building roasting techniques by attempting to apply theories borrowed from thermodynamics to coffee roasting is, at least at this stage, a fool’s errand.

“I’ve never looked at roasting as [a heat transfer problem] because I think it’s too hard. I don’t think we know enough about the science to take that sort of top-down approach. Instead, a better approach to take is sort of a ‘big data’ approach where you do lots of roasts on lots of machines and think ‘ok, what’s working?’ and start from there.”

He has a clear vision of what he wants to contribute to the industry, and it has more to do with engineering than straight-up science

“I’m not a scientist, like my friend Jonathan Gagne [the coffee nerd astrophysicist]. I don’t write coffee science. I write systems. I want efficient, repeatable, verifiable results–to figure out how to do that. That was really the focus of all of my books.”

When thinking about the value of coffee and the coffee industry, Scott has his priorities straight

Scott worked full-time on coffee bars for many years, and he loves it. As he told me, he feels that “the heart and soul of the coffee industry is still serving beverages to customers. That’s the thing that drew me into the coffee industry–the energy and interaction. I felt like we were the heart of the community in that town where I opened my first coffee shop. Quality coffee was just the method to bring people together.

He has worked HARD throughout his career

In his first cafe, Scott told me that “I would work from 7:30am until midnight every day, and after closing and cleaning up, I’d be desperate to do a little experimenting, so I would stay back an extra hour to do it because, for me, that’s where the juice was. It’s what I loved. I love problem solving.”

And obviously, he was (and is) incredibly passionate about improving coffee. When David Schomer released the book Espresso Coffee: Professional Techniques, Scott was so excited that somebody was actually writing about brewing that he called him up, never having met him before.

“I remember being like, ‘I’m going to call this guy! We’ve got stuff to talk about’. He was somebody thinking about coffee and systems and that was exciting”.

When trying to solve problems, Scott relies on lots of data and an open mind

I was surprised to learn that when Scott devised his theories around development-time-ratios (DTRs) and a steadily decreasing rate of rise (RoR), Scott did not start from a theoretical concept around how to optimally apply heat and then tested it out on the roaster. Instead, the idea came to him while consulting for a large coffee roaster:

“I had stayed up all night looking at their roasting date (which was on spreadsheets, they didn’t have Cropster) and I came up with a few ideas which eventually culminated in the idea of the DTR and steadily decreasing ROR. So aimed for that the next day, and it worked really well. The owner sat down with a cup of the coffee roasted that way and said to me ‘you know? I never knew my coffee could taste this way.”

(if you’re a roaster and don’t know what I’m talking about here, stop reading and buy this book. Now.)

Consulting allowed Scott to work on many different types of roasting machines, and this helped him test whether his models worked in a range of scenarios

Scott understands that it takes a lot of testing to claim that a particular roasting approach will be helpful across different machines, coffees and batch sizes:

“When you roast on one machine for a while, you start thinking ‘OK. This is true, and this is true, and that is true’. But when you go and roast on another machine you’ll realise ‘oh wait! these ideas aren’t true’. This really opened my eyes and made me want to parse what is universally true for roasting and what is incidentally true for a certain machine”

Scott is humble about his theories and therefore flexible enough to change them when they’re not working

“A lot people out there think that because I give out unsolicited advice that I’m an egomaniac [laughs], and i don’t really care. I’m genuinely OK with being wrong and I know that I’m going to be wrong incredibly frequently, and that everyone is. What’s great about science is that it constantly fixes itself. It’s like “oh, we were wrong. Here’s a new and better hypothesis.” I’m also excited when I’m wrong and I get to learn the better seeming truth each time. My goal is to make better coffee, not necessarily to look good along the way.”

To listen to our chat, search ‘ECRE’ in your favourite podcast app or click here. If you’re in Aus and want a copy of Scott’s books, check out the ECRE store.
Here are links to Scott’s site and instagram.

Piece written and podcast hosted by Tuli Keidar

--

--

ECRE

ECRE. Co-roasting, coffee academy, store, and events. 👉🏻 Sydney, Australia. http://ecre.coffee