Maybe you think you know about roasting coffee, about how heat transforms a green bean into something transcendent, but you don’t. Or maybe you do! Let’s find out.

Maybe you’re one of those people who has spent countless hours hunched over a drum roaster, watching the beans change colour like some kind of crazy alchemist, and if so, I apologize for assuming. But probably you don’t. Probably you’re like me, five years ago, thinking that roasting coffee was just about not burning it.

Hint: It’s not just about not burning it.

Here is what happens when you decide to really learn about customizing roast profiles:

1. You realize that everything you knew was wrong.

Not just slightly wrong, but fundamentally, embarrassingly wrong, like thinking the earth was flat or that your high school girlfriend really would wait for you while you spent a year trying to start a punk band in your garage. The bean, it turns out, is not just a bean. It’s a universe of possibility, a complex devil of cellular structures and volatile organic compounds and some actual magic.

2. You start to notice things.

Things like:

• The way Ethiopian Yirgacheffe beans crack differently than Colombian Caturra
• How Panama Gesha needs to be coaxed through the Maillard reaction like you’re trying to talk someone off a ledge
• The specific sound of first crack, which is exactly like popcorn popping except when it isn’t

And you become obsessed with these things, these tiny details that nobody else cares about, because suddenly they’re everything. You start keeping notebooks filled with roast profiles, temperature curves drawn with the kind of attention usually reserved for planning bank heists. You wake up in the middle of the night thinking about rate of rise during first crack.

Don’t worry: This is normal. Or at least, it becomes normal.

The thing about customizing roast profiles for different varietals is that it’s both incredibly simple and impossibly complex. Simple because it’s just heat plus time plus beans. Complex because those three variables can combine in approximately infinity different ways, and most of them are wrong.

So, here’s what you need to know:

Every varietal has its own personality. Its own hopes and dreams and fears. (Okay, not really fears, they’re just beans, but stay with me here.) A natural process Ethiopian needs to be treated differently than a washed Colombian, not because one is better than the other, but because they’re different. Like how you wouldn’t use the same approach to babysit a toddler and a teenager. Same basic job, completely different execution.

You have to learn to listen to the beans. This sounds crazy. It is crazy. But it’s also true. During the roast, they’ll tell you what they need:

• The first crack will be loud or soft, scattered or concentrated.
• The colour changes will be fast or slow.
• The smell will shift from grass to bread to chocolate to fruit.

And you have to pay attention to all of it, all at once, while also watching:

• Temperature (both bean and environmental)
• Time (both total and between stages)
• Rate of rise (which is never constant)
• Airflow (which changes everything)
• Your own growing panic as you realize you might be ruining $50 worth of premium beans

But here’s the secret (which isn’t really a secret because everyone knows it but nobody wants to admit it): You’re going to mess up. A lot. You’re going to ruin some really expensive beans. You’re going to produce roasts that taste like cardboard, like burnt toast, like broken promises.

And then, one day, you’ll get it right. You’ll hit that perfect development ratio for that specific varietal, and the coffee will taste like everything it’s supposed to taste like – the terroir, the processing, the variety – all of it will be there in the cup. And you’ll think: This is it. I’ve figured it out.

Hint: You haven’t figured it out. Nobody has figured it out. That’s what makes it interesting.

Because every batch is different. Every bean is different. Every roast is a new opportunity to get it spectacularly right or catastrophically wrong. And that’s why we do it. Not because we’re seeking perfection, but because we’re seeking those moments of accidental brilliance when everything aligns and we create something extraordinary.

Or maybe we’re all just addicted to caffeine and overthinking everything. That’s also possible.

Just know this: the rewards totally make it all worth doing. Soldier on, Merlin!

Share you pain and your giddy highs in the comments. We’re all eager for your success. If you liked this (and there’s plenty more to come), and if you haven’t already, be sure to subscribe to The Coffee Authority Weekly. We’re just getting started, you and I.