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Roast Lab With Candice Madison: A Deep-Dive into Roasting Science and Mechanics

Introducing Bellwether Roast Lab – a new platform for bringing together the best and brightest minds in the coffee industry to explore, experiment, and evolve the art of roasting using a Bellwether Roaster.
Our inaugural Roast Lab partnership features renowned roaster and coffee educator, Candice Madison. Known in the coffee industry for many, varied contributions, Candice is a roasting expert, SCA trainer, founder of Kandake Coffee, and so much more it’s hard to keep track.
We were lucky enough to sit down with them for our inaugural episode of Roast Lab. Watch to learn all about how Candice uses Bellwether’s industry‑leading thermal stability, consistency and control to create a new take on a classic coffee.
Candice also sat down with Chief Coffee Officer Arno Holschuh for a spirited webinar about the making of Candice’s custom roast profile.
In our conversation with Candice, we got into:
  • Why Peru is producing some of the best beans in the world
  • What it’s like working on the Bellwether Roaster
  • How to roast coffee using only your sense of smell
Prefer to read? Let’s get right to it.

How Candice Madison Thinks About Creating Roast Profiles

We asked Candice to pick a coffee, create a roast profile, and walk us through the entire process using a Bellwether Roaster. Here’s how it went.
(warning: inspiring roasting expertise ahead)

1. Select Your Green Coffee Beans (And Really Get To Know Them)

Candice began by selecting a Peruvian coffee from Churupampa that we sourced for the Bellwether Green Coffee Marketplace. The Tocto brothers are one of our favorite producer partners to work with because they’re working carefully to turn Churupampa into a model farm for both environmental sustainability and ethical economics by paying dignifying wages to their workers.
Candice explained that Peruvian farmers are now producing the types of coffee that they never thought they’d see in their lifetime. Too many people in the coffee industry are passing over Brazilian, Indonesian, and Peruvian beans, thinking that they lack complexity or are somehow “lesser coffees”. But farmers today are proving with dedication to their craft that there are some real jewels out there.
“I wanted to roast your Peru because I was always told, ‘oh Perus they’re great for blends, they’re just chocolate‑y, it’s fine’. But I was like, nah. It took me a while to realize that they were describing flavor profiles that they were able to execute—not what the coffee tasted like.”
Eager to disrupt old conventions and prove coffees from Peru can be exciting as single origins, Candice began to explain the first thing they always do when evaluating a new coffee: “Without fail, you’ve got to think about green coffee metrics: moisture, density, even the water activity. I want to know the process. How long was it sitting in port? All this information informs how you roast the coffee and what you can eke out of it.”

2. Tasting the Coffee and Identifying Your Goals

What are you looking to get out of your beans?
Candice, coming from a Scandinavian and British roasting background, prefers a roast profile that reveals the innate characteristics of the coffee, but with a lot more depth and development.
For these Peruvian beans, they realized the acidity in them was beautiful and something that they wanted to highlight. But they also wanted to encourage a sweet side to balance and contrast with the acidity present—while being very careful not to take it too far, which can, of course, ruin a roast.
“I really want some of this unctuous, syrupy sweetness to be cut a little bit with that acidity in a way that kettle corn is really satisfying because you can taste the sweet and salty together.”
With the end destination in mind, it was time for Candice to design a roast profile to get there.

3. Engineering the Roasting Profile

You know your beans and you know what you’re going for. Next up: how to actually achieve that while you’re roasting. Here’s how Candice does it.
1) Dehydration. The first stage of roasting is where the beans rapidly dehydrate, but it’s also where you have the most control over acidity and fruity notes.
Candice explained that, if you push your beans (not too aggressively) with heat before the yellowing phase and the Maillard Reaction, you can encourage molecules and compounds to degenerate fast, which creates notes of fruit and acidity. If you’re trying to avoid these notes, says Candice, proceed gently.
“To keep things simple, stage one is how much fruit and how much acidity do I want in this coffee, because that’s the only place where those chemical reactions happen. If I’m roasting for someone who doesn’t want a lot of acidity and isn’t into fruitiness, I’ll go gentler. For me personally, I go all out.”
Aroma: Floral notes, dried grass
2) The Maillard Reaction. The Maillard Reaction refers to the process of applying heat to food (in this case, coffee beans). This produces a cascade of reactions which in turn create the aromas and taste that we’re looking for in a coffee.
“A lot of people say this takes place between 305‑310 Fahrenheit, but every organic product has a different composition. So you don’t know that—you’ve got to use your sense of sight and smell to verify. Once the beans begin to turn yellow, you want to back off and let the flavors balance out with a nice, sweet note.”
It’s important to bear in mind the Maillard Reaction happens before you can see it. That’s why you need to rely on your experience, and sense of smell to predict this reaction.
If you push the bean hard during the dehydration phase, you have to let it float up here to get a balance of sweetness with fruity and acidic notes.
But if you push it too hard during Maillard? That’s where baking occurs (not during the dehydration stage as many people think).
Aroma: Baked bread
We asked: How can you tell if you’ve overbaked your roast after you’ve finished?
Candice explained that there are many ways to tell. “Baked coffee has flat acidity and is more towards the cardboard end of the tasting spectrum. There’s very little complexity at all. The best word to use? Meh.”
3) First Crack. This is the point at which the bean is almost edible.
“If you can’t control the first crack, then you’ve lost your roast. You can do all that good work beforehand and fail at the end,” said Candice. They went on to explain, “The trick is knowing your beans. If you know it isn’t going to explode from the heat (like our Peru) then you can be quite confident, reduce the gas, and let the bean develop as you want it.”
“But if you’re using a natural coffee (like a Brazilian, for example) if there’s too much heat in the bean you can turn the gas off right now. Let it release all its energy. Then you can turn it up when the heat has dissipated, wicked away all that moisture, and get to where you need to go. Control is key on this portion of the roast.”
First Crack Aroma: Sweet, roasted coffee smell. Sounds like popcorn, though some are very quiet indeed.
Second Crack Aroma: Similar smell as first crack but sounds like Rice Krispies.
Candice’s roast profile for Peru Churupampa is now available to all Bellwether Roaster users.

The Tension of Craft vs Automation in Roasting

Candice (and many of us at Bellwether!) started roasting before modern coffee technology made our lives a whole lot easier. They told us they were used to putting in the beans, seeing what happens, scribbling down notes on graph paper and making changes based on that.
It worked, but it did tend to waste bucketfuls of coffee. With the Bellwether Roaster, you can see the adjustments on a screen before you even put coffee in and have a better sense for what you’ll accomplish, resulting in less waste through trial and error.
Ultimately, Candice believes there really isn’t a tension between craft and automation for coffee brands that want to access the opportunity of quality roasting without the “ego” of traditional roasting processes: “The Bellwether unsettles the old‑school community because it takes the ego out of roasting. You don’t have to look fancy and smell things; it's done it all for you. It’s a fascinating machine and a great experience.”
We’re thrilled to bring consistent roasting to coffee companies who want to use automation and technology to skip much of the trial and error and get to quality coffee and profitability faster.

Sign Up For The Latest Roast Lab Videos

Thanks for reading this summary of the first episode of our new series, Roast Lab. If you enjoyed learning from Candice, then be sure to subscribe—we’ve got some of the biggest names in coffee roasting booked in for future episodes.
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