Scientists Clash in Coffee Roasting Competition [video]

How hard could roasting beans at home really be? Sam and George go head-to-head in a coffee roasting competition to find out, and Candy Schibli, the founder and head roaster of Southeastern Coffee Roastery, provides expert advice.

Video Transcript:

Here are the beans.

All right. So today we are attempting to roast coffee beans ourselves at home, in a frying pan using our chemistry knowledge.

And this is a throw down a challenge to see who can roast the better beans. Me…

…or me. It’s definitely me.

Okay. So to prepare for this challenge, I read a bunch of coffee, roasting blogs, and then really went down the YouTube rabbit hole. I think I have a plan to win.

I did absolutely no research for this. So I am going to just completely wing it and see what happens.

I’m really doing a terrible job. I’m already burning the outside of the beans.

Are these supposed to end up looking like normal coffee beans?


Hmm. I don’t think it’s working so much.

These are possibly the most unevenly roasted beans I have ever seen in my life.

This is what professionally roasted coffee looks like. Look how even that is. And then look at mine, professional mine.

So about 10 minutes on the grill, they were still greenish yellow. I bring them in here. I crank up the heat.

Yeah. These are really unevenly roasted.

Well, I am definitely not winning this challenge with these beans. So I’m going to try again.

Today I have maybe okay is my label on this one. And then this is my oopsie.

You taste yours first and then I’ll I’ll show, I’ll show you what I, okay.

This is not terrible.

Now taste tastes the oops one.

I’m so afraid to taste this.

It smells a little burnt.

Yeah. Like it really does not taste like coffee. To me. It has a terrible aftertaste. It’s really bad. It’s not pleasant.

I screwed it up from beginning to end. And this is my, this is my cup.


I don’t know if you can tell, but it’s a lot lighter than our stuff.

Yeah it looks pretty weak.

Okay. Let me taste it.

You know what? That’s not half bad.

If I didn’t know any better, I would be like, hh man, they brewed this wrong, but it doesn’t taste like I burnt it.

So we both made mediocre to straight up bad coffee, but it got us thinking.

Could we reach out to a professional coffee, roaster, someone who does this for a living and get some tips or tricks or something to make home roasting in a frying pan, actually work.

I decided to call up someone who actually knows what they’re doing and I’m doing this interview without George to make sure I win.

Candy Schibli is the founder of Southeastern Roastery where she is also the head roaster.

First of all, let me commend you on your exploration. I love it.

That’s like a really nice way of saying like here’s a participation trophy.

Was there anything when you started roasting, maybe it was during the process itself that you were so surprised by?

Probably what surprised me most, the actual sound there’s a sound component and a smell component that goes along with coffee roasting, they’re really distinct cracks and coffee that indicate a point in the roasting process.

And like at what point those cracks happen and how frequent they are, how abundant they are. They like roll slowly. If they’re like really, really popping, you know.

That’s the thing about coffee roasting that I found so interesting is that there’s a very fine line between something tasting really good and then taking it too far and having it be really gross.

It’s generally a few seconds.

Yeah. That’s so much pressure.

There’s so much that could go wrong so quickly because of all the stuff that’s in a coffee bean. So what is that stuff?

They’re mostly made up of carbohydrates like cellulose and soluble carbs, like sucrose and glucose. They’re also made up of lipids, proteins and the amino acids that make up proteins.

All of these components are affected during roasting and are important for the smells and tastes that you associate with coffee.

And maybe you’ve heard about the possible health benefits of coffee that have to do with antioxidants.

Well, the antioxidant chlorogenic acid, it makes up about 10% of the bean caffeine, which I would personally say is coffee’s number one attribute makes them about 2%.

And I had no idea before I started researching this. But caffeine content is actually not all that effected by roasting when coffee beans are roasted, it’s a super dynamic process, lots of chemical reactions, but we’re a range of temperatures.

Here’s a really simplified version of that.

If you’re roasting beans on a cast iron skillet, get it to about 200 degrees Celsius, then throw the beans in.

When you drop the beans into the skillet, they start absorbing heat. The beans start to turn a yellowy golden as compounds like chlorophyll start decomposing.

It kind of smells like you’re popping popcorn or burning toast.

The temperature of the beans builds at a hundred degrees Celsius. The water in the beans will start to vaporize pressure from that water vapor or steam builds up enough to cause the first crack.

Nearing 200 degrees Celsius, the temperature of the beans continues to rise and sugars, proteins, and lipids begin to decompose.

This is a process called pyrolysis and it leads to the creation of some of the fruity citrusy flavors we associate with coffee. As well as melanoidins, which give the beans their color.

At this point, a bunch of different gases like carbon dioxide are building up in the bean. Those cellulose walls can’t contain the pressure. So they crack.

That’s the second crack. A bunch of aromatic compounds are also released during the second crack.

The bean is now medium to dark brown in color and has an oily sheen from the lipids that can now reach it the surface since the cell wall is ruptured.

All right, first things first. If you’re roasting coffee at home in a frying pan, it’s going to be really hard if not impossible, to get evenly roasted amazing coffee beans.

But if you have no other choice, here’s Candy’s advice.

Having a cast iron skillet, I think is a, is a good idea as particularly because it’s a very like even heat. You know, you want to start the grill at about 400 and that includes the pan itself.

You can check the temperature of the grill itself, but you can’t check the temperature of the beans. And then that’s something that really impacts how you roast. So you’re just going to have to guesstimate on that.

You know, making sure that the beans are constantly shaken or rotated around, uh, for a good, I would say 10 to 12 minutes, we’ll get you a generally a light roast.

Even with you shaking the pan. They’re not going to be super even.

I’m like excited to like, to really just dive in and start roasting.

I want, I want to taste them. You got to roast and like send some to me.

I don’t know though. I’ll be really embarrassed cause you’ll be like, Mmm, these are still really bad.

Time for take two. What I’m going to do differently this time is roast the beans on a much lower heat setting. And hopefully that’ll take a longer period of time.

Let’s see how this goes.

I’m not sure how much better this is.
I’m really excited to do this.
George. You want to go first?

Here is attempt number two … in success mug.

Honestly, it does not smell any better than the first time.


Here’s the thing I personally don’t like it, but this tastes more like coffee than the first time I did it.

So you think you could get away with selling this to humans?

I could sell this to a hipster for $8. Yes, absolutely.

I’m pretty proud of myself. So I chatted with Candy Schibli and she gave me a lot of great tips. One of the best tips that she gave me was do not have your pan at, at an insanely high temperature.

It was actually pretty successful I think. The beans are pretty even let’s see.
They’re pretty even brown. Oh, there we go. So not too bad.

Moment of truth. This is legitimately good. Actually. I’m so proud of myself for taking Candy’s advice.

I was going to say we can thank Candy for this.

I followed directions and I’m really happy about that.

That’s my win.

So cheers.


Cheers, Sam.

6 Comments on "Scientists Clash in Coffee Roasting Competition [video]"

  1. My dog bowl / heat gun roast was VERY non-uniform. Yet is was DELICIOUS. Uniformity doesn’t necessarily mean best flavor.

  2. Stopped at a “garage” restaurant in Cuba. Cooked in their house and served in the garage. Brother-in-law orders coffee and started talking to them in the kitchen. He tells me to go come over. They are roasting the beans in a pan. Ended up ordering coffee and it was one of the best I’ve had. Nothing like having a fresh roast.

  3. The green beans you showed in your video are from Sweet Maria’s home roasting coffee company in Oakland, CA. On their website are some of the best tutorials if you want to try your hand at roasting coffee. There are many ways to get started roasting coffee at home. One of the tried and true methods is to use a hot air popcorn popper which is a method referred to as fluid bed roasting. You can get a fairly even roast on a handful of beans easily with this method. Hint: Research a little bit about how far to roast the beans based on their origin and your taste preferences before you start roasting.

  4. Coraline Jones | August 9, 2020 at 2:54 pm | Reply

    What the heck did I just read? It sounded like a conversation between two 12-year-olds.

  5. Like good wine, good coffee needs good grapes, good coffee needs good coffee beans. Roasting is secondary,and won’t turn bad beans into good coffee.

  6. Use air popcorn fryer machine, i made amazing roasting daily with it.

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