Meet Karlo, the founder of Four Wheel Coffee Roasters, one of our superstar ambassadors. He has been helping spread Firescope in his community, sharing valuable feedback for us to keep improving.

Can you tell us a little bit about your roasting? Which roasting machine you are using, your roasting style, and how much you produce?

Sure, so I'm using Coffed, the coffee machine that's been produced in Poland by people who used to be the official distributors for the Probat machines, then decided to make their own. What they did was, they disassembled one of the Probats and they basically rebuilt a new one for themselves.

Great, and how much are you producing every year? And who do you distribute your coffee to?

I roast about 10 tons per year. It's mostly for home use and companies, plus a few coffee shops around Zagreb and Croatia.

Do you roast differently for different customers or extraction methods?

The roast style? Well, I don't like to make the distinction between the espresso and filter roasts, because I think if you roast the coffee properly, you should taste the same notes both in espresso and filter.

I think what it depends on is the age of green coffee. The older the green coffee is, the more suitable it is for espresso. If the age of green coffee is really young, it fits both for filter and espresso.

In Croatia, we drink more espresso or espresso based coffees.

Can you tell us about how your roasting process was like before using Firescope?

Before using Firescope, I used to roast on a smaller machine called Aillio Bullet R1. It's a one kilo machine. It uses electric heat transfer, not natural gas. They had their own roasting software, but I didn't want to start using it right away. In the beginning I just wanted to train my smell senses so that I’d be experienced enough when I made the transition to software.

After I switched to a bigger machine, I started using Cropster. Back in those days it was expensive for me because I was just starting my business and paying around €70 per month was a bit too much. So I decided to switch to Artisan. But as you may already know, I was lacking the quality control and green coffee inventory features. I didn't have the ability to compare the roast profiles for that day or from the past five days.

When was your “aha” moment when using Firescope for the first time? What made you start using it?

I came across Firescope when Lea came to visit Zagreb. I used Firescope to roast beans for a few batches to start off. Within the first five to ten roast, both customers and I noticed the improvement of coffee, I'd say by at least 20-30%.

My favorite feature is the profile comparison, because it allows me to see how consistent my profiles are. That's important in roasting, in making coffee, making espresso, making filter coffee. There's no point in making five different roasts. The point is to make five identical roast profiles, the same espresso, the same filters. It's important to repeat the same action again and again. Previously, when I was using Artisan, I often didn't know what I roasted because they were lacking so many features. No roast profile comparison, no live data tracking, no green coffee storage. So basically I had one or two profiles in the background and basically I had to adjust for every coffee and then pray to God for the coffee to turn out well

So do you use the same roast style for every bean?

No, I don't have the same roast style for every bean. When I get new beans, I usually roast five to ten batches on my sample roaster. Then I see how the coffee is doing - should I use more or less heat? More airflow?

Then I have my own formula for how I should switch from the simple roaster back to the big machine. It's like cooking food. You don't cook the food same way.

So your coffee has become more consistent since using Firescope?

Yes, most definitely it's more consistent. I don't have such big differences in the roasts, but coffees are more sharpened, let's say. The story of the coffee is clearer. It's more like storytelling. From week to week you have the same coffee telling the same story, and that's the most important thing, to be as consistent as we can.

What would you tell other roasters who are hesitant about adopting digital tools?

Don't hesitate at all. Don't be afraid to try something new even for a month or two. You won't lose that much if you pay like $20, $30, or $50. You won't lose that feeling of crafting something with your hands. When you add a digital tool, you’ll know exactly what you are doing. It’s like comparing it to racing. You get that racing line which you can follow to get the same result over and over again, improving your quality of coffee beans or beverages in your shop or your roastery.

There's one funny story from the World Barista Championship 2023 or 2024. The PuqPress automatic temper was one of the official sponsors for the WBC, and the only competitor who didn't use the PuqPress won the competition. When they asked him why he didn't use it, he said, “well, the machine can give you consistency, but the machine doesn’t have feeling.” So basically, with your feeling, you can sometimes do better than machines. But as an experienced barista or roaster, when you develop that feeling and add digital tools, there's nothing that can stop you.

Karlo's straightforward approach reminds us that good tools simply make good roasters better— consistent results. His before-and-after experience with Firescope cuts through the noise about digital roasting: better coffee with less guesswork is what matters to both the roaster and their customers.

Want to try it out yourself? Get started for free here: https://eng.firescope.io/