Choosing a home coffee roaster can seem daunting, but there’s one which – according to Harmony Coffee founder Ben Rowe – stands above the rest as an all-rounder which won’t break the bank.
Ben set up York coffee roaster, Harmony, a few years ago and began his roasting journey with the Aillio Bullet R1. Although Aillio has since introduced the slightly larger R2 model, the core principles remain the same.
Drawing from his experience, Ben has shared with us some valuable tips for achieving the perfect roast using the Aillio Bullet…
Where it all began
Ben first became interested in speciality coffee a few years ago, while living and working in Austria.
“I remember that was the first time I tried coffee that I really liked,” he says. “I’d never enjoyed it and had always associated coffee with something which was incredibly bitter and ashy. But when I tried one I liked, it opened up a whole world to me. Then when I came back to the UK, I couldn’t find anything that came close.”
Keen to discover more about the industry, Ben started chatting to some coffee experts around Winchester, where he was living and working at the time.
“I had some training in roasting through a contact I made and really it snowballed from there,” he says. “I eventually moved into the roasting world and then set up my own roastery.
“I’m lucky because I came off some really great experience. Before I started Harmony I was at Kiss The Hippo, and had incredible tutors there. It was like working with Michelin chefs!
“From there I just got talking to people, a lot of them over Instagram, exchanging ideas about roasting and I learnt very quickly how to do roasting properly and how not to make silly mistakes… how to craft a roast profile.”
Why the Aillio Bullet?
Ben says: “I actually owned the roaster which I started the company with before I decided I was going to launch a company. That was the Bullet.
“As far as I could tell, it was a popular roasting machine which was standing up in competitions. It made me realise that any problems weren’t down to the machine, it was all human error, so I had to learn everything I could about the machine quickly. And luckily, it’s very easy to use.”
Below, Ben shares his top tips from his experience roasting with the Aillio Bullet R1:
Measuring temperature
There are two probes on the Bullet. There’s the Infrared Bean Temperature Sensor (IBTS) and the regular bean temperature sensor. I would say, of the two, the infrared one is much more accurate.
If you’re going to make profiles, it’s the opposite of what you’d do with standard roasting where you’d use the bean temperature sensor. With this one, I’d always recommend basing your profiles off the Infrared sensor.
Importance of samples
If you’re roasting the same coffee more and more, maybe do three sample roasts to determine which of them you like best and then save that profile in your machine. You can use the recipe function to re-do that same roast, as it’s much more accurate than humans can be.
Use the software that’s built in – it’s there for a reason.
Drum speed
You can also change the drum speed. Usually you’d change it towards the end of a roast to reduce the bean contact with the base of the drum, maximising the amount of time that the beans are in the air rather than the drum wall.
I prefer to leave mine on 8 personally, because on 9 (maximum) I find the probes really don't work as well so I get much more variation in my readings. On 8, I don't really encounter any roast-related defects like scorching, and the beans still have lots of contact time with the air, allowing for convection based heat transfer, which is my personal preference.
Cleaning
I’d recommend cleaning this machine as often as you can, if not, you will run into all sorts of problems. Also, order spare chaff filters and a spare chaff box if you want to do lots of roasting. Seriously!
I’d say it’s best not to do more than 15 roasts in a day before letting the roaster cool completely.
Roast times, temperature and example profiles
Roast times can vary but I’d say anything between 8 minutes 30 and 11 minutes would be right, depending what you’re wanting to get out of it.
I’d say, when using the infrared sensor, the first crack would be somewhere between 198°C and 200°C. You can’t hear the first crack very well through the machine, as the blades are quite loud, so it’s easier to make a mark on the graph and use that as your reference point.
I’ve shared a few profiles which I’ve found have worked well for me, but it’s worth experimenting if you have the R2 as it may vary from the R1:
Good all-round filter-style roast: suggested parameters:
- 205°C - 209°C end temperature (using IBTS probe)
- 8:30 - 10:30 total roast time
- Spend 1:25 - 1:45 above 198°C developing the coffee
Light/Medium Espresso profile: suggested parameters:
- 209°C - 212°C end temperature (using IBTS probe)
- 10:30 - 11:30 total roast time
- Spend 1:50 - 2:20 above 198°C developing the coffee
Medium/Dark Espresso profile: suggested parameters:
- 212°C - 218°C end temperature (using IBTS probe)
- 11:30 - 12:30 total roast time
- Spend 2:20 - 3:15 above 198°C developing the coffee
Dark/Very Dark Profile: suggested parameters:
- 222°C - 235°C end temperature (using IBTS probe)
- 12:45 - 14:15 total roast time
- Spend 3:15 - 5:00 above 198°C developing the coffee
My own profile examples:
- Example of a lighter roast filter coffee profile (Al-Hayma, a Yemen Peaberry) 550g roast:
- A more medium roast, multipurpose profile (710g roast). This was a high density Guatemalan coffee - you can see that the coffee rate of rise graph reduces very quickly towards the end of the roast. That's where the coffee cracks open and colder steam escapes from the centre of the bean, cooling the local environment:
- An example of a medium-ish Espresso-style roast. (Brazil Natural 1kg). The Aillio has no trouble whatsoever keeping up with full 1kg capacity roasts, provided that you give it enough momentum at the start of the roast:
A final word from me:
I think for the price, and these are my genuine thoughts, it is the best roasting machine that you can get for the money with the same capacity. I don’t think there’s anything that comes close.
Of course there’s some that do different things, and it’s pointless to compare sample roasters. But for the price and home roasting like I do, there’s nothing that comes close.
Find out more about Harmony Coffee at: https://www.harmonycoffee.co.uk/