What air roasting is, and why we roast this way

Air roasting means the beans roast while floating on a stream of hot air, instead of tumbling against the hot steel of a drum. That air does two jobs at once. It heats every bean evenly from all sides, and it blows away the chaff, the papery skin that falls off coffee as it roasts, before it has a chance to burn.

That second job is most of the reason our coffee isn't bitter. It's also why we built Kribi around a kind of roaster most coffee shops never use.

How most coffee gets roasted

Chances are the coffee you drink every morning came out of a drum roaster: a big rotating barrel sitting over a gas flame. The beans tumble against the hot metal and pick up heat through contact, the same way a steak picks up heat from a pan.

It works. Plenty of good coffee comes out of drums. But the beans touching the walls run hotter than the ones in the middle of the pile, and whatever comes off the beans during the roast stays in the barrel with them. Keep that second part in mind.

How ours works

In an air roaster, hot air blows up through the bottom of a chamber hard enough to lift the beans off the floor. They float and churn in that column of air like popcorn in a hot air popper, which is a pretty accurate picture of what's happening. Nothing rests against a hot surface, so every bean gets the same heat on every side. People in the trade call it fluid bed roasting.

Our roasters have a clear chamber, so you can watch the whole thing: green beans go in pale and heavy, start dancing as the air picks them up, and slowly turn tan, then brown. They also run on electricity, not gas.

Why the chaff matters

Every green coffee bean carries a thin, silvery skin. As the bean heats up and expands, that skin dries out and flakes off. Roasters call it chaff.

In a drum, chaff can hang around in the barrel, scorch, and throw off smoke that settles right back onto the beans. A lot of the harsh, ashy taste people call "bitter" starts there.

In an air roaster, the same stream of air that's roasting the beans carries the chaff straight up and out into a collector the second it comes loose. It never sits in the heat long enough to burn.

Open the collector after a few batches and it's a pile of light, papery flakes, so weightless they drift off if you breathe on them. In a drum, some of that would still be in the barrel, scorching next to your coffee.

What you actually taste

Take the burnt chaff out and what's left is the coffee itself, which means you taste more of where it grew. Our Mount Oku comes from the volcanic slopes of Mount Oku in Cameroon, and in the cup it's caramel and red cherry with a little floral lift at the end. Those notes are easy to lose under smoke. Air roasting leaves them where you can find them.

Here's our opinion, after years of doing it this way: a lot of people who say they don't like black coffee have only ever had coffee that tasted like a campfire. Give them a cup without the char and they drink it black.

Air roasted doesn't mean weak, either. A dark roast still tastes dark. It just doesn't taste burnt.

Where we roast

At both of our cafes, Oak Park and Forest Park, the roaster sits right in the shop and we roast in small batches. Pick any coffee on the shelf and we'll roast a bag of it to order for you.

Bags you order on the website are roasted at our roastery in Chicago and shipped from there, so they're just as fresh when they land at your door.

Taste it for yourself

Reading about it only gets you so far. Brew a bag of Mount Oku the way you always make coffee, pour a cup of whatever you usually drink next to it, and taste them back to back. Or stop by either cafe and ask to watch a batch go. It's more fun to watch than you'd think.

Want the longer version? Our air roasting page has more on how the process works.