On the Grind

Blowing Hot Air – in the best way possible

Blowing Hot Air – in the best way possible

The Beauty of Hot Air

Have you ever lay on a bed of hot air? Sounds dreamy, especially around this time of year, right? While we mere humans may not have the luxury of doing so, each one of our coffee beans gets such a treatment before it leaves our doors.

As the general coffee enthusiast becomes ever more attuned to the source of their loved bean, there’s one part of the process that can sometimes be overlooked. After all the growing, picking, sorting, and drying is done, there’s the roasting!

This one can be pretty important. There’s no point in bringing some premium marbled Kobe steaks to the family BBQ if your uncle’s going to cook the poor things into oblivion on his old electric barbie that he thinks ‘does the trick’.

In essence there are two ways of roasting: drum and hot air. Do you know how your favourite coffee brand roasts their coffee? There are arguments for both and as always, a hundred different factors before and after the fact that will affect the quality in your cup.


At Underground, we use a Sivetz hot air roaster that has come all the way from Oregon. Michael Sivetz began manufacturing commercial hot air roasters in the 1970’s, after publishing one of the seminal works on coffee science - Coffee Processing Technology. The main feature and innovation of the hot air roaster is the ‘fluidized bed’ of air that the coffee circulates in. Sivetz’s theory behind this is that it creates a more even roast throughout each bean given the greater temperature control and even distribution of heat, which in turn brings a brighter, more complex taste out of the coffee.

And we would agree, the removal of the unwanted smokiness provides a clean, consistent taste, helping to bring out the most of the bean’s natural character and unique profile. 

The internet is awash with articles (and opinions) on the differing methods, to which we can safely say that one hasn’t proven to be superior to the other. Both have their place as a balance between tradition and innovation, art and science. That is the beauty of coffee. As above, the huge number of variables either side of the roasting all must come together flawlessly to give you that ultimate cup of Joe.

We think we do a pretty darn good job on that, but we’ll let you be the judge.

Hope you enjoy this month’s blend and if you haven't already grab your On the Grind box here.

From the team at Underground Coffee Roasters.

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