Roasting Coffee at Home

Green (unroasted) Costa coffee beans from TranscendDid you know that for much of modern history domestic consumption of coffee involved roasting the beans yourself every time you intended to brew a cup of joe?

When coffee first swept Europe in the seventeenth century, most coffee was brewed and consumed in public coffee houses, but by the nineteenth century, most coffee was prepared at home.[1]  Green coffee beans were purchased from a grocer, then roasted, ground, and boiled just before serving.  And not just on lazy Saturday mornings: under every circumstance, if there was time to drink coffee, there was time to roast the beans yourself.  During the American civil war, green coffee was a standard ration for the Union army,[2] and every night soldiers would crouch over a fire to roast the beans.  (The same would have been true of the Confederate army if the Yankees hadn’t blockaded New Orleans so effectively, thus keeping coffee from the American south.)

It wasn’t until the 1840s that pre-roasted, pre-ground coffee was marketed.[3]  Before this, everyone knew that coffee tasted best when roasted just before brewing, but manufacturers started an ad campaign to convince Americans, especially housewives, that they in fact couldn’t roast coffee properly at home.

Obviously there are pros and cons to having the coffee roasted in advance.  Professional roasters have much, much more control over the roasting process.  They can manipulate temperatures very precisely, and they roast in rotating drums that brown the beans evenly.  And of course there is the convenience of not having to fire up the oven every time you want a cup of coffee.  These are the thoughts that discouraged me from roasting at home for some time.

Last summer I worked for the Nomad food truck.  I was cooking in their prep kitchen, which is located in a hilariously labyrinthine complex that houses a number of artists and businesses, including an Ethiopian coffee joint.  One afternoon we took a break from cooking and sat down for the traditional Ethiopian coffee ritual.  First incense is burned.  Green coffee beans are roasted in a bulbous container than resembles a large Florence flask (you remember those from junior high science class, don’t you?)  Then hot water is poured into the jug, and a feather is wedged into the slender neck.  The feather filters the coffee and prevents ground beans from falling into the drink.  Little cups are arranged into an array so they are all rim to rim.  Then the hostess pours the coffee in a slender but continuous trickle from a foot above the table, moving from cup to cup without breaking the stream.  Then you drink the coffee while munching on popcorn, of all things.  The coffee was good, but not great.  It was a fun experience, and at the very least it convinced me that palatable coffee could be roasted without the use of fancy equipment.

I asked Josh at Transcend to score me some of their green Costa beans, prized for their acidity.  He referred to my order as “a pound of green,” which made the transaction sound more illicit than it really was.

Let me say that I know a handful of professional coffee roasters.  I realize that roasting is a craft that one can spend years, indeed a lifetime, trying to perfect.  I realize there is a science to it.  There is expensive machinery.  I also realized that I don’t know anything about how to roast coffee, and I purposefully avoided researching how to do it well.

I spread some of my green beans on a sheet pan and put them in a 425°F oven and watched and waited and sniffed the air and periodically redistributed the beans on the tray.  Within three minutes there was a whiff of chocolate in the air.  And butter.  Actually it smelled like I was baking a chocolate cake, and the edges of that cake were starting to become slightly crisp and tacky and sweet.

Later caramel aromas showed up.  I started hearing the odd “pop” in the oven.  I pulled the beans when they were amber, much lighter than the lustrous black beans that I typically buy.

Lightly roasted beans v. green beans

I ground the coffee immediately, while still hot.  The powder had an orange tinge.

I brewed in a drip-filter coffee machine.  The final drink was noticeably lighter than most coffee I brew, with an orange hue that I associate with tea.  The aromas were more towards the fruit and nut end of the spectrum.  On the tongue, the coffee had a pleasant, mild acidity and a lingering, light chocolatey finish.  It was a good brew.

Will I brew like this every day?  No.  But if you are of the opinion, as I am, that coffee smells better while being ground than it tastes in the cup, this is the process for you.  It really did fill the house with a bewitching aroma.   Between the amazing scent of the roast, and the pageantry, I daresay the ritual of the brewing and drinking, I can say this is something I will definitely do again.  Next time with some friends.

A cup of home-roasted coffee



1.  Pendergrast, Mark.  Uncommon Grounds: The History of Coffee and How it Transformed our World.  Rev. Ed.  ©2010 Mark Pendergrast.  Published by Basic Books.  Page 44.

2.  Ibid.  Page 47.

3.  Ibid.  Page 46.  One of many, many memorable coffee ad campaigns explored in Uncommon Grounds.