Home Roasting in a Wok


In the second installment of our series on how to roast coffee at home we are going to use a wok for roasting.  If you missed our first installment, you can find that here.  However you will find everything you need to get started in this article.  We'll have fresh roasted coffee in less than 20 minutes after we follow these directions.

Here are a list of the items we'll need in order to get started:

  • Wok
  • Stove Burner
  • Stirring Utensil, we used a bamboo spatula
  • Unroasted or Green Coffee Beans, we used our Colombia Timana Excelso
  • Mesh Sieve or Colander
  • Container for Roasted Coffee (about 2 cups in volume)

First, weigh out your green coffee beans.  For our test we used 120g or 4oz of coffee beans.  Now turn on your exhaust fan, and the stove.  In the wok, we found that a medium-high heat was about right to roast our coffee in about 8-12 minutes.  You can experiment with the heat, and the time to change the flavor of your coffee, but let's come back to that another time.  Add your unroasted coffee to the wok, and start stirring!  We want to stir vigorously, and keep the beans moving inside the pan as much as possible.  The thin layer of the wok, will conduct heat very quickly, and if we don't stir we will end up with beans that are burnt on one side, and raw on the other.  Stirring vigorously helps to ensure a more even roast.

 

A few minutes of stirring and you'll begin to see the coffee beans changing color.  They will go from green, to a pale yellowish color, a sure sign that we're beginning to cook or roast the coffee.  Keep stirring throughout the process so that the green coffee beans roast evenly on all sides. The wok's tall sides really help in this aspect because we can stir more quickly without worrying that the beans will spill out.

 

Soon the coffee will start to brown, this means we almost have roasted coffee!  You may notice steam and chaff, a papery substance starting to release from the beans, don't worry this normal.  Pretty soon, the beans will start to make an audible noise similar to popcorn.  This is what we call first crack, the water vapor has been evaporating inside the coffee, and now has built enough pressure to crack the cells inside the bean and escape.

 

You've successfully reached 'light roast' zone.  From this point we can pretty much stop roasting at whatever point we like, just depending on how dark you like your coffee roasted.  Generally speaking the darker we roast, the more body our coffee will have, while a lighter roast will exhibit more acidity.  For our roast, we turned down the burner just a bit so we could slow down our roast, and control the end point a little more precisely.

 

Once you reach the desired color transfer the coffee to your sieve, and cool.  Usually it is best to wait about 24 hours before brewing your coffee to allow some of the carbon dioxide to escape.  We brewed our coffee this morning, and found a great balance of vibrance and also of malty roast character in our cup.  Using a relatively fast roast time, with a darker outside color gives more complexity as you have different levels of roast from the outside to the inside of the bean.

Happy roasting!  We'd love to hear if you have questions, or ideas for the blog.