Home Coffee Roasting

Home coffee roasting is much easier than most people realize.  Roasting green coffee beans takes practice though and if done correctly, the results will be far superior to anything you would buy at your local store. The biggest advantage to home coffee roasting is that it allows the coffee lover to experience the freshest cup of coffee by roasting Arabica green coffee beans at any time to any roast style.  In addition, because of the vast selection of green coffee beans, the home coffee roaster also can create a coffee profile best suited to their own flavor preference.

Home coffee roasting is the gradual process of heating the green bean to a desired roast. Different degrees of roast can be obtained by monitoring the coffee roasting process.  How is it done? The green coffee bean goes through a chemical change that causes the bean to change color during the coffee roasting process.  For a better understanding of roast styles see our chart on roast styles.  Roasting green coffee beans can be done by several methods. The most economical method is roasting the green coffee beans in the oven (convection gas ovens producing a more even roast) or over the stove in a heavy frying pan. There are also several manufactures of home coffee roasting machines on the market today, which make the roasting process easy and more consistent. 

Whatever method you choose to try please keep in mind safety precautions when roasting coffee.  Roasting requires supervision.  Roasting at high temperatures require proper items to safeguard accidents- be prepared & organized, have items needed and handy.  Roasting coffee beans can emit smoke and chaff (a paper like skin that detaches from the bean in the roasting process). Roasting coffee to achieve a dark roast can produce oil called, caffinol, if left unmonitored can be flammable.  In other words, do not walk away from the roasting process or wait for the timer to alert you -you may have your oven, stove or coffee roaster up in flames and that would not be good.

For a better understanding on home roasting or coffee check out our book selections 0n the subjects

Oven Instructions

Items needed

Preheat oven to 475-525 (this will vary according to bean and amount used).  Place beans in pan – spread evenly, only one layer deep.  Place beans on the middle shelf in a hot oven.

Wait 8 - 10 minutes for the "first crack", although this noise sounds more like a pop. After the initial crack, you will notice a paper-like substance referred to as "chaff", shedding from the beans. This chaff will float away later as the beans cool after roasting. (Note: chaff is harmless but can make for a messy kitchen if not disposed of carefully.)  A few minutes after the first crack, start checking for the desired roast. See roasting chart for information. As beans darken, rotate the pan so that you will more evenly roast the beans. Soon they will begin to smoke, so it may be a good idea to turn on the exhaust fan at this point. If a darker roast is desired, a "second crack" will begin after a few more minutes.

Using oven mitts, remove roasted coffee from the oven and pour in a colander or wire sieve to cool.

Agitate the roasted beans to remove any chaff. In addition, blowing lightly will help to remove any remaining chaff and help cool the beans off faster. (Note: It is advisable to perform this outside of the house since it can make quite a mess indoors).

Seal cool roasted coffee in an airtight container out of direct light. Do not store in refrigerator or freezer for this affects the moisture content of the coffee bean.

Roasting Chart

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Pan Roasting

Items needed

Put enough coffee beans to cover the bottom of pan evenly at a thickness of one layer

Start at a medium to medium-high heat setting stirring beans regularly with a wooden spoon. Not stirring the beans regularly will result in an uneven roast. After approximately 7 - 8 minutes, you should hear the "first crack". After another 2 minutes, begin looking for your desired roast (see roasting chart). A second crack will be heard if left in for a darker roast. Note: Beans will continue to roast after removing from the heat, so it is critical to cool down as soon as possible.

Remove beans from pan and pour into a metal colander or sieve to cool. Agitating the beans by blowing and shaking the colander will remove any chaff remaining on the beans. (Note: It is advisable to perform this outside of the house since it can make quite a mess indoors). 

For a demonstration of this process check out http://www.aranzullo.com/brew/brew.html

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Hot Air Popcorn Poppers

Since most homeowners have these on hand, using air popcorn poppers has been a convenient method for roasting coffee beans for many years. 

The beans are poured into the chamber much like popcorn is and the beans begin to spin around, being stirred automatically by the fan in the machine. As the popper is heated, the beans begin to change color. After 8 minutes or so, you need to monitor closely...look, listen, and smell...much like roasting in an oven or on a stove to insure your desired roast.

Using a thermometer that registers to 550 degrees is helpful for monitoring a more consistent roast.

Caution: Hot air popcorn poppers are not made for coffee roasting even though many home coffee roasters use this method. When using high heats to roast coffee, one should use extreme caution with constant supervision to prevent fires and injury.

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Using Roasting Equipment

 Several manufacturers today are offering home roasting equipment.  Some home roasting machines can roast up to 1/2 lb. of green coffee, remove chaff, and cool the coffee in less than 10 minutes.  The roasting levels are completely adjustable which will give you more consistent results and a more flavorful roast. 

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