Saturday, November 17, 2018

Coffee Roasting #2

Hypotheses


Roasted coffee in a nonstick skillet for 15 minutes, color will be a 5 - 7 on the Sweet Maria's flavor profile scale.  There will be some unevenness in the roasting as indicated by lighter and darker beans.

Materials

  • Nonstick skillet for roasting.
  • Wooden spatula for stirring.
  • Fine mesh strainer to remove chaff.
  • Scale for weighing beans.
  • Glass bowl for weighing and storing final product.
  • Infrared thermometer to measure pan and bean temperature.
  • Timer for tracking roasting time.

Step 1:

Preparation for roasting.

Method:

Preheat skillet to 250 degrees Celsius using gas stove and infrared thermometer.
Measure 150 grams of green coffee beans into a container.
Have mesh strainer ready when beans come off heat.
Turn on exhaust fan over the stove.

Step 2:

Roasting

Method:

Start timer.
Pour all beans into skillet.
Stir with wooden spatula.
Stop roasting 15 minutes 46 seconds.
Remove from heat and put into mesh strainer.

Observations:

6 minutes into roasting heard first crack and continued to hear cracking.
10 minutes pan is at 240 degrees Celsius, beans are at 190 degrees Celsius.
12 minutes smokey enough had to turn the fan
15 minutes beans are 180° Celsius, pan is 230 degrees Celsius.  More smoke.

Step 3:

Remove chaff

Method:

Pour beans into fine mesh strainer.
Shake the strainer back and forth several times.
Pour into another container and pour back into the mesh strainer.
Repeat 10 times.

Observations

Chaff removed, roasted weight 126 grams.
Color fairly uniform and between 5 - 7 on the Sweet Maria's scale.


Reference



Fig. 1

Fig. 2

Fig. 1, 2. RAS, Sweet Maria's Postcard. Jan 21, 2015. Digital Image. Home Barista. Web. 17 Nov 2018. <https://www.home-barista.com/home-roasting/sweet-marias-roast-profile-summary-t34036.html>.

Friday, November 16, 2018

Coffee Roasting #1

I recently came into fifty pounds of green coffee beans and decided to try roasting some at home.  Here we go.

Coffee Roasting Experiment #1

Green coffee beans, origin unknown.
8" square cast iron pan.
Wooden spatula.
Multimeter with infrared thermometer.
Propane stove.
Timer.

Preheated the pan for several minutes on my stove's second to lowest setting.
Added green coffee beans.
Started timer.
Stirred constantly with wooden spatula.  Stirred using a back and forth, up and down pattern.  Tried to get the beans to flip over by pushing them up the sides of the pan.
Heard a crack at the 15 minute mark.
Temperature of the pan 250 degrees Celsius.
Took beans out of the pan at the 23 minute mark because they had a nice brown color.
Put into a small glass dish.
Temperature of the beans out of the pan was 150 degrees Celsius.
Left roasted beans uncovered at room temperature on the counter.
Weight of the beans post-roasting 11g.