As I read more and more on how CO 2 is released from freshly roasted coffee I decided to try my own experiment. Basically the experiment is to measure the captured CO 2 as it is released. A basic experimental approach is to use an eudiometer.

My setup is not quite as elegant.

The purpose of this test is to try the setup. The flask is 500 ml with 211 grams (~7.4 oz.) of medium roast Costa Rica coffee. The beans were loaded 5 minutes after dump with a temperature of 94oF. The graduated cylinder is 250ml and the tubing 1/4″ OD flexible copper. I am concerned that the inside diameter is large enough that air will escape up and water flow down. I will add a water dropper on the next version to keep water from going in and the air bubbling out. Also the tube should be shorter so that it is easier to get into the graduated cylinder.

Hours ml CO 2 1.4 20 3.7 29 11.7 76 13.0 80 19.0 100 22.0 112 24.0 122 24.6 124 26.0 129 36.0 152 37.0 154 46.5 172 48.0 176 49.5 180 59.5 194 61.0 200 71.0 214 84.0 224 94.5 236 104.3 246 108.0 250

The papers I found said the degassing would continue on whole beans for 7 days. Now that the output reached 250 ml, the capacity of the graduated cylinder, I am going to end this experiment and set up one comparing whole bean and ground coffee. To avoid the 250ml capacity I will put in 100 grams of coffee.