If you want to use a Vernier CO2 Gas Sensor and a Vernier ethanol sensor to show that CO2 gas and Ethanol are both produced during fermentation, you should use the following protocol. Please note that you will need a BioChamber 2000, order code BC-2000, $22, and a Stir Station, order code STIR, $129 with a magnetic stir bar.
1. Prepare and setup the Ethanol Sensor as described in the sensor booklet.
2. If your CO2 sensor has a switch, set it to the High (0-100,000 ppm) setting.
3. Connect the sensors to the data-collection software.
4. Place a BioChamber 2000 mL container on a stir station. Place a magnetic stir bar in the chamber. Add 250 mL of warm water to the chamber and turn on the stir station. Make sure the stir bar is spinning at a medium speed.
5. Add 30 g of table sugar to the water in the chamber and allow it to dissolve.
6. Add one tablespoon of baker's yeast to the liquid in the chamber.
7. Using a gentle, twisting motion, place the Ethanol Sensor equipped with split stopper into one of the openings in the BioChamber. Important: Use a ring stand and a clamp or electrode support to secure the sensor. Adjust the sensor so that the tip of the sensor is one cm above the level of the liquid.
8. Using a gentle, twisting motion, place the CO2 Gas Sensor in the other opening in the BioChamber.
9. Begin data-collection.
10. Determine the rate of CO2 gas and Ethanol vapor production using the Linear Fit features in your data-collection software.