Yeast Experiment: Growth #1 – Sugar
and Yeast

QUESTION

HOW DOES SUGAR AFFECT THE GROWTH OF YEAST?

MATERIALS

• Two glass measuring cups, 1-cup capacity each
• Measuring spoon: teaspoon
• Granulated sugar
• Thermometer (to test water temperature)
• Warm water (110-115°F)
• Two packets of Red Star Active Dry Yeast (each packet is ¼-ounce or 2 ¼ teaspoons)
• Timer

PROCEDURE

1. Fill two 1-cup glass measuring cups with ½ cup each warm water (110-115°F).
2. In one cup, add 1 teaspoon granulated sugar; stir to dissolve. Add one packet yeast; stir for 30 seconds.
3. In other cup, add one packet yeast; stir for 30 seconds.
4. Set timer for 10 minutes.

OBSERVATIONS & CONCLUSION

1. Which cup had more yeast foam, and why?
2. Is sugar necessary to the growth of yeast, and why?
3. What other examples can you think of where sugar is important to the growth of yeast?