The Effect of Different Sugars on Yeast

Sugar is the fuel yeast uses to expand.

Yeast is a living bacteria commonly used in baking that makes dough rise through the process of fermentation. For fermentation to occur yeast requires fuel in the form of sugar. The yeast reaction varies depending upon the type of sugar you use.

Effects of Kitchen Sugars

When mixing yeast with cane sugar, table sugar, and "equal" sugar substitute, the amount of carbon dioxide given off by the mixtures varies. Table sugar produces the most carbon dioxide followed by cane sugar. Because equal is not a true sugar it produces very little carbon dioxide.

Monosaccharides and Disaccharides

Monosaccharides like dextrose and fructose are single-ringed molecules. Disaccharides like sucrose, maltose, and lactose are formed when two monsaccharides join together. When mixed with yeast, maltose produces the biggest fermentation reaction causing the most carbon dioxide production followed by dextrose. Fructose and lactose each produce a very small reaction.

Considerations

You must have a liquid when mixing yeast and sugar together. The temperature of the liquid has a great effect on the amount of carbon dioxide that is produced. If the temperature is too low the yeast will not react with the sugar. If the temperature is too high the yeast bacteria will be destroyed.

References

• California State Univeristy: Effect of Different Isomers of Sugar on Yeast Respiration
• University of Colorado at Boulder: Respiration Rates by Yeast with Different Sugar Substrates and Temperatures
• Science and Plants for Schools: How Does Sugar Affect Yeast Growth?

Resources

• University of Regensburg: Fermentation and Sugar
• Stanford University: Saccharomyces Genome Database, What are Yeasts