Welcome to Chemistry Connections, my name is Maggie Maclean and Lilla Antal and I am your host for episode 12 called Chemistry of Bread. Today I/we will be discussing the chemistry involved in the making of bread.

The first bread was made around 12,000 years ago and was created by coarsely crushed grain mixed with water, with the resulting dough probably laid on heated stones and baked by covering it with hot ashes. At the time, we can imagine it was the tastiest bread out there. However, there is such a wide variety of different types of bread now. Whether it's sourdough, bagels, croissants, whole grain, Irish soda bread, English muffins, biscuits, pumpernickel, banana bread, or pizza dough it is found in all parts of life. Even people intolerant to these ingredients can enjoy a substitute made with gluten-free dough.

• Maggie: My personal favorite is the classic Irish soda bread with gluten-free wheat of course toasted with raspberry jam and butter. This is the bread my parents made me growing up to connect me to my heritage.
• Lilla: You know I like a good whole grain rye bread toasted with eggs and cheese.
• Unison: Comment down below what YOUR favorite bread is, and while you’re down there smash that like button!!!

Getting back on track… By the late nineteenth century, enzymes in the form of malt were being added to flour and dough to control and aid the breadmaking process in emerging commercial bakeries. However, over time this practice was abandoned as new chemical additives and processing aids became available. Let’s pause here and look at some of the chemistry at work.

Lilla: The yeast in bread contains enzymes that can break down the starch in the flour into sugars. Yeast produces the enzyme maltase to break maltose into glucose molecules that it can ferment once the starch has been broken down into these simple sugars, other enzymes in yeast act upon simple sugars to produce alcohol and carbon dioxide in the bread-making step called fermentation.

Maggie: The enzymes in yeast are natural catalysts. A catalyst is a substance that speeds up a chemical reaction or lowers the temperature or pressure needed to start one, without itself being consumed during the reaction, in bread making the catalysts accelerate the fermentation of bread. Fermentation is the process where the dough produces and retains carbon dioxide in the form of microscopic air pockets. It rises as a result of this. Catalysts break down complex carbohydrates into sugar which yeast can feed off of. With sugars fueling yeast, it releases CO2 which makes bread rise. An you know I like a fluffy bread.

Lilla: When reactions happen, there energy is needed to break the...