Chocolate Yeast Bread
Baking Team:
Head Baker - Jess M
Photographer - Adam T
Blog Writer - Ethan K
Science
Cellular Respiration
Preparing for the experiment: Balloon lab
In order to begin to understand the process of how yeast interacts with different amounts of sugar we completed a alcohol fermentation lab. To set up the lab we added different amounts of sugar to each test tube, it was as follows:
BREAD BLOG
RecipeFirst we added ¼ cup of flour
We also added a bit of flour to the dough as we were kneading it to make it not stick to our hands as much and so the dough would stick together better
We then added 4 tablespoons of heated water
We also added ¼ teaspoon of yeast
Then we added ½ teaspoon of sugar
We also added ⅛ teaspoon of salt
Cellular Respiration
O2 + C6H12O6 -> CO2 + ATP + H2O
Happens in the Mitochondria
This makes CO2 which makes the bread rise
The wheat is doing photosynthesis then that glucose goes into the the mitochondria where it does cellular respiration
Anaerobic Respiration vs Aerobic Respiration
Yeast does alcoholic fermentation which is a form of anaerobic respiration and humans do both in Lactic acid fermentation and also does aerobic respiration.
My twist on this was to use Rosie, my yeast water culture, for approximately 50% of the liquid. Saturday morning refreshed some of my starter and left it to do its thing all day. Saturday evening I fed it again and left it overnight. At the same time I mixed up 50 g flour and 50 g yeast water and left overnight. Late the next morning I added the rest of the liquid to the YW preferrment and the flour and autolysed for 45 minutes. Added levain and salt. I only managed 3 sets of slap and fold / stretch and folds before it had doubled.
Bread Making Blog
To make sure the bread making process is a success, cellular respiration needs to occur. Cellular respiration is important because it creates CO2 for the bread to rise. This process occurs within the mitochondria.
The first time we tried our bread recipe we added the ½ teaspoon of sugar to the basic recipe we were given, because we found the yeast needs sugar to work. The yeast uses the sugar to perform alcoholic fermentation, a form of anaerobic respiration. From this process, the yeast releases carbon dioxide which makes bubbles of air, and causes the bread to rise. This is important for fluffy bread. We added this in the first step when we combined the dry ingredients which were ¼ cup of flour, ½ teaspoon of sugar, ¼ teaspoon of yeast and a pinch of salt.
