Bread Lab: Jenna, Sheffield, Spencer

Blog Writer: Jenna

Photographer and documenter of evidence: Spencer

Chemist/Baker: Sheffield

Cellular Respiration  

The equation for cellular respiration is Glucose + oxygen  = water and CO2 + Oxygen.  Cellular respiration takes place in the mitochondria of the cells.  Cellular respiration is important in the bread making process so that bread can rise.  The reaction creates the products water and CO2.  The creation of CO2 during this reaction creates “bubbles” which is the reason for why there are holes in the bread. Wheat is a plant that is used in bread.  While the wheat was alive it went through photosynthesis, creating the products: glucose and water, from the reactants: sunlight, water, and CO2.  The bread needs the glucose from photosynthesis to go through cellular respiration to make CO2 and the bread rise.

Anaerobic Respiration vs Aerobic Respiration

Anaerobic respiration is cellular respiration where oxygen is not present.  Aerobic respiration is cellular respiration where oxygen is present.  With Anaerobic respiration, humans can undergo lactic acid fermentation while yeast goes through alcoholic fermentation.  Yeast is a single celled fungi that can go through alcoholic fermentation which causes the bread to rise.  This is important for bread making so that CO2 is released making the bread rise.

CO2 Cycle

Bread releases CO2 when exposed to heat. This CO2 is then converted back into oxygen through photosynthesis. This is how the process of making bread falls into the carbon cycle.  

Design rationale

We chose this recipe because of its simplicity.  This was our first time making bread so we wanted to do a recipe that wouldn’t be too difficult.  There are no special ingredients or methods for this recipe that make it too hard.

Recipe:

http://www.seriouseats.com/recipes/2010/05/bread-baking-the-simplest-white-bread-recipe-ever.html

Ingredients-

INGREDIENTS

• 1 tablespoon white sugar

• 2 1/2 teaspoons (1 package) yeast

• 1 cup lukewarm water

• 2 1/2 cups (11 1/4 oz) all purpose flour

• 1 teaspoon salt

• 2 tablespoons olive oil

DIRECTIONS

• 1. Add the sugar and yeast to the water in your measuring cup and stir to combine. If you're using anything except and instant yeast, let it sit for 5 to 10 minutes, or until the mixture is lively and bubbly. If it's instant yeast, you can continue without proofing, or let it proof to ease your mind that the yeast is alive—your choice.

• 2. Put the flour and salt into a medium bowl, and stir to distribute salt.

• 3. Add the water/yeast mixture to the the bowl with the flour, and stir to combine all the ingredients.

• 4. Sprinkle some flour on your countertop and dump the dough mixture onto the counter. Knead for a minute or two, adding flour as necessary to keep it from sticking. You don't need to knead until the dough is stretchy and elastic - just knead until it's a nice cohesive mixture and not a lumpy, sticky, blobby mess. Form it into a ball.

• 5. Drizzle the olive oil into a zip-top bag and plop the dough into the bag. Make sure the dough is completely coated with olive oil, zip the top, and stash it in the refrigerator overnight.

• 6. The next day, take the bag out of the fridge and massage it a bit, still in the bag, to mash out all the bubbles in the dough. You may need to open the bag to let the air out, but reseal it after.

• 7. Leave the bag on the countertop until the dough has come to room temperature, about an hour. It will rise and expand a bit during that time.

• 8. Preheat the oven to 350°F. Sprinkle some cornmeal on the bottom of a loaf pan.

• 9. Sprinkle some flour on your counter top, and dump the dough onto the counter. You don't need to squeeze every bit of olive oil out of the bag, but don't try to hold it back, either.

• 10. Knead and fold it a bit to incorporate the olive oil into the dough, then form the dough into a log that will fit into your loaf pan.

• 11. Put the loaf into the pan, cover the pan with plastic wrap, and let it rise until it has at least doubled in size. I used an 8 1/2-by-4 1/2 pan and let it rise until it was slightly higher than the pan.

• 12. Remove the plastic wrap, slash the top, and bake at 350 degrees for 35 to 40 minutes, until the bread is golden brown and the loaf sounds hollow when tapped.

• 13. Let it cool completely on a rack before slicing.

Recipe Reflection

Our recipe was successful, there wasn’t anything special about it but it was still good.  The only change we had to make to make the recipe work well was to add some flour so that the dough was not liquid.

Yeast-  The yeast is used to create CO2 and make the bread rise

Flour- provides the base for the bread. Flour contains proteins that when it is mixed with liquids, it creates gluten.  The gluten is a necessary part of bread because it is a rubbery substance that gives the dough structure and elasticity.

Sugar- the sugar is used as food for the yeast. Sugar is also used for taste if the dough has enough flour in it.  

Oil-  The oil is used to control texture and help with the taste.  Oil keeps the dough from being too elastic.

Salt- Salt tightens the gluten structure and adding strength to dough.  Salt slows down fermentation, allowing the bread to hold onto the CO2 produced.

Water- water is used for creating gluten.  The water also distributes heat while cooking.  The warm water at the beginning activates the yeast, starting the process of alcoholic fermentation