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Bread Blog- Brenna, Sydney, JP: 2nd Period

risingtotheoccasion's picture
risingtotheoccasion

Bread Blog- Brenna, Sydney, JP: 2nd Period

 

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:IMG_0741.JPG

 

Test tube #1- No sugar

Test tube #2- ½ tsp of sugar

Test tube #3- 1 tsp of sugar

Test tube #4- 2 tsp of sugar

 

After we finished adding all the different amounts of sugar to each test tube then we added 10 mL of 120 degree water to each of the tubes, it is very important that the water is at this temperature so that it is hot enough to activate the yeast, but not so hot that it kills the yeast. Following the addition of water we added ⅛ tsp of yeast to each tube and covered the opening of the tube with a balloon, after this we shook the tubes to dissolve the yeast. The balloon will help us measure the amount of carbon dioxide. Through this procedure we continued to measure two things; the amount of air in the balloon and the height of the carbon dioxide bubbles.IMG_0751.JPG

 

After 10 minutes- Test tube #2 had both the most air and the most carbon bubbles (2cm) and test tube #4 had the least bubbles and air (.5cm)

 



In the end of our experiment test tube #2 still had the most air and bubbles, now at 4cm and test tube #4 still had the least of both remaining at a height of .5cm and almost no air in the balloon.

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Day #2: Research

Before we could actually make our bread we needed to figure out a recipe that would give us optimal carbon dioxide production and rising of the bread. We did this by researching the different things in bread that help make it rise such as gluten. Through this research we were able to determine what ingredients we should add to our bread to increase how much it would rise. For our bread we decided to add sugar because as proven in the balloon lab adding a certain amount of sugar helps to increase carbon dioxide. We also decided to add olive oil because while we were researching we found that olive oil reacts with the gluten and helps to increase the rising properties of bread.

 

Day #3: Practice Round IMG_0805.JPG

The purpose of this day was to test out our recipe and discover any flaws it may have, so that we could adjust the recipe before the actual baking day. We started with the steps of the original dough recipe; we added the ¼ cup of flour and ¼ tsp of yeast to our plastic bag in addition to this we chose to add sugar (1 tsp)  and salt (a pinch for flavor).  





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After the completion of the dry ingredients we needed to heat our water to add. As mentioned before we needed to make sure the water was at an optimal temperature to activate our yeast (120-130 degrees). Once our water was properly heated we added 4 tablespoons of the hot water to our dry ingredients, we also chose to add olive oil to further activate our yeast (½ tsp), we then mixed all the ingredients in our bag.




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Kneading our bread proved to be a challenge; it was very sticky and we couldn't get it to come together even with the addition of extra flour. Our bread also didn’t rise as well as we had hoped. Through this first round we learned that we needed to add more flour to our bread to make it much less sticky and easier to knead. We also decided we were going to add more olive oil to hopefully increase the amount that our bread would rise.   




Day #4: Final Dough

Today was the final day and we needed to make sure that this time our bread would rise properly and that we would be able to kneed it this time without it being overly sticky, like our experimental bread the previous day. We made many changes to hopefully make this change occur, these included:

 

  • Adding ½ tablespoon of sugar instead of 1 teaspoon of sugar

  • We added another ½ teaspoon of olive oil with the remaining flour as well as still adding olive oil with the water

  • Instead of just adding  ¼ a cup of flour the second time around we also added just an additional ⅛ cup

  • Before we started kneading the bread we made sure to thoroughly cover the parchment paper in flour to reduce to sticking of the dough, we also added flour to to sydney’s hands and the dough

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This time when we added the dry ingredients, water, and oil to our bag and let it sit for 10 minutes there was much better carbon dioxide production than the previous day, we think this has to do with the addition of extra sugar to our dry ingredients. This is because the yeast feeds on the  sugar and this creates carbon dioxide so and increase in sugar makes for an increase in carbon.   


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We also made sure that when we were kneading our dough that we first covered the parchment paper in flour so it wouldn’t stick to the paper, and we continued to add flour until the dough was at a good consistency and we could roll it into a ball. The addition of the extra flour really helped reduce the amount of “stickiness”  in our dough and made it much easier to knead and eventually form a ball.



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We checked the progress of our bread rising every 5 minutes and each time we checked it the bread continued to rise. The first time we checked it the bread was at 2.5 cm and that was at 10 minutes, then at 15 minutes the bread had rose to 3.5 cm. For the last 15 minutes our bread remained at 5 cm. This proved that the changes we made the first day greatly improved the outcome of our bread and helped the production of carbon dioxide massively. IMG_0829.JPG



Day #5: Finished Bread!!

Our bread really rose to the occasion! With the changes, we made our bread rose a ton indicating lots of carbon dioxide production. When you looked at our bread from the outside it was a nice golden brown color on the top and it had clearly rose above the top of the muffin tin. We split our bread in half to see the inside of the bread and we saw a ton of bubbles and it was very light and airy. The taste of our bread was pretty bland and tasted like flour and yeast, we compromised the taste for increased carbon dioxide production and rising properties.IMG_0837.JPGIMG_0834.JPG

 

The reason our bread rose substantially and made so much carbon dioxide is because the second time around we added more flour to our dough. Once the yeast is activated it comes in contact with the flour and feeds on the sugars that are in it, this releases carbon dioxide. We also added more sugar which also gets broken down by the yeast and produces more carbon dioxide, all of this carbon dioxide made our bread rose.
















Breaking it down: The science of bread

The equation for cellular respiration is C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP. The process of cellular respiration occurs in the mitochondria. The mitochondria is the powerhouse of the cell; makes the energy. Cellular respiration is important for bread making because yeast is what goes through the process. Yeast goes through anaerobic fermentation which also helps produce beer and happens without the presence of oxygen, while aerobic respiration requires oxygen to be present. During the bread production, yeast starts to respire, creating carbon dioxide and water to help the bread rise. After the oxygen runs out, anaerobic respiration begins.










Plants are important to cellular respiration because they allow for the process of glycolysis which is the breakdown of glucose. This process occurs in the cytoplasm of plants, and when the glucose is broken down the yeast can feed on the sugars that come from it, and carbon dioxide is in turn produced. During this lab the wheat in the flour was the main peice responsible for this taking place.

 

Yeast and humans have more similar characteristics than opposing characteristics.

Yeast vs Humans: Yeast undergoes cellular respiration by starting with aerobic respiration. After the oxygen runs out, anaerobic respiration occurs and the alcohol is evaporated in the high temperatures in the oven. Humans: Humans undergo aerobic respiration because they breathe in oxygen and aerobic respiration is with oxygen. Humans also go through anaerobic respiration because humans go through lactic acid fermentation.










Bread making falls into the carbon cycle due to the fact that the yeast respires and released carbon dioxide into the atmosphere. In the environment, the yeast can be found in plants. The plants take in the carbon dioxide and goes through photosynthesis. This causes it to release oxygen and all living things take it in. Temperature is related to amount of CO2 produced by yeast, this being higher temperatures will result in more production of CO2 and the cycle keeps going.




















Comments

tptak's picture
tptak

I think you meant yeas could be found _on_, not in plants?

dabrownman's picture
dabrownman

of fructose -  that yeast can't even metabolize.  What happens is that amylase enzymes, also found in the flour ,act as catalysts when the flour is hydrated that help to break the protein bonds in the abundant starch that is in the flour which breaks the starch down ito sugars that the yeast can metabolize.

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