Pretzels By: Nicole, Alex, and Cross

Roles:

Alex-Blogger

Nicole- Chemist/Baker

Cross- Photographer

Recipe:

Makes three large pretzels

1/2 teaspoon instant yeast

1/2 tablespoon malt powder or brown sugar

1 1/4 cups all-purpose unbleached or bread flour

1/2 teaspoon salt

½ teaspoon oil

1/2 cup warm milk (approximately 110 degrees, which is 1 minute in my microwave)

Procedure:

1. Mix yeast, flour, and warm milk together.

2. Let those ingredients sit for ten minutes.

3. Add in the sugar, oil, and salt.

4. Once all ingredients are added together mix the ingredients until it forms a soft dough.

5. Once soft dough is formed knead the tough for  2-3 minutes.

6. Once dough forms into a solid mass form long strands of dough and shape it into a pretzel.

Cellular Respiration:

Cellular respiration is happening all around us, even while making bread.  Cellular respiration is in both, anaerobic and aerobic form, while baking bread.  For cellular respiration to take place in the mitochondria their needs to be access to glucose and oxygen. This glucose and oxygen then forms into CO2, Water, and 38 ATP! This is also why we see bubbles in our bread, because the CO2 is created while cellular respiration occurs. Essentially this is what is happening in the mitochondria of the bread to create energy for us to consume:

This process is important while bread making because the yeast carry out cellular respiration making the bread grow or rise. The yeast makes the bread grow by exerting CO2 and energy into the bread. Wheat which is a plant plays a very important role while making bread. When the wheat is mixed in with bread before baking it adds a certain strength and elasticity. It gets this from by holding on to gases from the fermentation allowing the bread to rise.

Anaerobic Respiration vs Aerobic Respiration:

Yeast V. Humans:

Anaerobic respiration and aerobic respiration don't just happen in our bodies but in bread as well. Yeast starts off anaerobically with alcoholic fermentation helping  the dough rise. This process creates much less energy. Yeast can also perform aerobic respiration when exposed to oxygen. Humans are the same way “they can perform both aerobic and anaerobic respiration.” However, the difference occurs when humans start lactic acid fermentation. Humans use a different form on anaerobic respiration, this is seen in lactic acid fermentation.

How is this important in bread making?

The differences in respiration play a key role in bread making. Aerobic respiration helps cellular respiration occur in the bread; this gives the bread energy. Anaerobic respiration is used in alcoholic fermentation within the yeast of the bread.  This is important because alcoholic fermentation creates the product of CO2 helping the bread rise.

CO2 Cycle:

The CO2 cycle happens everyday, but it is also happening when we make bread. Bread making falls into the carbon cycle by releasing carbon dioxide into the atmosphere. This carbon is released in both processes of alcoholic fermentation and in cellular respiration. This is because in both processes carbon dioxide is a product. In the environment yeast can be found in many fruits, berries, and plant exudates. In nature yeast perform the same operations as they do in bread, releasing carbon dioxide into the environment.

Design Rationale for Recipe:

• Yeast:

Yeasts are eukaryotic, single-celled microorganisms that can sometimes be classified as a fungus. Yeast needs warm liquid at the temperature of 120-130 degrees fahrenheit, some sort of sugar substrate, and oxygen to perform alcohol fermentation. Yeast is added to bread dough for the purpose of getting the bread dough to rise to make the texture of the bread more luxurious and fluffy. However, when you use yeast you need to verify the water you are using is warm because the yeast can only grow in specific conditions. If the water is less than 120 degrees fahrenheit the yeast will not activate and this causes the bread to not rise, but if the water is over 130 degrees fahrenheit then the yeast will die because it is to hot.  

• Flour:

Flour is a powder used to make many different foods. Flour is made by grinding raw grains and roots. When the gluten in flour is combined with water it causes the gluten to form protein. This protein/gluten allows bread to form and take shape.  Also, gluten swells to form many continuous fine strands when the flour is mixed with water. These strands also form the structure of bread dough as well as making the bread more elastic.

• Sweeteners:

We have brown sugar in our dough recipe as a sweetener. We add this brown sugar to our dough because it helps speed up the activation of the yeast. Instead of just giving the yeast flour to feast on the direct sugar can help the yeast start up and consume quick energy to get working. Usually only small amounts of sugar is needed in bread, for example our recipe calls for only ½  tablespoon. Although one should never use artificial sweeteners while making bread. Artificial sweeteners do not perform the same functions natural sugar does because artificial sweeteners don't provide food to the yeast.  

• Fats:

Fats can be anything from butter to margarine to oil. In this recipe we use oil in making the bread. This oil is used because  it enriches the dough's texture, flavor, freshness, keeping properties, and it helps moderate gluten and protein development. In recipes fats usually come in small amounts, around 1-2 tablespoons. Bread recipes also sometimes add salt, like this recipe. In this recipe ½ teaspoons of salt are added and this is a pretty regular amount. Salt is added in bread for flavor and to add strength to your dough. Salt adds strength to your dough because it tightens the gluten structure in your bread. Salt helps the loaf hold the carbon dioxide that's formed during fermentation.

Reflection:

The pretzel recipe turned out great! The pretzels had a nice texture , flavor, and rose quite well. Looking back on the recipe the team has concluded that we needed less slat and more yeast and sugar. The salt is used for flavor and ensuring the bread has a tougher texture. In the team's opinion the pretzels could be made with a softer texture; therefore, removing some salt would help the bread obtain that texture. More yeast could also be added to make the pretzels fluffier. The yeast would help this because it would let off more CO2, helping the dough rise. Lastly, the amount of sugar could increase. This is because it would help the yeast activate and grow quicker, overall helping the pretzels maintain a lighter texture. Also for the flavor more sugar and cinnamon could be added to make the bread taste even better.