Bread Science Fair 2021 Montessori Academy at Spring Valley School

R.B.

7th Grade Question

The question for my science fair is: If I vary the amount of yeast in bread, how much will it affect the bread? I chose this question because I see bread around me almost every day, and also I fit in with the requirements that I needed to do for my science fair. They invented it around 450 BC. Around 600 BC, the Background Information Persians invented the windmill system for milling grains, and the Mexicans made the first stone-ground corn tortillas around 100 BC. Bread. The thing we use a lot of. We use it to Finally in 1834 Switzerland made the first steel-roller. Instead of make sandwiches, we also use different variations of crushing the grain, the invention opened the grain, making it easier it like banana bread, and we use the crumbs for it to to separate the endosperm, germ, and bran. The history of bread, is make things like homemade mac and cheese. It is very an interesting topic. important and I think that we should learn more about it. How does the yeast affect the bread? Yeast is a single celled fungus. There are about 160 species of yeast, and a lot of the species, live around us. A lot of people are only used to the species The history of bread is a topic that I think is a produced in mass form: The beige granules that come in packets. very interesting thing.The first loaf of bread made was The organism rests, until it comes into contact with water. Once the in 8000 B.C in Middle East, specifically Egypt. The yeast is reactivated, the yeast feeds on the sugar in the flour, first thing to make bread was called a quern. It releases carbon dioxide, that makes the bread rise. The yeast also grinded up grain, and made the closest thing to bread, adds flavor, and the scent we relate with bread. Leavening comes in as we know as chapatis, or tortillas. Egyptians were two different forms: Baking soda, or powder, and yeast. Baking skilled brewers, and people thought that their skills soda and powder rely on chemicals between acidic, and alkaline mixed with the warm weather, made the first loaf of compounds to make carbon dioxide necessary to rise the dough, or sourdough bread. Bread progressed over the centuries, batter. Leavening agents would just be bubbles if there wasn’t and eventually, Romans invented the water-milling. something to contain them. That is where the flour comes in. There are a lot of different types of flour used in making bread, but the most used flour, is wheat flour. Starch is a thing that makes up 70% of the flour. Background Information It also helps with the making of bread. When the starch granules get striked by the enzymes in the yeast, the We use wheat flour more than others, because the flour, granules release sugar which the yeast feeds on. Starch contains two proteins: glutenin, and gliadin. When they it is also strengthens gluten, and absorbs water during combined with water, it makes gluten. As you knead the baking, which helps the gluten contain the pockets of gas dough, the gluten stretches and stretches. The gum-like from the yeast. Starch is really cool thing that is a big substance, fills with thousands of of gas bubbles, as the yeast part of flour. goes on it way and rises. The yeast is very important important to the bread. Yeast goes about 5,000 years back. The Ancient Egyptians used it to make bread originally, but they Leavening comes in two different forms: Baking soda, didn't care about the yeast fermentation process, and or powder, and yeast. Baking soda and powder rely on they believed that the yeast was a miracle. People chemicals between acidic, and alkaline compounds to make believe now that yeast was used before we started carbon dioxide necessary to rise the dough, or batter. writing anything! Hieroglyphics say that yeast was Leavening agents would just be bubbles if there wasn’t being used to make alcoholic beverages. something to contain them. That is where the flour comes in. There are a lot of different types of flour used in making I think that the history of bread, and yeast, and bread, but the most used flour, is wheat flour. how the yeast affects the bread, starch, and the science

behind yeast, are all very fascinating. I hope you learned something new!! Hypothesis

Since the yeast plays a very important role in bread making, I think that the yeast will make the bread rise, according to how much I put in. If I put in less, then i think it wouldn't be significantly changed but that would mean i have to scale the whole recipe down. If you want to do this experiment with me then here are the Materials Needed materials needed (This is for all of the loaves)

● 4 ½ cups of bread flour ● 13.5 cups of bread flour ● 1 packet of instant yeast ● 4 packets of instant yeast ● 1 tablespoon of salt ● 3 tablespoons of salt ● 5.25 cups of warm water ● 1 ¾ cups of warm water Procedure 1. In a standard size bowl, mix warm water, packet of yeast, and salt, and beat at about medium low until a sticky dough forms 2. Cover, and let rise in a warm place, for 2 hours 3. Line a sheet pan and dust with bread flour 4. Put the dough on the floured surface, fold ⅓ of the side closest to you, in the middle, repeat with other 2 sides. Finish by folding top ⅓ over past folds. Roll dough away from you using both hands, and pull it towards you to seal. Turn whole dough 180 degrees and repeat, until a small ovular shape forms. Cover and let rise for 1 hour. 5. Before you bake your dough, score top of the loaf 6. Cover the loaf with foil and tightly seal the foil over the rim of your pan. Bake at 425 degrees, for 30 minutes. Uncover your loaf and bake until an instant-read thermometer reads 205 degrees. - Results

Loaf 1 Loaf 2 Loaf 3 The first loaf turned out really I think that the second loaf did This last loaf, it was ok. It was good. It was a little harder on not turn out well at all. This is like the first loaf, but a little the outside than I expected, but it the loaf that I put not enough more sourdough-y. So i figured was still really good. I don’t yeast in, but they all looked like out that putting it in the fridge, think it tasted that sourdough-y normal sourdough loaves. This makes it more sourdough-y, because I did not put enough one tasted too salty, even though because this is the loaf I put in salt in. I put enough salt that the recipe the refrigerator, because i forgot called for. to do it last time .

Next time I could let it sit in the Next time, I could put it in the Next time I will make bread, i fridge after i let it sit for 2 hours, fridge, because i forgot to do will put it in the fridge for because i did not understand the that again. longer, and i will add a little less directions. salt, and i will bake it for a little less time, than I did. Result Pictures

Conclusion

I learned a lot of things from this experiment. I learned how to make bread, I learned the history of bread, I learned how yeast makes the bread rise, and how yeast feeds off of the flour. My hypothesis was sort of correct, because the yeast did not control how the bread rose on the third bread, because it just rose like the loaf that I followed the recipe with. This experiment was really fun, and i hope you had fun with me, if you made the bread. :) Pictures!

Another Yeast Cell Under a Microscope Parts of a Yeast Cell

Yeast Cell Under a Microscope Bibliography https://redstaryeast.com/recipes/platinum-instant-sourdough-boule/

Recipe https://www.exploratorium.edu/cooking/bread/bread_science.html#:~:text=Once%20reactivated%2C%20y east%20begins%20feeding,aromas%20we%20associate%20with%20bread.

How the yeast affects the bread https://redstaryeast.com/science-yeast/what-is-yeast/#:~:text=Yeast%20are%20single%2Dcelled%20fu0n gi.&text=It%20takes%2020%2C000%2C000%2C000%20(twenty%20billion,%E2%80%9Csugar%2Deatin g%20fungus%E2%80%9D.

Information about the yeast cell