1. Does the amount of sugar affect the yeast growth?
By: Michael Castro

2. Research Something Yeast Can Be Used For : Making Bread
Yeast are a small single-celled fungus and are classified in the in the Kingdom Fungi. They are so small that it can't be seen by your eye unless using a microscope. They are so small that it would take so many of them lined up side by side to measure an inch. Yeast use organic compounds as energy sources. It doesnt require any sunlight. This is called chemoorganotrophs. Yeast can be dried and kept for long periods. It needs water to live and grow. Having no water can affect the growth and development and can also kill it. It does not need light, but it does not need plenty of darkness. It uses sugar for energy, but can use starch. Too much sugar can affect the growth and even kill it. It needs a temperature between room temperature and body temperature or a bit higher. Too high temperature will affect the growth and may kill it. Too low temperature will not let the yeast grow at all and will affect the development. There is no exact temperature that will always work best in yeast growth, it varies in the temperature range in which they can grow the best. Even though there is no exact temperature its said that yeast grows best in warmth temperature and when its mixed with moisture. Yeast may live or survive freezing temperature under some conditions but with viability lowering or decreasing over a period of time. Yeast reproduces like all fungi. It may either have sexual or asexual reproductive cycles but the most common is asexual reproduction which happens by budding. Yeast is common in our environment. They often grow in sugar rich materials like in fruit skins, bread, all kinds of food. Yeast is so common in our environment that it can be easily found with insects and bugs. Yeast gets their food from any sugar, such as prutrose and dextrose. These sugars are found in apples and other fruits with sugar rich materials. They abstract the sugars out of the fruit by breaking the fruit down to double sugars then breaking those down to simple sugars. Yeast has a process of breaking down when it comes to eating. Many or some breads are made of yeast so this can help us understand that yeast is not always bad for us, so yeast is both good and harmful. If you eat bread nothing will happen because most breads are made of yeast. Only if you see yeast on top of the bread it means that its old and in bad shape to eat. The yeast that bread is supposed to have its put in the sough so its no able to be seen. Yeast gives off gas as they consume and digest sugars so the bubbles of gas become trapped in the dough, causing the bread to rise. Yeast is used in many different ways. Wine producers don't use wild yeast because they have some unfavorable traits. So they kill off the wild yeast and use yeast that have been domesticated to the needs of the production process. Yeast is nourished by dead, living plant or any animal matter. The ideal conditions of yeast is really high humidity and temperature and warmth mixed with moisture .In bad conditions though the yeast produces a second cell wall for protection and the yeast contents divides into four parts.This process is called ascospores.Then when favorable conditions return the ascospores burst to reproduce. When yeast reproduces by budding the adult yeast begins to swell on its surface. Then part of the parent begins to bud and a wall is formed between the parent and the new yeast. Then the new yeast may do one of two things. It may break away from the parent or it may stay attached to form a chain or a cluster. Budding is very quick and easy process. Its very easy to understand it. Yeast grows a lot faster on bakery bread. Most packaged breads from the store are stuffed with preservatives, which doesnt allow the yeast to growth on it. If bread gets wet too much, you'll get bacteria instead of yeast. Substances that contain sugar are the substances that yeast grows best on and its also their favorite thing to eat. By splitting in two or budding the yeast reproduces. Part of the cell wall of the yeast swells then forms a new growth or a bud. The bud turns into its own independent cell. Yeast is useful and important to humans in many ways. Temperature is very important to yeast growth. Yeast is used in bread, which is imperative, because most people eat bread. We could live without bread but it is still important worldwide. Yeast is any of various one-celled fungi that can cause the fermentation of carbohydrates, producing carbon dioxide and alcohol. Bakers put it in bread to make it rise. Yeast is also used for the production of beer and wine. Yeasts that are used commercially consist of masses of microscopic yeast organism. Yeasts are able to grow in foods with a low pH, and in the presence of sugars, organic acids and other easily metabolized carbon sources. During their growth, yeasts metabolize some food components and produce metabolic end products. Yeasts are grown in the laboratories on solid growth media or in liquid broths.
Something Yeast Can Be Used For : Making Bread
Bakers make yeast bread with many ingredients. They always a least have four ingredients. The most common Ingredients are eggs, milk, water, sugar or any other ingredients to get a better taste. The four most common are flour ,yeast, water and salt. Bakers use enriched dough for white bread. To enrich the dough bakers may use vitamins or any other time of mineral. Some special of dough conditioner is in most commercial dough. Most bakers use chlorine dioxide or potassium bromate to even out the textures or smooth the bread to make it softer to eat. Bakers to this because most people like the softer bread that any hard bread. Some bakers put calcium in yeast bread to reduce the bacteria and mold and stopping it from growing that why in some breads it takes a long time for the bread to grow mold, bacteria, yeast or fungi. There are actually two main processes to making dough into any type of bread. One of the process is conventional bread making and the other process is continuous bread making. Most of the bakers including home bakers and commercial bakers use the process of conventional bread. One this is that home bakers vary the process. When bakers use the conventional process or method both are right the ingredients are mixed one of two important main methods. One method is the straight dough method and the other method that is used is the sponge and dough method. In the sponge and dough method what happens is the ingredients are combined in two important stages. The first stage or step is to mix the yeast that you have all the yeast with some of the flour and water or if you have milk instead of water. Either of them is fine. Once all this ingredients are mixed this is now called a sponge. Bakers then let the dough rise for about 12 to 16 hours and for about 80°F to 90°F. Then all the other ingredients you are going to use are added to the mixture. Then it rises again for a little while. In the straight dough method all the ingredients are mixed at one Then it rises for about 3 hours at about 80°F to like 85°F. You might be wondering wight they use the conventional process instead of the straight doe well bakers like the dough to rise better so the more time the better it rises and it gets a better taste because all the dough is not put in all at once like the straight doe process.After these both processes the dough is then cut into a right shape or a right size depends how the baker wants it. Then it rises for a long period of time not that much. The bakers cook the dough at about 450° F. After the dough is cooked bakers use special equipment to mix the dough and the ingredients. Finally the bread is baked at any temperature after its done the bread is sliced and wrapped.

3. Hypothesis
If i add 1 cup of sugar to the yeast then it will grow or rise more.

4. Independent and Dependent Variables
Independent- Amount of sugar added to the yeast
Dependent- How much yeast grows or rises

5. Controlled Variables Amount of Water Amount of Yeast Size of Cup
Type of Sugar
Measuring Cup

6. Materials Measuring Cup 9 cups(Better if they are about 12cm long)
Yeast
Sugar
Water
Camera
Computer
Ruler

7. Procedures
Step 1- Get 3 cups and add ¼ cup of yeast to each of the cups.
Step 2- Add 1 cup of water to each of the cups.
Step 3- Add ¼ cup of sugar to one of the cups.
Step 4- Add ½ cup of sugar to the another cup
Step 5- Add 1 cup of sugar to the last cup.
Step 6- Place them somewhere where the yeast can rise or grow for 3 days.
Repeat these steps for the other trials.

8. Experiment Day 1- Trial 1 Green Card 1 cup sugar Red Card ½ cup sugar
Purple Card ¼ sugar

9. Middle Cup ½ cup of sugar
Day 2- Trial 1
Left Cup 1 cup of sugar
Middle Cup ½ cup of sugar
Right Cup ¼ cup of sugar

10. Left Cup 1 cup of sugar (3cm Grew)
Day 3- Trial 1
Left Cup 1 cup of sugar (3cm Grew)
Middle cup ½ cup of sugar (0cm Grew)
Right Cup ¼ cup of sugar (0.4cm Grew)

11. Purple Card ¼ cup of sugar
Day 1- Trial 2
Green Card 1 cup of sugar
Red Card ½ cup of sugar
Purple Card ¼ cup of sugar

12. Day 2- Trial 2
Left Cup 1 cup of sugar
Middle cup ½ of sugar
Right Cup ¼ of sugar

13. Left Cup 1 cup of sugar (2cm Grew)
Day 3- Trial 2
Left Cup 1 cup of sugar (2cm Grew)
Middle Cup ½ cup of sugar (0cm Grew)
Right Cup ¼ cup of sugar (0.5 cm Grew)

14. Purple Card ¼ cup of sugar
Day 1- Trial 3
Green Card 1 cup of sugar
Red Card ½ cup of sugar
Purple Card ¼ cup of sugar

15. Middle Cup ½ cup of sugar
Day 2- Trial 3
Left Cup 1 cup of sugar
Middle Cup ½ cup of sugar
Right Cup ¼ cup of sugar

16. Left cup 1 cup of sugar (1cm Grew)
Day 3- Trial 3
Left cup 1 cup of sugar (1cm Grew)
Middle Cup ½ cup of sugar (0cm Grew)
Right Cup ¼ cup of sugar (0cm Grew)

17. Data

18. Results
The yeast with the 1 cup of sugar grew the best than the others.

19. Conclusion
My hypothesis was if i add 1 cup of sugar to the yeast then it will grow or rise more. I was correct however when I did my experiment I found out that ½ cup of sugar doesn’t benefit the growth of the yeast and that ¼ cup of sugar benefits the yeast to rise better than ½ cup of sugar. Why is this? What I concluded was that equal amount of water and sugar benefits the yeast to grow the best. However having the equal amount of sugar and yeast also benefits the growth not as well as having the equal amount of water and sugar. Which explains what happened with the ½ cup of sugar which was that it was half the amount of the water and ¼ more sugar that the amount of the yeast so it was not really close to having equal amount of sugar and yeast or having the equal amount of water and sugar. That’s why ½ cup sugar doesn’t benefit yeast growth. So my final conclusion is that there are 2 ways to benefit yeast growth, having equal amount of yeast and sugar or having the equal amount of water and sugar which benefits it more. With yeast growth everything has to be balanced out to benefit the growth.