One of the existing waste in the community today is organic and inorganic waste, waste management must be done well, carefully, and serious. The garbage treatment in a city or region is the responsibility of all residents of the city or region, both the government and the community. This is indicated by the increasing incidence of waste management in some communities, both household and commercial. In addition, many community members are beginning to recognize and view waste as a resource that has economic value that can be utilized, for example as a raw material for crafts, processing that produces compost, and processing that produces energy, or make it more useful as done in this research is change the waste from rotten fruit waste become more useful material that is yeast.
Yeast is a single-celled plant belonging to the fungus family. Fermentation is a general term that encompasses air bubbles and air bubbles (aerobic and anaerobic) caused by microorganisms. In baking, most yeast comes from the Saccharomyces Cerevisiae microbial species. Yeast is a dough-growing ingredient with the production of carbon dioxide gas, the yeast consists of a small amount of enzymes, including proteases, lipases, invertases, maltases and zymases. The important enzymes in yeast are invertase, maltase and zymase
Invertase enzyme in yeast is responsible for the start of fermentation activity. This enzyme converts the sugar (sucrose) dissolved in water into sugar. Currently a lot of foods that use yeast in the process of making it, among others bread, tape, tempeh and many more. The manufacture of liquid yeast from this rotten fruit waste in addition to reduce the impact due to the environment is also useful as a material that can be used everyday.
In the manufacture of liquid yeast is used four different types of fruit, Pear (A), apple (B), banana (C), and monkey guava (D). The rotten piece of fruit is cleaned with a knife to remove the rotten part and picked up the still good parts then washed. A total of 200 grams of pear 200 grams of bananas and 200 grams of guava, 200 grams of apples included in a glass jar and added water as much as 500 ml.
Once incorporated in a jar or container, the mixture is stored for 5 days and observed daily for the growth of the liquid yeast. On the second day the white bubbles begin to appear in the container (except the monkey guava container) and after three days the white bubbles in the upper water of the fruit increase, after five days the liquid or filtrate is liquid yeast ready for use. From the experimental results that label D ( Monkey Guava) did not show the change, so yeast in cashew is not formed and not used in this research.
From the results of observation shows that the fruits that produce the most yeast is a banana (C) which is marked by the increasing number of white and bubbles contained in container C. After 5 days the solution is taken and separated from the fruit by filtering it. The yeast results are then stored and used to be tested by making tape and bread.
From the results of fermentation showed that on the second day there is a gas bubble in the water at the end of the hose and white bubbles on the bottle. On the third day of the gas bubbles in the water and the white bubbles in the bottle multiply, it shows that the fermentation process is successful because it has formed CO2 in the process of making this tape
The liquid yeast which has been made is applied to make the bread, as much as 2 eggs put into the container, then inserted three spoon of cornstarch and the egg is stirred until it is fused then added sugar as much as 3 tablespoons. Then 200 ml of liquid yeast was added. The dough is stirred until it is mixed in a mold and dyeed as desired. On making this bread.
In making this bread, the yeast from pear (A) fruit is used for green bread, yeast from apple (B) for black bread and yeast from banana (C) to make brown bread. From the experimental results show that the results made by using liquid yeast is no different from using yeast and fernipan used to make bread in general