Fermentation Lab Report
Title: Confirming the Presence of Fermentation in the Conversion of Milk to Kefir
Authors: Michael Ahrens, Nicholas Fiore, Garrett Hages, Melissa Cullom University of Kansas, Biol 402, Fall 2014, 3:00pm room 6040
Abstract:
In this experiment milk was fermented into Kefir, then a series of tests were used to confirm that fermentation actually occurred. The tests used to confirm the fermentation were a gas production test, pH test, Gram stain, and turbidity test. The results showed during the conversion of milk to Kefir there was gas produced, a decrease in pH, more bacteria present, and an increase in absorbency. The results proved that fermentation occurred with three positive confirmatory results from the gas production, pH, and turbidity tests, while the Gram stain test acted as a negative confirmatory test.
Introduction:
The main goal of this experiment was to successfully ferment milk into a yogurt-like product called Kefir. The fermentation is accomplished with a symbiotic combination of different bacteria and yeasts. The main type of bacteria found in the fermentation of milk to Kefir is Lactobacillus. Lactobacilli ferment the lactose found in milk and produces lactic acid, contributing to the sour taste, characteristic of Kefir. The fermented product, Kefir, is not know only for its taste, but more so for the many health benefits if can have for the body.
Experimental Procedures The first step in this experiment was to make the fermented kefir product as well as a control. Two bottles were filled with milk; kefir grains were added to the first bottle to act as the experimental sample, and the second bottle, which contained only milk, was used as the control sample. A rubber glove was placed on the top of each bottle to act as a gas collector, and both bottle were allowed to sit for twenty-four hours. The first test used to confirm the presence of fermentation was to test for the presence of Carbon dioxide. This was carried out by checking the gas
Authors: Michael Ahrens, Nicholas Fiore, Garrett Hages, Melissa Cullom University of Kansas, Biol 402, Fall 2014, 3:00pm room 6040
Abstract:
In this experiment milk was fermented into Kefir, then a series of tests were used to confirm that fermentation actually occurred. The tests used to confirm the fermentation were a gas production test, pH test, Gram stain, and turbidity test. The results showed during the conversion of milk to Kefir there was gas produced, a decrease in pH, more bacteria present, and an increase in absorbency. The results proved that fermentation occurred with three positive confirmatory results from the gas production, pH, and turbidity tests, while the Gram stain test acted as a negative confirmatory test.
Introduction:
The main goal of this experiment was to successfully ferment milk into a yogurt-like product called Kefir. The fermentation is accomplished with a symbiotic combination of different bacteria and yeasts. The main type of bacteria found in the fermentation of milk to Kefir is Lactobacillus. Lactobacilli ferment the lactose found in milk and produces lactic acid, contributing to the sour taste, characteristic of Kefir. The fermented product, Kefir, is not know only for its taste, but more so for the many health benefits if can have for the body.
Experimental Procedures The first step in this experiment was to make the fermented kefir product as well as a control. Two bottles were filled with milk; kefir grains were added to the first bottle to act as the experimental sample, and the second bottle, which contained only milk, was used as the control sample. A rubber glove was placed on the top of each bottle to act as a gas collector, and both bottle were allowed to sit for twenty-four hours. The first test used to confirm the presence of fermentation was to test for the presence of Carbon dioxide. This was carried out by checking the gas
References: 1) Ahrens, Micheal L. Figure 1. 2014. Micheal Ahren 's Phone, Lawrence, KS. 2) Cullom, Melissa. Figure 2. 2014. Melissa Cullom’s Phone, Lawrence, KS. 3) Smith, Ann C., and Marise A. Hussey. "Gram Stain Protocols." Gram Stain Protocols. ASM Microbelibrary, 30 Sept. 2005. Web. 23 Oct. 2014. Figure 1 Figure 2