1. CATTLE’S MILK Group V

4. Smells bad but no visual changes 5 15:00 Smells bad but no visual changes 5 09:00 04.03.2008 Smells bad but no visual changes 5 15:00 Smells bad but no visual changes 5 09:00 03.03.2008 Smells bad but no visual changes 5 15:00 Smells bad but no visual changes 5 09:00 29.02.2008 No visual, chemical changes. 5-6 15:00 No visual, chemical changes. 5-6 09:00 28.02.2008 No visual, chemical changes. 6 15:00 Fresh cow milk 6 09:00 27.02.2008 OBSERVATIONS [2 o C] / pH HOUR DATE

5. Bad smell is very intensive, milk has yellow colour, water appered on the bottom of the test tube 4 15:00 Bad smell is very intensive, milk has yellow colour, water appered on the bottom of the test tube 4 09:00 04.03.2008 Bad smell is very intensive, milk has yellow colour, water appered on the bottom of the test tube 5 15:00 Bad smell is very intensive, milk has yellow colour, water appered on the bottom of the test tube 5 09:00 03.03.2008 Smells bad ,milk has yellow colour 5 15:00 Smells bad ,milk has yellow colour 5 09:00 29.02.2008 Smells bad ,no visual changes 5-6 15:00 Smells bad ,no visual changes 5-6 09:00 28.02.2008 No visual, chemical changes 6 15:00 Frsh milk 6 09:00 27.02.2008 OBSERVATIONS [20 o C] / pH HOUR DATE

6. pH decreased, bad smell is still very intensive, upper layer is solid, yellow, loads of sediment are occupying test-tube ’ s walls 4 15:00 pH decreased, bad smell is still very intensive, upper layer is solid, yellow, loads of sediment are occupying test-tube ’ s walls 4 09:00 04.03.2008 Bad smell is very intensive, water starts to appear on the surface of upper part which became solid. Some sediment appeared on walls of test tube. 4-5 15:00 Bad smell is very intensive, water starts to appear on the surface of upper part which became solid 4-5 09:00 03.03.2008 Milk smells badly, upper part becomes solid and turns yellowish 5 15:00 pH changed, milk starts to smell bad 5 09:00 29.02.2008 No visual or chemical changes 5-6 15:00 No visual or chemical changes 5-6 09:00 28.02.2008 No visual or chemical changes 6 15:00 Milk is fresh and liquid form 6 09:00 27.02.2008 OBSERVATIONS [35 o C] / pH HOUR DATE

7. We can observe how cow milk is acting after leaving it in those three tepmeratures. Starting from the heater ( temperature 35°C) we can observe that because of hot tempreature reaction of fermentation of cattle’s milk was the fastest and the strongest. It is the first sample which reached pH 4 and it happened after 6 days. In the room temperature this process was a little bit slower. It needed one more day to get pH 4. It is connected woth temperature of course because fermentation of milk comes mucha faster when the temperature is increasing. The third sample was put to the fridge with temperature 2°C. We can observe that thanks to the temperature which was the slowest the process of fermentation was also slower and never got the level of pH 4 but finished at 5. CONCLUSIONS

8. Photos of test tubes with milk during our observations Fridge (2ºC) Room (20 ºC) Heater (35 ºC)