science badge Question

Question-How does milk become yoghurt.

Hypothesis- put cold milk and whisk the milk and cream together.

materials- Milk, yoghurt 

Acidophiles                                                                          
                                                                                           
Its a bacteria used to make yoghurt                                        
It helps the intestines by cleaning                                        

what temp. does bacteria reproduce? 37 C
What temp is a fridge? 4-6 C
what is the healthy temp of the human body? 37 c                        

                                                               method 

In a beaker add 150mls of trim milk and 2tsps of acidophilus youghurt. stir to mix. leave out over night repeat with cream and blue(full)milk

Observations- trim milk is normal and whiter then the others.

                    -blue milk whiter then cream and a bit bubbly.

                    -Cream look yellow and has more in it.

blue Milk-

-what does look smell like?it looks like/smell like? It looks like milk but smells like nothing

-what happened to change it? bacteria  reproduced, fed of the sugar in the milk,Trim milk made it thinner yoghurt than blue milk or cream because it has less sugar 

-was my hypothesis right/or wrong? wrong,why because I did how to male it