Making Yogurt with Kathryn & Jessica


1.  1 pint pasteurized milk

2.  1 carton plain yogurt

3.  Powdered skim milk

4.  Hot plate

5.  Beaker

6.  Thermometer

7.  Tablespoon & teaspoon



1.  Pour the pint of pasteurized milk into a glass beaker.  

2.  Add 2 tablespoons of powdered skim milk to the pint of pasteurized milk.  

3.  Bring the mixture to a boil over medium heat for 30 seconds, stirring constantly.

4.  Cool to 45-46 degrees Celcius.

5.  Add 1-2 teaspoonfuls of the plain yogurt using a sterilized spoon, and mix well.

6. Cover the beaker with aluminum foil, and incubate at 37 degrees Celcius for 9-15 hours.

7.  Analyze!!!  

*** The pH of your yogurt should be tested first with the plain, store-bought yogurt, and finally with your homemade lab yogurt.***  


Test the pH of your yogurt

Gram Stain


Directed by Dr. Cheryl Lindeman  |  Go back to the Biology Home Page  |  Credits