This post is a response to a reader question.
Summary (for an average six-year-old)
(Based on: Peanut Butter and Jelly)
- First you take the milk and you heat it. (You heat it.)
- Then you take the milk and you cool it. (You cool it.)
- Then you take the bacteria and you add it. (You add it.)
- Then it gets fermented. (Fermented.)
- For your yogurt... white yogurt... and berries.
Explanation (for a smarter six-year-old)
The bacteria used in the fermentation process are Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus which convert the lactose into lactic acid (which is what builds up on your muscles when you exercise, but doesn't degrade performance as previously thought).
Aside from the that the first summary captures the essence of the process.