Back to topics

From cream to butter: rearranging fat and water

Churning brings fat together and separates liquid, helping turn the mixture into butter, where fat forms the continuous phase around small water droplets. What changes is the arrangement of the mixture, not simply how much it has been stirred.

5–7 min

Questions you could explore

  • Why does reversing which phase surrounds the other change the result?
  • What changes during churning that allows fat globules in cream to form butter?

Start reading

Ready to try your ideas aloud?

Your topic carries over. Record up to 2½ minutes, depending on your plan.

Food

Why bread dough rises

The holes in a slice of bread are a record of what happened inside the dough. In ordinary yeast-raised wheat bread, making gas is only part of the story: the dough also has to hold it.

3–5 min
Food

How does milk become yogurt?

Yogurt begins with milk, but its tang and texture develop as starter bacteria change the mixture. Their use of milk sugar and the resulting acidity connect the microbial activity with what ends up on the spoon.

3–5 min
Food

Keeping oil and water together in mayonnaise

Pour oil and water into a jar, shake them hard, and they will quickly separate back into two layers. Yet mayonnaise stays a thick, stable sauce because vigorous whisking breaks the oil into microscopic droplets, while emulsifiers in the egg yolk coat those droplets and stop them from recombining.

3–5 min
From cream to butter: rearranging fat and water | Speech Topic | speaking.app