1. Gelatinisation of starch
AGO:
To understand the process of
starch gelatinisation when making a white sauce (also known as a Blended , Roux or Bechamel sauce).

2. What happens when a starch is heated in a liquid?
Starch consists of tiny granules. They do not dissolve when mixed with a liquid but are suspended in the liquid.
Gelatinisation occurs when starch granules absorb the liquid during heating. This process starts at 60C, the liquid will start to thicken at between 75 and 86C. However gelatinisation is not complete until boiling point is reached.
As heating continues the starch grains swell to more than five times their normal size. The granules burst releasing the starch which forms a gel with the liquid. This thickens the liquid.

3. Heat starch granules in liquid
Starch gelatinises when heated in a liquid, producing a thickened liquid

4. Starch granules become swollen

5. Starch granules burst

6. The liquid thickens and gelatinises

7. Now watch the video on gelatinisation
Digital text book page 119
Watch demonstration of starch solutions before heating, during heating after heating.
How do we add more starch to make the sauce thicker?
What happens if we add powdered starch straight into a boiling sauce?
From what you have learnt, how do you thicken a sauce without it going lumpy?

8. task Complete the cauliflower cheese questions
Use pages of the digital book to help you understand gelatinisation.
Bring ingredients and an oven proof dish to make bread and butter pudding.