Ontario Teachers' Manuals: Household Management

by Ontario. Department of Education

EXPERIMENTS IN USING STARCH FOR THICKENING

(Any powdered starch may be used)

1. Boil 1/4 cup of water in a small saucepan. While boiling, stir into it 1/2 tsp. of cornstarch and let it boil one minute. Observe the result. Break open a lump and examine it.

2. Mix 1 tsp. of cornstarch with 2 tsp. of cold water, and stir into 1/4 cup of boiling water. Note the result.

3. Mix 1 tsp. of cornstarch with 2 tsp. of sugar and stir into 1/4 cup of boiling water. Note the result.

4. Mix 1 tsp. of cornstarch with 2 tsp. of melted fat in a small saucepan and stir into it 1/4 cup of boiling water. Note the result.

CONCLUSIONS BASED ON THE FOREGOING EXPERIMENTS

1. Starch granules must be separated before being used to thicken a liquid:

(1) By adding a double quantity of cold liquid

(2) By adding a double quantity of sugar