For your information, the flour-to-water ratio for tangzhong is always 1 (bread flour) : 5 (water). For instance from the recipe shown below you can make a batch of approximately 150g tangzhong.
Ingredients: (able to make 2 loaf of bread with 350g bread flour)
25g Bread Flour
125ml Water(could be replaced by milk, juice or 50/50 water and milk)
>Method:- 1. Mix flour and water in a small saucepan until without any lumps.
2. Cook over medium low heat, stirring consistently with a egg whisk or wooden spoon to prevent the mixture from burning while cooking.
3. The mixture will thicken up (takes about less than 2 minutes) while cooking, so once you see “lines” appear …