If you opt to use custard powder, we recommend Lion brand, which can be found online. When measuring flour, we spoon it into a dry measuring cup and level off excess. (Scooping directly from the bag compacts the flour, resulting in dry baked goods.) Active dry yeast needs to be dissolved in warm water. If the water is too hot or too cold, the yeast will not activate. The surface of the yeast mixture should be bubbly. Proofing time can vary depending on temperature and humidity level. Always judge by size of the dough (doubling or tripling) rather than time.