The amount of dry yeast needed for 500g of flour depends on the type of bread you're making, the desired rising time, and personal preference. As a general guideline, you can use anywhere between 1 to 2% of the flour's weight in dry yeast.
Let's calculate the range:
1% of 500g flour = 0.01 * 500g = 5g of dry yeast 2% of 500g flour = 0.02 * 500g = 10g of dry yeast
So, you would need between 5 to 10 grams of dry yeast for 500g of flour. Start with a smaller amount and adjust based on the rising time and desired results. Keep in mind that longer fermentation times require less yeast, and a slower rise can improve the flavor and texture of your bread. Additionally, factors like room temperature, humidity, and the strength of your yeast can also influence the amount needed.