Don't use a fixed grinding scale when playing coffee. You should know that the density of each bean is different from the baking degree, and the required scale will not be the same. The scale of extremely hard beans or shallow baking can be slightly adjusted, and the deep baking can be adjusted to be thicker. If you think a bean tastes bitter and salty with a scale of #3, this is over-extraction. Adjusting the thickness to #3.5 or #4 will obviously improve the bad taste spectrum, and vice versa.