Never underestimate the benefit of well-crushed grains. If your milled homebrewing grains are too coarse, then you will have weak tasting beer. On the other hand, if you crush them into a flour-like texture, they will be too fine and get stuck during the sparging process. Moreover, the presence of finely milled grains can create a hazy or cloudy-looking beer.
An efficiently crushed grain does not produce flour powder; it just separates the kernel from the husk. The endosperm should be broken but not separated from the shell; this allows for better flow through the grain bed. In addition, proper milling leads to better conversion of starch to sugar and encourages enzymatic reactions.
You can mill your homebrewing grains using a mortar and pestle or using a grain mill, which we have available on our website. However, milling and crushing your grains requires some precision and can be time-consuming. So....if you are still new to all-grain brewing, your best option may be to purchase freshly milled grains.