WDT Tool Use a fine needle or similar tool to stir the ground coffee in the basket, you can place a powder ring to prevent the ground coffee from being stirred out. The stirring action breaks up the agglomerates that occur when the coffee beans are ground, and at the same time distributes the coffee more evenly throughout the bed. This can improve the channel effect, making the extraction more uniform and the extraction rate higher. After testing, any tool larger than 1mm in diameter will have the opposite effect, such as toothpicks. In addition, it is also essential to use the powder needle to stir the powder evenly and carefully. The stainless steel needle is very tough. You can adjust the angle of the needle according to the illustration to fit your own coffee filter and espresso portafilter basket.