Distribution is an aspect of preparing a shot that often gets overlooked or underestimated. Customers recognise tamping as an important barista skill — but while good tamping is essentially a fairly simple mechanical action, distribution covers a range of methods, and the ideal method is still up for debate.
Distribution from the Grinder
Good distribution starts at the grinder. The way the coffee lands in the filter basket from the grinder has a significant impact on the way a shot will run (G Davies, 2016). Ideally, the grinder would be designed and used in such a way that the grounds fall evenly into the basket right from the start, to minimise the amount of work baristas have to do to redistribute the grinds.
This means that depending on the design of your grinder, positioning and moving the portafilter during grinding may be the first step in getting a good distribution. More recent grinder designs have addressed this issue effectively, with adjustable forks or chutes to ensure the grinds land correctly in the basket. For example, it’s possible to make small adjustments to the position of the forks on most modern grinder designs. Or to change the angle of the chute where the grinds exit the grinder. If possible, adjust the grinder or hold the portafilter in such a way that the grinds fall neatly into the centre of the basket.
Distribution of Fines
Distribution also refers to the way particles of different sizes are distributed within the coffee, and in this respect some grinders may be better than others. According to 2009 World Barista Champion Gwilym Davies, who was part of the Nuova Simonelli project to develop the Mythos One grinder, some grinders spit grinds out unevenly. ‘The original Mythos dropped heavy particles close to the throat and lighter particles closer to the barista, so it brews from the back to the front of the basket’, he said. This problem was solved by the development of the clump crusher and by choosing a slower grind speed,