so we’re now beyond the results of the great distribution tool debate. my question is, has anyone been experimenting with their own distribution techniques and finding positive results?
i have recently been logging the tds and extraction of shots pulled to varying times and yields. i noticed a surprising amount of variance in the trending differences, even within one batch of coffee, having measured equal doses within a hundredth of a gram with an ohaus scale, having used consistent-as-possible hand tapping as distribution and having syringe-filtered the samples with vst espresso filters before refracting. the results were consistent enough to be useful to me, but i attribute a fair amount of the variance to uneven extraction. i’m sure some of that variance is in the nature of refracting espresso, but it seems obvious through experimentation, tasting and through reading the works of others that an even extraction is not only important, but is not very easy to achieve. for one thing, we are probably getting both over and under-extracted flavours simultaneously from our less than evenly extracted shots.
it seems an even extraction is likely happening when the espresso first starts to ooze out of the bottom of the basket everywhere simultaneously (for those of you with naked or bottomless portafilters). and this is probably only achieved when there is a perfect coffee density throughout the puck. further, a perfect density is achieved by the loose grinds literally having to be somehow evenly distributed throughout the basket before tamping, because an even tamp alone could still allow pillars of denser areas below it.
there are some distribution methods that smooth out the surface of the grinds, like the ocd tool and stockfleth’s method, but they seem to leave the lower grinds unaffected. as of yet, tapping the sides of the portafilter with the palm of the hand while sort of tilting the basket away from the tapping seems to be the most effective distribution technique that the world is aware of. https://baristahustle.com/blogs/barista-hustle/how-to-distribute-by-tapping perhaps hand tapping followed by the use of a surface tool like the ocd is even better, but a relevant matter is that hand tapping is probably not consistent from barista to barista, even within one shop.
our shop is curious about the possibility of a platform that holds the portafilter with the basket level and vibrates with almost imperceivably small, but fast and aggressive motions. this may not be practical in a more high volume shop but we shouldn’t let that stop us from experimenting, learning, and sharing our findings for others to build upon. something like a vibration tool that is successful in producing an even extraction might inspire something that is quicker to use, like a grinder that holds and vibrates the portafilter as it fills the basket.
perhaps an overlooked area of distribution has been how grinders distribute the grinds into the basket. i am currently building a prototype of a tool that fits between our grind chute and the basket, with the intention of distributing the grinds somewhat evenly right as they fall. i am planning on still having to do some hand tapping, but at least i won’t have to start by toppling a center pile. perhaps half of our current distribution time is used just getting the peak of this pile down below the rim of the basket. when an even distribution is the end goal, it is less than ideal to start with a peak in one area. i will be sure to share my prototype findings here.
there is a lot of forward potential in the field of espresso grind distribution, and discussion and sharing of theoretical ideas and findings is the way to get there. so if we have any other ideas, or have discovered something useful aside from the common surface tools, hand tapping, or stockfleth’s technique, let’s discuss it!