steanze wrote: ↑
Wed Jul 21, 2021 10:41 am
LeoFox wrote: ↑
Wed Jul 21, 2021 10:29 am
I started looking into porosity under the assumption that porosity scales with rounding. However, I've found at least with my limited sampling of pots, this is not the case and impact on tea is potentially a much more complex issue than just porosity. I wish I had more pots to play with but unlike some on here, I am limited by how much I can spend both in terms of money and time.
I looked at the analyses you did, and the tests you ran are very cool. It's great that you took the time to collect those measurements. I also agree with you that "porosity" defined as % of empty space is in many ways too simplistic, and that for instance void space accessible from the surface is probably more relevant. The structure of this space is likely to also play a role (i.e. two pots might both have 1% increase in weight when wet, but the average size of void spaces may be different between the two: one might have many small cavities, the other might have fewer larger ones).
Regarding your measurements, I am a bit concerned about the strategy of weighting pots once they are "visually dry". It seems hard to use this as a reliable objective criterion. Is it possible that some clays look "visually dry" after different amounts of drying, because of the clay's composition? Is it possible that letting the pot become visually dry on its own vs patting it dry with a cloth would lead to different amounts of water removal? I worry that these sort of things might make it hard to find a relationship between porosity and effect on tea, because of noise injected by the variation in terms of when a pot is deemed to be "visually dry". Maybe one way to test this would be to take multiple measurements for the same pot, and evaluating how replicable the measurements for one pot are. I still think it's great that you are working on taking precise measurements, that's a step in the right direction and one that not many of the rest of us had bothered to do, so thanks for helping to push the understanding of the effects of clay on tea further!
Thanks for your kind comments!
Yeah this drying issue worried me too- and that is why I did repeat it a few times but did not show the results here. They have a 0.1% change in mass error. That is why I decided to delete all my results for those pots that showed less than 0.1% change in mass, which works about to about 0.06-0.09g for my different pots.
The structure of this space is likely to also play a role (i.e. two pots might both have 1% increase in weight when wet, but the average size of void spaces may be different between the two: one might have many small cavities, the other might have fewer larger ones).
This is a very good point and I am not sure how to address this other than place it in the discussion as we often do to satisfy the reviewers
What I am really shocked about is how long it takes a very porous pot to dry. That hqsn literally takes more than 40 hours to dry while a similar sized pot takes less than 5 minutes.
I really am tempted to hunt for more super porous pots but my budget...
Perhaps the ideal would be if several pots can be made with same shape and similar volume and same clay but with different firing procedures to achieve a range of porosities - and then tested side by side multiple times with one tea and by a group of experienced tea drinkers that have shown a degree of alignment. But who can and would be willing to do this other than a teapot/tea company? And if so, who can trust their report since they have a profit motive?