My commercial grades from OP on down swim like a fish before saying hi to their maker. I noticed about half of my estate grades sink like a rock while the others will matte and slowly sink to their final resting place. For the ones that don't indicate any agony I wonder if that is normal? I'm thinking withering and oxidation may effect the dance otherwise any leaf will float. I recently switched back to a see through pot and wanted to make sure the phenomenon wasn't isolated. I even exposed some of my best swimmers to light and air for staleness and it didn't make any difference. Any ideas?
Main effect I would suggest is density of the leaf (tissue density, not bulk density) and speed of saturation of the tissue.
Leaf density is mainly affected by rolling time (can be from 30 mins to 200 mins), pressure (from light to heavy), and rolling table design (a myriad of variations). When withered green leaf is rolled the individual leaves are twisted (and small parts broken off), this twisting increases the density of the large pieces of rolled leaf. This will give a large "heavy leaf" that will tend to sink and as it absorbs water it will expand and swirl. Poorly twisted "light leaf" tends to float.
But the rate at which water is absorbed into the leaf is affected by the degree of wither - which influence the amount of cell sap squeezed out (for a given rolling pressure), and the viscosity of that sap.
It is noticeable that at different times of the year and with different wither conditions the rolled leaf is sometimes very sticky to the touch, and less so at others.
The viscosity of exuded sap depends on the a) amount of water removed in wither (a hard wither gives stickier juice), and b) the sap condition when plucked (climatic effects). When rolling ceases the exuded sticky juices are absorbed back into the twisted leaf (during oxidation). Subsequent drying at high temperature fixes the "glue".
A hard glued well twisted leaf will absorb water less quickly, thus will sit on the bottom of the vessel for a while - slow swirler. A hard glued poorly twisted leaf will float until it absorbs water slowly - slow sinker. A poorly glued heavy leaf will swirl quickly - fast swirler While a poorly glued light leaf will float momentarily as it absorbs - a fast sinker
All these effects will be influenced by water temperature. Water becomes less viscous as it is heated, thus leaves that might float in cold water would sink in hot. The dried oxidised sap (glue) disolves more quickly in boiling water than in warm, than in cold. Thus the "Agony" is perhaps best performed in the hottest of water.
Wow my vote for post of the year so far. That covers the infusions I've seen. I'll call "A hard glued well twisted leaf" the crab, "A hard glued poorly twisted leaf" the jellyfish, "A poorly glued heavy leaf" the seahorse, and "A poorly glued light leaf" the porpoise. I can see why estate teas are more crab than jellyfish. I'll also see some seahorse and the occasional porpoise. I did an infusion this morning where the seahorse spun off the crabs seemingly to defy gravity almost like fireworks. A lot of my commercial grades act like the seashorse. None of this translates into taste but I do enjoy an aesthetic tea infusion performance. I can sleep knowing that my expensive estate teas aren't a bill of goods. I'll try to isolate a tea type to the four marine types just for the heck of it. I'll probably give up after a week because the only thing that counts is the cup I'm drinking. Thanks Nigel.
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