Happy New Year, all. Allow me to begin this one with a few skeptical (as
distinct from cynical) thoughts on brewing. Long-post alert; please trim
largely if replying.

There's an old saying that there are two kinds of people: the righteous
and the unrighteous. And the righteous decide which is which. Hoping to
avoid that trap, I'd like to observe that there are two kinds of tea
aficionados: those who like to be very precise in all their
manipulations, and those who are (or appear to be) casual or even
sloppy. The first kind further divide into those who use scientific
tools like digital scales, thermometers and timers, and those who find
precision in ritual, counting breaths, reciting mantras, etc. The second
also divide, into those who use a combination of experience and
sensory signals to provide needed cues for a behavioral precision, and
those who just like to see what emerges by happenstance.

I suggest that all four groups have exactly as much fun, enjoy their tea
to the same degree, and make equally fine company. They may also have
equivalent tacit knowledge of tea, though perhaps not the same ability
to express it explicitly.

The largest difference, in fact, may lie in what used to be called "the
story" and has now been elevated to "narrative." This is where myth and
magic come in. I suggest that as working definitions, myth is a body of
formal knowledge that may once or somewhere have been true, but that is
largely or entirely untrue here and now, or at least not reproducibly
true across situations. Magic is narrative about why and how things
work, told so compellingly that it influences what people experience
irrespective of what's in their cups. (And both often use the language
of science, though not its data, methods or epistemology.) Both have
roots in testable fact, but have become remote from any kind of causal
proof, reproducibility, or mechanistic basis. Examples could include the
injunction to match pot and leaf shape (come on!), the compelling effect
of certain clays or metals (just throw an old silver spoon or shards of
a dropped Yixing into a glass pot, and save a few shekels), or the
mid-infrared emissivity of some magical charcoal (first wash off the
clay, dirt and ash, then draw conclusions about operationally irrelevant
subtleties).

So are fact and science better? Better for what? We (most of us) are not
trying to create the next encyclopedia of tea truth, just to share what
brings us pleasure. And on the way, compare notes on what leaf and
equipment from what vendors, and what methods applied in what
circumstances, and narratives about it all seem to make us the happiest.
Sometimes the tenets of science serve us well: propose, test and confirm
or falsify hypotheses, run controlled experiments with managed
parameters, document both apparent conclusions and nulls or noise. This
quickly brings us to some generally (not universally!) held heuristics,
like using cooler water for greens and boiling for reds, ways to
maintain freshness, what regions and packers and times of year most
reliably produce the best teas. But even these aren't absolute; witness
certain discussions about cupping all teas at the boil, or the
definitive superiority of FF DJs, or the persistent canards about water
source, freshness and other aspects.

From my point of view as student (and occasionally teacher), the
important meta-learning for all on the path is that almost all tea
"knowledge" is only situationally useful - and that establishing one's
own tastes and pleasures is the most urgent task, after which
refinement, broadening and deepening will happen anyway. In other words,
take everything as a guide, and almost nothing as a rule.

For quite a few years, I've been on a private quest to determine some of
the key parameters of brewing technique that lead to more useful
real-life control than usual instruction offers. The purpose, per the
four categories above, is not rigor, but just some idea of where best to
play. A life in the lab notwithstanding, I almost never use measurement
equipment of any kind in brewing. But I still seek ever-more precise
distinctions in aroma, appearance and other signals to guide getting the
best of each steep.

This quest has led to some categories on which many of us have already
written. A few I'm still exploring (and on which I'd welcome others'
thoughts) include:

- The irreversibilities: over-ripening, over-roasting, over-aging,
overheating and oversteeping.

- The non-reciprocity between steeping time and brewing temperature.

- The effects of steeping time vs. intersteep time in gongfu, and the
interactions of common ritual or quasi-technical activities (e.g.
deliberately incomplete draining) with both.

- Distinguishing between the effects of brewing and drinking temperatures.

- Distinguishing the effects of enzymic reactions before kill-green
(so-called fermentation) from those of roasting, and both in turn from
passive chemical oxidation and microbial/fungal action, especially with
Pu-erh and other "live" teas.

One specific question in this portfolio is how far to break down pieces
of cake when brewing. This mainly applies to Pu-erh, but numerous other
fine teas are likewise available in pressed form. There seem to be three
main schools of thought on this:

- Neatly pry off one intact chunk and drop it in the gaiwan or pot
complete.

- Take it apart it up somewhat, either a random mix of large and small
pieces as it breaks, or a careful division into smaller chunks of
roughly equal size.

- Complete dissection almost into individual leaves, usually with care
to avoid breaking them if possible. (Or, in some cases, including some
deliberate fragmentation.)

There's no doubt that these produce different results. Perhaps the
simplest model has each leaf or fragment leaching out at some rate once
it is exposed to water. (The real situation is much more complicated and
interesting as extraction rates depend strongly on leaf hydration in
several ways, some non-linear or history-dependent.)

If uniformly divided single leaves are well-mixed with water, the amount
of material extracted per unit time will follow some kind of curve that
increases rapidly with hydration and temperature, then tapers off at
some rate depending on various binding, solvation and diffusion effects.
So the uniformly divided leaf offers a sort of baseline of what the tea
"ideally" delivers over time under a particular set of conditions.

Having the leaf pressed into lumps can then be understood as overlapping
the same curve repeatedly, smeared over time: when the first-wet leaf is
completely depleted, there is also material just "peaking" and some in
its first extraction. In certain cases, each steep in the middle of a
long series might resemble the result of pouring all into one mixing
vessel, or of doing a single long steep with all of the leaf divided.

As some of us have found, though, this is not generally a good
description of the experience. Key factors probably include the widely
variant rate of extraction of sugars and simple amino acids vs. more
highly condensed polyphenols, and flavor fatigue and thresholds. The
latter leads into the whole area of flavor balance vs. concentration
(which lends itself to some easy and revelatory dilution experiments),
another very import reciprocity failure in brewing. Those who regularly
use gongfu approaches with young sheng Pu-erh and dan cong oolongs are
especially aware of how small changes in multi-steep timing can
transform astringent mouthwash into nectar.

My own interest in this area arose from experiences with really
well-aged (in time and technique) sheng Pu-erhs, between 30 and 100
years old. The whole flavor-profile-with-dilution effect really came
forward, as the older teas tend to extract very quickly at the beginning
and then keep yielding appealing brews over twenty or even thirty
subsequent steeps.

My question was/is whether the power of the early steeps might be
carried over into those following, without compromising the smooth
delicacy of the latter. Not being economically equipped to do a full
experimental series with 1950s Blue Label, I've mostly been playing with
bingcha in the 10-year range. The game goes like this: break up the cake
into small flakes, steep a few times, then start adding small pinches of
fresh dry leaf every few rounds.

The results have been variable but compelling. In many cases, I've been
able to get strength and smoothness in pleasing collaboration. This
makes a case for starting with large chunks and letting matters unfold
as they will, but I've found this to yield poor control - often
too-rapid wetting of the whole mass, without the later boost; or too
slow, with fresh leaf always overpowering the quieter late notes. So I'm
starting to do the add-a-pinch routine more often.

Although this works pretty well with my favorite oolongs as well, I've
mainly been testing the approach with Pu-erhs. Another observation in
this class is that *small* amounts of shu pu-erh can work very well with
a sheng base. Since shus continue to extract almost forever, this lends
credibility to the practice of mixing sheng and shu in a single cake.
But my limited experience suggests that the ratio as supplied is way off
optimal; the smoothest sheng-like experience seems to happen with only a
few percent of shu added.

All early results. Your mouthfeel may vary. I hope some here will add
their own greater wisdom.

Salubrious sipping to all-

DM