This is a follow-up to the prior water input testing, using Volvic and filtered tap water to brew both Rou Gui and sheng pu'er (a Lao Man E version, not the best choice, sorting out results past that bitterness). In that testing Volvic brewed infusions were clearly better for both types in the first and second infusion, and not quite as positive as the filtered tap water versions in the 4th and 5th infusions. I guessed about why in that post, but I'm really not certain.
It seemed better to try this using a mild tea version, something flavorful enough that results in that range would stand out, with feel and aftertaste aspects to evaluate, but with a generally mild tone making finer distinctions stand out better. Alishan oolong should work better. I had a couple of samples of what should be pretty good oolong left to try from Song Yi tea, the Taiwan based vendor source I'd reviewed a Brown Mountain (Bulang) sheng pu'er and Mannuo sheng from.
Those both were a lot better than I expected, and a good value for the quality level, so it seemed the two oolong samples they sent would probably be even more interesting, for actually being Taiwanese teas. I just never got back to trying them. Those reviews were in July and September of this year; it can work out like that, when lots of vendors send samples to try.
at the station nearest to home).
I'm filtering this local water too, so whatever is in it is reduced, but I don't have measurements for anything but free chlorine and total chloride levels. I'm more concerned with calcium, magnesium, and total dissolved solids measurements, which they don't provide.
the ph monitoring result just now
I did turn up a dated 2014 study of mineral content of water sources in Thailand, including Bangkok tap water, which may or may not pass on some idea of what was in that water:
There's really no guarantee that's at all relevant to what I'm using to make tea five years later, and again to repeat, whatever had been in that water was partly filtered back out. The last water test review post included some real-time measurements (of free chlorine, chloride, and turbidity), just not including calcium, magnesium, and total dissolved solids values.
Background on the Song Yi Alishan oolong:
It would work to cite more input about the tea, even though I tend to see light Alishan as varying more by quality level than other factors, so basically it's something you judge for yourself once you try the tea:
Origin ：Tea-growing region with gravelly soil
Camphor Tree Lake Stone Table, Alishan, Chiayi County
Altitude ：1,500 to 1,700m above sea level
Cultivar ：Qingxin (Green-Core) Oolong
Flavor ：Orchid aroma, Almond Peach scent
On their sales page 150 grams of this is selling for $45, so $15 per 50 gram amount. In retrospect, after trying it, that sounds about right; the version quality is pretty good. It would be a lot easier to find versions selling for in that range that weren't as good than it would be to find a better quality example selling at the same price, which would seem unlikely.
Versions can get better than this, emphasizing floral range just a little more, dropping back the limited vegetal range, bumping intensity or thickness a little, or that one characteristic mineral aspect, but this one seemed pretty far up the scale. For sticking within a moderate price range this is good quality and type-typical, just what you'd hope it would be.
Volvic: flavor is nice; it includes that nice floral range that signifies Taiwanese high mountain oolongs. Mineral undertone is nice, pronounced. This includes a little vegetal range that distinguishes the best light oolongs from quite good versions, or at least that's my take.
Filtered Bangkok tap water: not all that different. There might be a trace more vegetal range, slightly less high note floral, and a little more perfume base. For those minor differences it's about the same. Trying a faster infusion might help to tease out minor differences. Thick feel and pleasant aftertaste is common to both.
Volvic left, filtered tap water right
There is a slight brewed color difference; the tap water version is slightly darker.
Volvic: slightly improved; floral range hits even harder, perfume like base is even stronger. Vegetal range is still notable, a touch of green wood. Feel is thick, and mineral and floral both trail after as aftertaste.
Tap water: maybe slightly less high end note, slightly deeper perfume base, more mineral tone. Those last two differences I'd expect related to brewing the tea slightly longer, just probably not the first. That one almost odd, characteristic mineral taste is stronger, not completely unlike new car smell, a unique mineral range. It's flinty, as much as anything.
Making a "better" judgement is tough; they're just different. The Volvic version is better for being slightly sweeter with a touch more floral high note. The tap water version has a lot more mineral base and perfume depth, a less bright floral range closer to lavender. Vegetal range shifts in form a little in each, slightly stronger and just different in the tap water version.
I think the tap water may be brewing stronger, based on color and also taste and feel aspects, but I'm not sure why. Proportion, temperature, and timing are definitely all identical, or at least very close to it, so it's not one of those. The proportion is too high; I'm not as accustomed to judging rolled oolong amounts these days, and used the smaller version of tasting gaiwans, but didn't bump down the amount (probably a 60-70 ml version, versus the 80-90 ml versions I use more frequently).
Volvic: pleasant; sweet, rich, soft, intense but not overly so. Floral range is slightly different, but the difference is so subtle it is hard to pin down. The point here isn't to derive a flavor-list as much as specify differences anyway.
Tap water: more intense; it pops a little more. A touch more vegetal edge goes along with that, and more mineral. It comes across as creamier. These are definitely different, but again which is better would be a judgment call. The higher intensity is nice but a touch more vegetal range comes with that.
More of the same, and I won't trail this tasting out to 8 or 9 rounds to see the whole cycle. It's interesting that the prior pattern of tasting two other teas didn't hold, that the Volvic didn't seem clearly more positive early on, and then the tap water better after the 4th infusion.
I thought I probably did like the Volvic version slightly better on this fourth infusion, that being a little lighter and sweeter worked out better, versus there being a bit more vegetal and mineral range in the tap water version. But the tap water version was fuller in feel, and on the fifth infusion I thought it was more positive for that reason, with flavor differences secondary to that distinction in that round.
Potential next steps:
Not much to conclude; the two outcomes were different, but neither was really notably better. The Volvic version was a bit lighter and sweeter, the tap water outcome richer in feel, heavier in mineral, and in some cases it had slightly more flavor intensity. More than that flavor aspects just shifted slightly, in ways that was about as neutral as related to being positive or negative.
I suppose it's some comfort that it seems to not make much difference. Using Volvic, cited as some people's favorite in online discussion (which of course others disagree with) didn't prepare notably better tea than filtered local tap water. Oddly it was a lot more positive for the first two rounds of brewing the Rou Gui in the last post. And it was probably slightly more positive early in the infusio cycle for the Lao Man E sheng as well, but for both that bitterness hit so hard "better" was about sorting past that in those two infusions. This oolong never really matched that outcome, or the tap water version becoming notably better in later infusions.
I think people could have expected one or the other to be better, and based on that expectation and a positive interpretation could have judged that either one of these outcomes was clearly better. It seems natural to say "depends on preference" instead, but it's not as if flavor was better for one and feel better for the other, as if an aspect category worked out better using one of the water sources. Although these seemed relatively different prepared side-by-side I think for tasting them days apart prepared using the two water versions it would be hard to separate out that difference. The basic character and aspects profile was the same.
I could keep going, trying other versions of water. This didn't cover RO (reverse osmosis) water, a version stripped of almost all mineral content. There are other types of water at home (my wife is into mineral water these days, for whatever reasons), and I could run this again prepared using a number of different versions. It would be interesting checking out results using a water type that's very high in mineral content, with this Volvic seemingly on the moderate end of the scale, especially related to calcium and magnesium levels. I'm not sure that I'll keep on with this for now though; it adds a good bit of messing around to tasting, and I have teas around to try that deserve more attention than this tasting format allows for.