Curiosity leads to discovery, and so it was that mine led me to the online discovery of various studies into what is in tea that affects flavor. And being the kind-hearted, love-to-share (except chocolate) type of person I am, I want to share some of this info with you. It may aid you in selecting teas more suited to your palate.
Many of you tea drinkers know that a first flush Darjeeling tea will taste different from a second flush Darjeeling tea. That a green tea will taste vastly different from a black tea. And that an Assam CTC tea will taste different from an Assam orthodox tea. You know that harvest time, oxidation, and overall style of processing (machine, hand, steps used, etc.) will all affect tea flavor. You don’t always delve into why this is so, just as many folks don’t delve into the intricacies of electricity to perform the simple action of turning on a light. It’s not necessary but can be quite fascinating. So is looking into what’s in tea leaves that stimulates our tastebuds and affects that tea flavor.
Basically, tea contains volatiles (substances that stimulate your olfactory sense) and various tastants (molecules and ions that break away from the leaves and stay in the water during the steeping process). A study from 2009 identified 26 volatiles in teas from Indonesia, Kenya, and Ceylon. The amounts vary per tea-growing region, with these being the most common:
- 2-Buten-1-one, 1-(2,6,6-trimethyl-1,3-cyclohexadien-1-yl)-, (E)-
- 3-Hexenal, (Z)-
The relative amounts of these and other volatiles will be one of the factors in determining tea taste.
And then there are these biochemical compounds (tastants) responsible for taste (you may want to get comfortable here – it’s a long list with even longer names):
- Polyphenol (astringent) — One type is catechins (flavanoids) which has eight different types: catechin, epicatechin, gallocatechin, epigallocatechin, epicatechin gallate, catechin gallate, epigallocatechin gallate, and gallocatechin gallate. Taste of each:
(+)-Catechin, (-)-Epicatechin, and (-)-Epigallocatechin were bitter with sweet aftertaste with thresholds of 51.05mg/100mL H2O, 45.53mg/100mL H2O, and 35.19mg/100mL H2O, respectively. (-)Epicatechin gallate and (-)-Epigallocatechin gallate were bitter and astringent with 18.12mg/100mL H2O and 20.15mg/100mL H2O as threshold, respectively.
In brewed tea, there are approximately 0.57% of (-)-Epicathechin, 2.15% of (-)-Epigallocatechin, 0.61% of (-)-Epicatechin gallate, 2.03% of (-)-Epigallocatechin gallate (Yamanishi 1990).
- Amino acids (brothy) — 60% theanine (5-N-ethylglutamine) plus principally aspartic, glutamic, serine, glutamine, tyrosine, valine, phenylalanine, leucine, isoleucine, and asparagine which forms during withering. From these, volatile carbonyl compounds form during processing: glycine forms formaldehyde, alanine forms acetaldehyde, valine forms isobutyraldehyde, leucine forms isovaleraldehyde, isoleucine forms 2-methylbutanol, methionine forms methional, phenyl alanine forms phenylacetaldehyde.
- Caffeine (bitter) — When combined with polyphenols, it adds a brisk taste/sensation and a creamy property that develops when the tea cools.
- Theaflavins (astringent) — Produced when polyphenols react with other compounds. Theaflavins go through further chemical reactions, creating thearubigins.
- Thearubigin (ashy and slight astringent) — Created from theaflavins and responsible for the specific, desired flavor and color characteristics of black tea.
- Tannin (strong astringent or pungent) — Congeals proteins on the top of the mucous membrane layer of one’s mouth and makes the tissues contract.
How much of the volatiles and compounds are present in a tea will determine how it tastes. And terroir is one thing that determines these amounts, according to numerous studies at professional labs and universities. The taste profiles include things like:
- Almond — Slightly cherry-pit like.
- Animalic — Like animals and their habitation.
- Asparagus — Slightly brown, slightly earthy.
- Beany — Somewhat musty earthy.
- Brown Spice — Cinnamon, nutmeg, allspice.
- Citrus — Aromatics associated with lemons, limes, oranges, etc.; could also contain a rindy note.
- Fruity — Sweet, floral blend, like ripe apricots, peaches, etc.
- Green Beans — Viney, green, slightly brown, woody.
- Green Herb-like — Like dry green herbs such as bay leaves, thyme, basil.
- Mint — Sweet, green, earthy, pungent, sharp, menthol.
- Seaweed — Like shellfish, fresh fish, and ocean vegetation.
- Spinach — Green, slightly musty, earthy.
- Tobacco — Slightly sweet, slightly pungent like cured tobacco.
With all of the above in mind, remember that your interpretation comes into play here, too. How do you know if something tastes like cured tobacco, for example, if you have never experienced it? Same goes for shellfish (lots of folks are allergic and so are not familiar with the taste), and a host of other of the flavors some teas are supposed to have.
Something to keep in mind as you sip. Enjoy!
See also: Some Thoughts on Terroir and Tea
See more of A.C. Cargill’s articles here.
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