Time Out Tea

The Best Water for Making Tea
A cup of tea comprises of over 99% water so it is hardly surprising that the quality of the water used is critical to the flavour of the tea. Fine teas are especially sensitive to the type of water used.

The best water for making a cup of tea is low in mineral content, free of contamination and additives and high in oxygen content. The presence of these factors can all influence the taste of tea—so a good test is to try the water before you use it to make your brew. It the water tastes good, then it’s safe to use. If the water is tainted in any way, it’s best not to use it.

After that, the site says, the way you boil the tea is of extreme importance:

Re-using water in your kettle that has already been pre-boiled is not a good idea if you want to make a perfect cup of tea. Most experts agree that you should never re-boil previously boiled water, or boil the water for too long. As water boils, oxygen is driven out and the more it boils, the less oxygen stays in the water. Water that has already been boiled, like the water that usually sits in your kettle, contains much less oxygen than fresh water. Tea made with water that has depleted oxygen content loses its crisp, fresh taste.

Tea Tasting Terminology
(Taken from “The Book of TEA” – Antony Bugess)

Terms Describing Dry Leaf -
Black: A black appearance is desirable.
Blackish: A satisfactory appearance.
Bold: Particles of leaf which are too large for the particular grade.
Brown: A brown appearance in teas that normally indicates overly harsh treatment of the leaf.
Clean: Leaf that is free from fiber, dust and all extraneous matter.
Curly: The leaf appearance of whole leaf grade teas such as O.P., as distinct from “wiry”.
Even: True to the grade, consisting of pieces of leaf of fairly even size.
Flaky: Flat, open and often light in texture.
Gray: Caused by too much abrasion during sorting.
Grainy: Describes primary grades of well-made CTC teas such as Pekoe Dust.
Leafy: A tea in which leaves tend to be on the large or long side.
Light: A tea light in weight, of poor density. Sometimes flaky.
Make: Well-made tea (or not), true to its grade.
Musty: A tea affected by mildew.
Neat: A grade having good “make” and size.
Powdery: Fine light dust.
Ragged: An uneven, badly manufactured and graded tea.
Stalk & Fibre: Should be minimal in superior grades, but is generally unavoidable in lower-grade teas.
Tip: A sign of fine plucking, apparent in top grades of orthodox “Low Grown Type Teas”.
Uneven & Mixed: “Uneven” pieces of leaf usually indicative of poor sorting and not true to the particular grade.
Well Twisted: Used for describing whole-leaf grades, often referred to as “well-made” or “rolled”.
Wiry: Leaf appearance of a well-twisted, thin-leaf tea.
Terms Describing Infused Leaf -
Aroma: Smell or scent denoting “inherent character,” usually in tea grown at high altitudes.
Bright: A lively bright appearance. Usually indicates bright liquors.
Coppery: Bright leaf that indicates a well-manufactured tea.
Dull: Lacks brightness and usually denotes poor tea. Can be due to faulty manufacture and firing, or a high moisture content.
Dark: A dark or dull colour that usually indicates poorer leaf.
Green: When referring to black tea, refers to under-fermentation or to leaves from immature bushes (liquors often raw or light). Can also be caused by poor rolling.
Mixed or Uneven: Leaf of varying colour.
Terms Describing Liquors
Bakey: An over-fired liquor. Tea in which too much moisture has been driven off.
Body: A liquor having both fullness and strength, as opposed to being thin.
Bright: Denotes a lively fresh tea with good keeping quality.
Brisk: The most “live” characteristic. Results from good manufacture.
Burnt: Extreme over-firing.
Character – An attractive taste, specific to origin, describing teas grown at high altitudes.
Coarse: Describes a harsh, undesirable liquor.
Coloury: Indicates useful depth of colour and strength.
Cream: A precipitate obtained after cooling.
Dry: Indicates slight over-firing.
Dull: Not clear, and lacking any brightness or briskness.
Earthy: Normally caused by damp storage, but can also describe a taste that is sometimes “climatically inherent” in teas from certain regions.
Empty: Describes a liquor lacking fullness. No substance.
Flat: Not fresh (usually due to age).
Flavour: A most desirable extension of “character,” caused by slow growth at high elevations. Relatively rare.
Fruity: Can be due to over-fermentation and/or bacterial infection before firing. An overripe taste.
Full: A good combination of strength and colour.
Gone off: A flat or old tea. Often denotes a high moisture content.
Green: An immature, “raw” character. Often due to underfermentation (Sometimes underwithering).
Harsh: A taste generally due to underwithered leaf. Very rough.
Heavy: A thick, strong and coloury liquor with limited briskness.
High-Fried: Over-fired but not bakey or burnt
Lacking: Describes a neutral liquor. No body or pronounced characteristics.
Light: Lacking strength and depth of colour.
Malty: A full, bright tea with a taste of malt.
Mature: Not bitter or flat.
Metallic: A sharp Metallic taste.
Muddy: A dull liquor.
Musty: Suspicion of mold.
Plain: A liquor that is “clean” but lacking in desirable characteristics.
Pungent: Astringent with a good combination of briskness, brightness and strength.
Quality: Refers to “cup quality” and denotes a combination of the most desirable liquoring qualities.
Raw: A bitter, unpleasant flavor.
Soft: The opposite of briskness. Lacking any “live” characteristic. Caused by inefficient fermentation and/or firing.
Strength: Substance in cup.
Taint: Characteristic or taste that is foreign to tea, such as oil, garlic, etc. Often due to being stored next to other commodities with strong characteristics of their own.
Thick: Liquor with good colour and strength.
Thin An insipid light liquor that lacks desirable characteristics.

http://www.drinktea.co.uk/glossary.html

http://greatist.com/health/13-science-backed-reasons-tea-awesome