Dust
Dust is the bottom rung of the whole grading ladder, not a sign that something went wrong. It is the smallest particle size a factory sifts out on purpose, prized in exactly the markets that want the fastest, strongest cup a mesh can produce.
What it is
The finest particle size the grading system names, sifted through the tightest mesh below fannings. Several named dust grades split this tier further, by colour (Red Dust) or by a second, finer sift (Super Fine Dust), but none corresponds to a fixed, agreed particle size.
Where you meet it
In the strongest, fastest-brewing teabags and in markets that value a big, quick colour over a delicate cup. Dust grades are routinely priced and marketed as lower quality by appearance, even where the leaf underneath is not.
How to read it
Read 'dust' as the bottom of a size ladder, not a verdict on the leaf inside it. Dust teas can be of higher quality and value than whole-leaf grades, even though most buyers judge tea by appearance alone.
A common mistake
Assuming dust means low-quality tea, or literal sweepings. It is a named particle-size grade like every other rung on the ladder, and grading terminology tracks size and manufacturing method, never quality, whichever tier it names.
Sources
- dust teas may be of higher quality and value than whole-leaf grades, although the consumer tends to judge by appearance. Willson & Clifford, eds., Tea: Cultivation to Consumption (Chapman & Hall, 1992)
- there is no international standard for particle size in a grade, and grade names are an approximate indication of leaf size and manufacturing method. Willson & Clifford, eds., Tea: Cultivation to Consumption (Chapman & Hall, 1992)