The working answer
Tea is a dry, shelf-stable product, so the honest date is a best-before - a statement about how long quality holds - not a use-by, which belongs to perishable safety law. A defensible best-before rests on four inputs: how the format actually behaves over time, what the packaging barrier holds out, the storage conditions across warehouse and transit, and the destination market's wording and format rules. It is set per program against those inputs, with retain samples and sensory checks behind it. What a date should never be is the one thing it too often is: a number copied from a competitor's pack. That is the only kind of date that cannot be defended when a retailer's QA team, a marketplace auditor, or a customer finally asks what it rests on.
Best-before versus use-by, in one paragraph
The two phrases are not interchangeable, and the difference is legal, not stylistic. A use-by date is a safety threshold for foods that become unsafe with time; dry tea in sealed packaging is not that kind of product - kept dry and sealed it remains safe far beyond anyone's interest in drinking it, and what fades is the cup, not the safety. A best-before date says quality is expected to hold to this point under stated conditions, which is exactly the promise tea can make honestly. Because the wording is regulated - which phrase applies, and how it is written, varies by market - the desk prints dates only in the destination's expected form, and never attaches safety language to a product family that does not carry it. Getting this right is one decision, made once, per market.
The inputs that move the date
Format behavior comes first. Pan-fired greens are the aristocrats of the shelf: magnificent young, quietly fading first, their aroma flattening long before anything is wrong. Roasted blacks and rock oolongs are the opposite temperament - stable, and often better after months of rest that lets the fired edge settle. White teas move slowly; aged white programs move deliberately, dated around an intended trajectory rather than a fade. Puer, especially cake formats, is an aging product whose dating conventions differ by style and market. Herbal and fruit blends have no oxidation to manage but two honest weaknesses: top-note aromatics depart early, and open handling invites moisture. The second input is packaging: foil laminate bags inside cartons are the default, and the nitrogen flush option exists precisely to push the aromatic formats' horizons out - the mechanics are in the nitrogen flushing note. The third is storage discipline: cool, dry, dark, and away from odor, from the packing floor to your warehouse, in transit as on the shelf.
A working basis by format
| Format | Quality behavior | Dating basis |
|---|---|---|
| Pan-fired greens | Aroma fades first; everything else follows later | Tighter horizon; foil barrier and nitrogen flush support it |
| Roasted blacks and rock oolongs | Stable; often improve with a rest | Longer horizon grounded in the format's known behavior |
| White teas | Slow change; aged lines move by design | Per-program basis with stated intent |
| Puer cakes | Aging product; trajectory is the point | Conventions differ by market and style; confirmed per program |
| Herbal and fruit blends | Aromatics depart first; moisture is the risk | Packaging barrier plus warehouse discipline |
Notice what the table does not contain: a column of years. The honest answer to "how long is tea good for" is "longer than the format's aroma, under the conditions stated" - and the conditions are the part a program controls and documents.
The verification loop behind the date
A date becomes defensible the same way any quality statement does: evidence, kept. This desk retains samples per batch, so the tea in your warehouse can be compared against its own past at any point. The check is sensory and structured - the five factors of dry leaf, liquor, aroma, taste and wet leaf, evaluated against the retained reference under the same protocol used at approval. When a program runs across seasons, those periodic checks are what turn "the date says so" into "the cup says so", and they are also the early-warning system: a green program whose nine-month check shows flattening aroma has learned something actionable about its packaging or its horizon before customers learn it. Rotation is the quiet partner of verification. A dating basis assumes the pack is consumed in roughly the order it was packed, which is why lot codes earn their place on the pack: first-packed, first-shipped, first-displayed. Retail partners read clear lot coding as a sign the program expects to be checked, and they handle dated stock accordingly - the small courtesies of traceability tend to return as shelf-side cooperation. The storage half of the discipline - what warehouses and shelves must and must not do - is laid out in the grading and storage guide, and the seasonal behavior of greens specifically in the green tea shelf-life note.
Wording, placement and market rules
The final input is the destination's own rules: which phrase is expected, in what date format, placed where, and alongside what lot code for traceability. Formats differ enough that date artwork is confirmed per market rather than assumed, and the lot code's adjacency to the date is not decoration - it is what makes the date traceable to a batch with retain samples behind it. The placement conventions sit among the other mandatory elements described in the labeling basics note. Programs aged by design - puer, aged whites - get one extra review, because some markets have specific conventions for products whose quality improves with time; the puer storage note covers the aging side. Pack formats and barriers for each horizon are on the packaging options page, and transit conditions on the logistics page.
To set a dating basis for a new program, state the formats and destination on the quote form; the proposed basis - format behavior, barrier, storage terms - arrives with the sample plan, before the artwork is drafted.