The short answer: it refers to when the leaves were picked
Tea plants can be harvested more than once in a year. “First harvest” generally means the first picking of that year’s new growth. In Japanese tea terminology, this is commonly called ichibancha, or first-picked tea. The exact timing depends on the region and local growing conditions, so it does not happen everywhere on one fixed date. (nihon-cha.or.jp)
For matcha, the harvested leaves are made into tencha: they are steamed and dried without rolling, then ground into a fine powder. In other words, “first harvest” describes the timing of the leaves’ picking—not a separate way of making matcha. (nihon-cha.or.jp)
First harvest, first flush, and tencha
You may see “first harvest” used alongside “first flush” or “ichibancha.” These terms commonly point to the first picking of the season. Japan’s Ministry of Agriculture describes Uji tea’s first-picked leaves as spring buds, and notes that tencha is among the teas made from them. The season and picking dates vary by place, however, so this example should not be treated as a calendar for every tea-growing region. (maff.go.jp)
Harvest timing is only one part of the story. Tencha is also distinguished by how it is grown and processed. Japanese tea-industry guidance describes tencha as leaves grown under cover before picking, steamed, and dried without rolling; matcha is made by grinding tencha into fine powder. (nihon-cha.or.jp)
What the label does—and does not—tell you
A “first harvest” label can tell you that the maker or seller identifies the tea as coming from the year’s first picking. On its own, it does not specify the cultivar, growing location, length of shading, processing details, blending, or how the finished tea tastes.
It also should not be read as a universal grade. The Japan Tea Association’s terminology document says that first-, second-, and later-tea-season categories follow the customary production-time divisions of each municipality. That is a reminder that season labels can depend on local practice. A harvest label alone does not establish a single, internationally uniform quality tier. (nihon-cha.or.jp)
The International Organization for Standardization’s matcha report describes matcha in relation to its plant source, cultivation, and production methods. Its public summary does not define “first harvest” as a matcha grade. So it is more useful to treat the phrase as harvest information than as proof that one product must be better than another. (iso.org)
Why first-harvest matcha may cost more
Some first-harvest teas may be priced higher because of factors such as the leaves selected, growing and processing choices, supply, and the producer’s intended style. But the words “first harvest” alone cannot explain a particular price or confirm that a matcha will suit your preferences. Compare the full product information rather than relying on the phrase as a quality guarantee.
A practical way to read the claim
When a package says “first harvest,” look for details that clarify what the maker means: the harvest year or season, region, whether the tea is made from tencha, and any information about cultivar, shading, or blending. If those details are not provided, the phrase may still indicate a first picking, but it leaves more unanswered.
Harvest timing is one useful detail among several. Compare it with the product’s origin, freshness information, intended use, and the preparation style you actually enjoy.