As a rule, grape berries have four to five (rarely six) seeds. Seedless or seedless berries are an important quality criterion for table gra pes, which is why varieties with this characteristic are bred. Completely seedless berries are a freak of nature due to various environmental conditions. The phenomenon occurs mainly as a consequence of parthenocarpy (virgin fruit), i.e. fruit development without prior fertilisation. Strictly speaking, however, these grapes do not have exclusively seedless but seedless berries. These are also not noticed at all when eaten due to their softness. The number, size and quality of the grapes depends not only on hereditary disposition but also on the temperature during growth.
For me, Lexicon from wein.plus is the most comprehensive and best source of information about wine currently available.
Egon Mark
Diplom-Sommelier, Weinakademiker und Weinberater, Volders (Österreich)