The Isabella grape

Grape

A grape is a non-climacteric fruit, specifically a berry, that grows on the perennial and deciduous woody vines of the genus Vitis. Grapes can be eaten raw or they can be used for making jam, juice, jelly, vinegar, wine, grape seed extracts, raisins, molasses and grape seed oil. Grapes are also...

 is a cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

 derived from the grape species Vitis labrusca

Vitis labrusca

Vitis labrusca is a species of grapevines belonging to the Vitis genus in the flowering plant family Vitaceae. The vines are native to the eastern United States and are the source of many grape cultivars, including Catawba and Concord grapes, and many hybrid grape varieties such as Agawam,...

or 'fox grape' which is used for table, juice and wine production.
The skin of Isabella when ripened is a dark purple, almost black with a tender green-yellow flesh. It has large well formed fruit clusters with thick bloom. It is a slip skin variety, meaning that the skin separates easily from the fruit. The grapes are used to make wine, most notably Uhudler

Uhudler

Uhudler is a unique wine from Austria, which originates in the Südburgenland region . In appearance it is often a rosé colour, but is also made as a white wine. It has intense flavours of strawberry and black currants, a characteristic taste often called "foxy" in wine parlance...

 and Fragolino.