Dr Olmo developed Ruby Cabernet to supply the Californian wine industry with a variety that was able to thrive under the hot climatic conditions where Cabernet Sauvignon struggled.
Ruby Cabernet, as such, was developed to produce the quality characteristics of Cabernet Sauvignon and the hardiness of Carignan. The variety was commercially released in 1948 and became very popular in the 1960s.
While the variety performs well under warm climatic conditions, better quality single varietal wines are associated with grapes produced in cooler regions.
The variety was first planted in South Africa in 1982 and the area under production has since reached over 2 000 ha. The variety is produced in all the wine producing regions of South Africa, with Robertson and the Breedekloof having the biggest areas under production.
It is a vigorous grower with the ability to produce up to four times more per hectare than Cabernet Sauvignon. Production averages between 20 t/ha to 30 t/ha. It is well suited to mechanical harvesting, especially when planted over a large area. Berries ripen late midseason, from the second half of March.
The variety produces small oval berries that turn a dark blue black colour when fully ripe. The skin is thick, while the flesh is watery with slight grassy flavours. Leaves are large, dark green, shiny and three to five lobed.