Nestlé will launch a ruby chocolate version of its KitKat brand in Japan and South Korea this month, becoming the first consumer brand to market the new chocolate variety developed by Barry Callebaut.

The move in Japan, one of KitKat’s most important markets, is part of a wider effort by the world’s largest packaged food company to push its confectionery creations upmarket with special innovations.

The announcement comes two days after Nestlé agreed to sell its US confectionery unit, which does not include KitKat, to Italy’s Ferrero, underlining its commitment to the non-US business.

“KitKat Chocolatory Sublime Ruby will be available from today, in time for Valentine’s Day,” Barry Callebaut said in a statement, adding the product would also be available online.

Barry Callebaut unveiled the ruby variety in September, creating a fourth kind of chocolate in addition to dark, milk and white. After more than 10 years of development, it is the first new kind of chocolate in decades.

It said ruby chocolate used in KitKat “has a fresh berry-fruity taste and characteristic colour”.

Ruby chocolate is made from the ruby cocoa bean. No berries, berry flavour or colour are added.

There are already hundreds of KitKat products in Japan, including green tea and strawberry flavours, and a luxury version topped with nuts and dried fruit.