AG Barr is to launch a new Rockstar range of energy drinks to cash in on the craze for old-school flavours.

Rockstar Twister will land in chillers from 1 January in Smashed Blue Raspberry and Wacked Red Berry (pmp: 99p/500ml). The two variants would tap “the current trend for retro flavours, offering a full flavour hit at only 25 calories per 100ml” said the soft drinks maker. Caffeine is 32mg per 100ml.

Twister is the second Rockstar extension in recent months, as AG Barr works to broaden the appeal of an energy brand up 9.4% in value sales to £53.6m on volumes up 10.2% [Nielsen 52 w/e 8 September 2018].

In August, the supplier added the 500ml Rockstar First Start – a low-cal lineup designed specifically for starting the day. Made with real fruit juice, the two variants, Mixed Berries and Orange Clementine, contain no more than six kcals per 100ml, while caffeine content is 32mg per 100ml – roughly equivalent to a 250ml cup of coffee.

Since its launch, First Start had sold 3.9 million units, according to Adrian Troy, marketing director at Barr Soft Drinks.

The introduction of Twister would “kickstart energy drinks innovation for 2019, offering the great-tasting, full-flavour energy boost that shoppers have come to expect from Rockstar” he added.