The brewer is backing the move with a £1 million ad campaign promoting Cold You Can See in July, and has also produced POS kits.
Carling customer marketing director Tom Feinson said: "Until now, thermochromic was only available on aluminium cans. However, we've persevered with this and pioneered a new ink that will turn blue when your Carling is cold enough to drink. With thermochromic, we are rewriting the rules of cold. No longer are the measurements of cold touch and taste alone ."
The thermochromic indicator is a picture of a can which turns blue when the beer is cold enough to drink. A blue flash at the top of each can tells customers to look out for the indicator.
Feinson added: "We are adding value back into the category. Consumers measure value by quality and the key quality signal for lager is coldness. Our research shows that 86 per cent of consumers think it's important to drink cold beer and that they are prepared to pay for it."
Beer in brief
Magners is back on TV screens with a summer campaign showing lazy summer evenings in the apple orchard and by a waterside pub to the soundtrack of Donovan's Sunshine Superman. Outdoor posters of Magners' pint bottle, glass and ice will feature the strapline Time To Cool Down.
Budweiser has renewed its partnership with the football Premier League until 2010. The deal has been extended to cover all Anheuser-Busch brands, with the main focus in the UK on Budweiser.
Coors has given its 3.7 per cent sparkling ale Stones a new look and will run a Father's Day ad campaign in the beer's Yorkshire heartland.
The Campaign for Real Ale's Scottish Traditional Beer Festival, which takes place in Edinburgh's Assembly Rooms from June 14-16, is giving visitors the chance to try beer styles unique to Scotland, including a range of traditional shilling ales.
St Helier pear cider has launched a 1-litre bottle (rrp £2.99) after sales of its 50cl package (rrp £1.69) outstripped all its expectations. Joint managing director Paul Burton said the new size is aimed at people who want to share the cider with a meal or take it to a party. Both sizes are now available in amber glass.
Fuller's London Pride is the official beer of the London Senior Masters golf tournament, which will be held at the London Golf Club from June 22-24, with highlights being shown on Sky TV.
Adnams is to raise its profile in its East Anglia homeland with a series of appearances at summer events, including the Suffolk Show, Latitude and the Norwich Food Festival.