Shoppers are only just realising what the unusual symbol on their pack of Lurpak butter means – and the truth really is surprising.

For over a century, Lurpak fans have tucked into the Danish spread on toast, in sandwiches and melting into a crumpet, but many have never stopped to examine what the strange symbols on the underside of the brand’s trademark silver foil really mean.

One person took to Reddit’s Ask UK forum today – and their mind was suitably blown.

u/tessyxx asked: “What does this sign on the butter represent?,” along with a picture of the symbols, which look a bit like shower heads, printed on the Lurpak packaging.

u/joinmypestocult replied: “I believe the Lurmark is a trademark for quality Danish butter. The Lurmark and Lurpak are owned by the Danish Dairy Board and the quality controls are still used today.

“The lur is a type of horn, a bronze age musical instrument, and you can see four of them intertwined in the mark there, and they also appear in the Lurpak logo.”

u/another_online_idiot added: “I thought they looked like strange shower heads. Your explanation makes sense though.”

u/flaramon said: “Lurpak/Lurmark branding is based on the musical instrument, the Lur. The Lur is essentially a very long blowing horn that is traditionally curved to make them easier to carry, whilst also leaving them able to raise the instrument above the crowd (and avoid blasting into people’s faces).

u/lowflyingmissile did indeed only just realise, as they said: “Well, TIL [today I learned].”

Lurpak itself offers up an explanation for its unusual packaging symbols which matches up with Redditors. It says that the Lurmark is an officially registered trademark which it has owned since 1901, and from 1911, the company has conducted continual blind taste tests to ‘ensure the best quality’.

It said: “​On the 23rd October 1901 the ‘Lurmark’ became a registered trademark to protect from imitations and became an official quality stamp.

“From 1911, we have been conducting regular blind tastings and continuous sampling to ensure that only the best quality Danish dairies producing the best quality butter from Danish milk can use the Lurmark, a level of control that ensures even today that you only enjoy the best butter possible. With its famous entwined “lurs” horns, – Bronze Age musical instruments – the mark continues to identify the premium unique Lurpak butter that you love today. ​​Good food deserves nothing less.​”

Perhaps that helps explain why it costs £10 per Kg at Tesco and Sainsbury’s for a standard 400g tub.