It doesn't drip. That was the trick.
Merong Bar — 메롱바, named for the childhood taunt of sticking out your tongue — is a tongue-shaped ice cream that, instead of melting into a puddle, sags into a quivering knot of jelly. Last September, that one quirk made it the most talked-about dessert in South Korea.
Introduced by the convenience-store chain GS25 in early September, the bar sold about 800,000 units in two weeks and cleared five million within two months, shoving aside the longtime best sellers Worldcone and Melona to become the fastest-selling ice cream in the chain's history. From Sept. 11 to Nov. 11, GS25's bar-type ice cream sales more than doubled and its overall ice-cream sales rose about 60 percent. A strawberry sequel reached No. 2 in a week; rivals CU and Seven-Eleven scrambled to stock it. Review clips drew millions of views, and shoppers — half-exasperated, wholly hooked — took to checking store apps for stock before bothering to go.
Then someone read the ingredients.
The Chinese-made bar, journalists and consumers soon established, owes its colors to synthetic "tar dyes," coal- and petroleum-derived additives that regulators abroad treat with suspicion. Korea's food-safety database lists Yellow No. 4 and Blue No. 1 in the original bar; the strawberry version adds Red No. 40. The European Union flags Yellow No. 4 as a possible asthma trigger and restricts Blue No. 1 over concerns about hyperactivity in children, and Britain and the bloc require labels warning that such dyes may affect children's attention and activity. In the United States, regulators announced in April 2025 a plan to phase out six petroleum-based dyes, Blue No. 1 among them.
None of it slowed sales. The bar still fills freezers in supermarkets and convenience stores nationwide, though how many have sold since the controversy broke is anyone's guess.
South Korea's Ministry of Food and Drug Safety insists the dyes are legal and safe within daily-intake limits. Even so, it will open a reassessment of the country's color-additive standards in January — a review it runs every five years, last completed in 2019. Under current rules, just two dyes, Red No. 2 and Red No. 102, are barred from children's food, out of nine tar dyes permitted overall. The science is unsettled, varying by dye and by study; Jang Hong-je, a chemistry professor at Kwangwoon University, urged perspective over alarm, noting that while only some research points to sensitivity reactions, "there is no absolute safety."
These are associations studied in some human and animal research, not proven cause and effect. EFSA and JECFA permit the dyes within acceptable daily-intake limits; the EU's main measure is warning labels, not a ban.
Nor is the problem confined to one ice cream. In October, Representative Park Hee-seung of the Democratic Party said a survey of 103 jellies sold near elementary schools and online turned up tar dyes in 73 of them — roughly 70 percent — averaging 2.5 dyes apiece; two were imports tinted with additives Korea does not even approve.
None of this was hidden.
Every dye now under review was printed on the wrapper from the first day of the frenzy. It took five million bars — and a generation of children with candy-colored tongues — before anyone thought to turn the package over and read it.