The secret behind Seolleim Coolish's icy crunch

"If Seolleim is about smoothness, Coolish is all about the satisfying crunch and refreshing chill that only real ice can deliver. We control the ice particle size with precision to match consumer preferences."

On Thursday, a reporter visited the ice cream production building at Lotte Wellfood's Yangsan factory in South Gyeongsang Province. Outside temperatures exceeded 30 degrees Celsius, but the factory floor was cool. The facility produces some of Lotte Wellfood's most recognizable frozen treats, including Seolleim, Subakba and Joseubar.

Past a production line fragrant with the sweet scent of Subakba, a large cylindrical machine came into view — the icemaker, the heart of Seolleim Coolish production. Seolleim Coolish is the Korean adaptation of Coolish, the best-selling ice cream brand of Lotte Japan. While the original Seolleim is a smooth milkshake-type product, Seolleim Coolish adds fine ice particles for a sharper, more refreshing bite.

To differentiate the product through its signature texture, Lotte Wellfood invested 1.45 billion won ($933,000) in the icemaker. Previously, the factory crushed commercially purchased block ice, but the new machine produces fine ice particles directly from purified water. "By making ice particles of the exact size we want from purified water, we raised both hygiene and quality standards — and eliminating the heavy lifting involved in moving block ice has also reduced the risk of workplace accidents," said Choi Myeong-wan, plant manager of Lotte Wellfood's Yangsan factory. The factory now produces an average of 19.8 metric tons of ice per day during summer, cutting annual ice procurement costs by 150 million won.

Ice mixing takes place in two stages. The icemaker first produces relatively large particles of about 5 millimeters, which travel through chilled pipes to a second process where they are broken down further. The pipes were so cold that white vapor rose from them. The ice used in Coolish is kept at minus 0.5 degrees Celsius — cold enough to prevent the particles from clumping together, so the product retains its crunchy texture and refreshing chill even after extended storage.

The finished mixture moves to a filling machine that loads eight pouches simultaneously. Air is injected through a hose, the contents are filled, and the caps are sealed — all in a matter of seconds. Workers pull pouches off the line to check their weight and verify that production meets specifications.

The filled pouches then undergo rapid freezing for about 30 minutes in a tunnel kept at minus 37 degrees Celsius. Packaging is fully automated: six robots sort Seolleim and Coolish pouches and pack them into boxes at high speed. The line turns out 140 Coolish pouches per minute and 190 Seolleim pouches per minute — the fastest pouch ice cream production line in South Korea.

Seolleim Coolish is a flagship example of the "One Lotte" strategy championed by Lotte Group Chairman Shin Dong-bin. It is the first frozen dessert to combine a leading Lotte Japan ice cream brand with domestic production capabilities and adapt it for the Korean market. Its share of Seolleim brand sales reached 24 percent in June. Lotte Wellfood plans to grow the Seolleim brand from its current scale of about 35 billion won to 55 billion won by 2030.

In May, the company applied micro-foam technology to the Seolleim packaging to address the problem of cold hands. An air layer is created between the inner and outer pouch walls and filled with nitrogen, reducing the direct transfer of cold to the hand. The product's opening was also widened by 11 percent compared with the previous design, making the contents easier to consume.

Yoon Jeong-eun, a senior manager in the ice cream marketing division, said the company would "sharpen brand competitiveness by focusing the original Seolleim on the winter season and Seolleim Coolish on summer," adding that it would expand consumer touchpoints by signing broadcaster and webtoon artist Kian84 as a brand model and running a range of marketing campaigns, including 'Seolleim Run.'"