When Japan Fell in Love with Portuguese Sweets

Some love stories are grand, others are unexpected. The tale of how Japan fell for Portuguese sweets is somewhere in between—a romance sparked by chance, fuelled by sugar, and lasting far longer than anyone expected.

It all began in the 16th century, when Portuguese sailors and missionaries turned up on Japanese shores with their curious cargo of Catholicism, firearms, and an unholy amount of sugar. The Japanese had seen foreign traders before, but the Portuguese were something else. They spoke a strange language, dressed like no one had ever seen, and most intriguingly, they carried sweets that were unlike anything Japan had tasted before. These were not the subtle, elegant confections the Japanese were used to—these were rich, bold, and unapologetically sweet.

At the time, sugar was a rare and precious commodity in Japan, reserved for the elite and used sparingly. Enter the Portuguese, who seemed to believe that no food was complete without a liberal dose of it. Their confections—rich, eggy, and overwhelmingly sweet—were an instant sensation among the Japanese aristocracy. Sweets like castella, a fluffy, golden sponge cake, and konpeitō, tiny, jewel-like sugar candies, became symbols of exotic luxury. The Japanese, already masters of aesthetics, admired not just the taste but the craftsmanship of these new sweets. Konpeitō, with its delicate star-like shape, was particularly fascinating, and over time it became a favourite among nobility.

The Japanese, known for their precision and artistry, did not merely adopt these sweets—they refined them. Castella, originally a European sponge cake, was transformed into something uniquely Japanese: lighter, airier, and baked with meticulous care. The baking process was adjusted, the ingredients fine-tuned, until what emerged was a distinctly Nagasaki creation, subtly different from its Iberian ancestor. Konpeitō, once a novelty, became a mainstay in Japanese culture, so beloved that it eventually found its way into imperial gift-giving traditions. It was no longer just a sweet—it was a delicacy with cultural weight, reserved for special occasions and presented with the kind of reverence usually given to fine tea.

There was also nanban-gashi, also inspired by Portuguese sweets, named after the “southern barbarians” (as the Japanese affectionately called their Iberian visitors). These sweets, often made with sugar, eggs, and wheat flour, introduced a richness previously unseen in Japanese desserts, which until then had been based on more subdued flavours like red bean paste and mochi. The Japanese palate, once accustomed to the earthy and delicate, now found itself indulging in the rich and decadent. It was a meeting of two worlds, a fusion of culinary philosophies that would leave a lasting mark.

Then came the inevitable cultural clash. The Portuguese were enthusiastic missionaries, eager to convert Japan to Christianity. The sweets certainly helped—they were a persuasive tool in winning over feudal lords and influential figures. A beautifully wrapped box of konpeitō was more than just a treat—it was an offering, a diplomatic gesture, a way to open doors. But the shogunate was not amused. By the late 16th century, Christianity was seen as a threat, missionaries were expelled, and Japan entered its long period of isolation. The Portuguese were sent packing, their churches destroyed, their presence erased. But their sweets? Those were too good to get rid of.

Long after the last missionary left, castella was still being baked in Nagasaki, konpeitō was still glittering in candy jars, and Japanese confectioners were still perfecting recipes inspired by their one-time foreign guests. The recipes evolved, blending with Japanese techniques, becoming something that felt native despite their foreign origins. Over the centuries, these once-exotic treats became so ingrained in Japanese culture that their origins were almost forgotten. Few people eating castella today would think of Portugal. Fewer still would associate konpeitō with missionaries. The sweets had outlasted the evangelists.

And then, history repeated itself. When Japan reopened to the world in the 19th century, foreign sweets once again arrived on its shores. But this time, Japan was not the curious newcomer—it was the master of adaptation. European-style bakeries sprang up in Tokyo and Kyoto, but the flavours were distinctly Japanese. Castella found itself sitting alongside French pastries in elegant cafés. Konpeitō, once a foreign marvel, became a nostalgic childhood treat, sold in charming paper boxes and treasured for its delicate crunch.

Even today, the echoes of that first encounter remain. In Nagasaki, castella is still made using time-honoured techniques, sometimes baked in wooden moulds, sometimes flavoured with honey or brown sugar. Artisanal konpeitō makers still carefully craft each tiny, spiky candy by hand, a process that takes up to two weeks of constant rolling and coating with syrup. The attention to detail, the commitment to perfection—these are not just sweets, they are edible history.

The influence of Portuguese sweets goes beyond castella and konpeitō. Even Japanese yōgashi (Western-style sweets) owe something to that first wave of foreign confections. The Japanese knack for blending European techniques with their own meticulous craftsmanship can be traced back to those early encounters. Today, pâtisseries in Japan produce some of the finest French and Italian pastries in the world, but there is always a subtle Japanese twist—a touch of matcha here, a refined sweetness there, an elegance that makes them unmistakably Japanese.

A slice of castella with a cup of green tea feels as naturally Japanese as a bowl of ramen. Konpeitō, now wrapped in elegant packaging, is gifted as a sign of good fortune. The Portuguese may have left, but their sugar-dusted legacy remains, a sweet reminder of a time when two very different worlds collided and found common ground—over dessert. What started as an encounter between explorers and an isolated nation became a cultural imprint that never faded. And somewhere in Nagasaki, a baker still whisks eggs and sugar together, carrying on a tradition that began with sailors and missionaries who just wanted to share something sweet.