Butterfly Pastry

The palmier is generally attributed to early twentieth-century France, with some scholars pointing to Viennese pâtisserie or even earlier Middle Eastern layered-pastry traditions as precedents. The route into Shanghai was indirect: baker Yang Guanlin spent years in Harbin making bread for the Russian émigré community there and absorbed Russian and French pastry techniques. In 1936 he returned to Shanghai and founded the Fuli Bread Factory — later renamed the Harbin Food Factory (Ha Shi) after the city where he had trained. Yang's workshop adapted the French palmier to Shanghai taste, pairing the caramelised sugar glaze with locally preferred butter-rich dough. The International Hotel's Fansheng Western Bakery and the century-old Der Tai Food Shop developed their own formulas alongside Ha Shi, together establishing the pastry as a pillar of Shanghai's Western-bakery culture. Since 2017, Shanghai has hosted an annual butterfly-pastry skills competition; the pastry is now widely regarded as part of the city's intangible culinary heritage.

The caramel crust fractures with an audible snap — a clean, bright crack that announces the high sugar content. Dozens of paper-thin pastry layers then separate from the inside out: the outermost are dry and crumbly, the innermost retain a faint elasticity from the butter-enriched dough. A long, warm finish of caramelised brown sugar and cultured butter lingers well past the last crumb.

Puff-pastry lamination folds a block of cold butter into dough through a sequence of rolls and letter-folds — typically four to six turns — creating hundreds to thousands of alternating layers of dough and fat. In the oven at around 200°C, the water in each dough layer (roughly 30% by weight) vaporizes rapidly, inflating the space between layers; the fat barriers melt but prevent adjacent dough sheets from fusing, so each layer puffs independently. The sugar coating caramelizes above approximately 160°C while undergoing simultaneous Maillard browning, forming the hard amber glaze and the characteristic bittersweet toffee-like aromatics that distinguish a palmier from plain puff pastry.