A mooncake is a Chinese bakery product traditionally eaten during the Mid-Autumn Festival. The festival is for lunar worship and moon watching, when mooncakes are regarded as an indispensable delicacy. Mooncakes are offered between friends or on family gatherings while celebrating the festival. The Mid-Autumn Festival is one of the four most important Chinese festivals.
Typical mooncakes are round pastries, measuring about 10 cm in diameter and 3–4 cm thick. This is the Cantonese mooncake, eaten in Southern China in Guangdong, Hong Kong, and Macau. A rich thick filling usually made from red bean or lotus seed paste is surrounded by a thin (2–3 mm) crust and may contain yolks from salted duck eggs. Mooncakes are usually eaten in small wedges accompanied by Chinese tea. Today, it is customary for businessmen and families to present them to their clients or relatives as presents, helping to fuel a demand for high-end mooncake styles. The energy content of a mooncake is approximately 1,000 calories or 4,200 kilojoules (for a cake measuring 10 cm (3.9 in)), but energy content varies with filling and size. There is also considerable waste. According to the Wall Street Journal's China edition, as many as two million mooncakes are thrown away each year in Hong Kong alone.