Chew Chong (Chau Tseung) was born in Canton (Guangzhou), China. Nothing is known of his parents except that they originated from Kaiping county, Guangdong province. His date of birth is unclear: Chong himself put it at various times between 1827 and 1844. After receiving a good education, which included English, Chong went to Singapore, where he worked in a merchant's office. Around 1856 he emigrated to Victoria, Australia, and for 11 years was a storekeeper in Castlemaine. In 1867 he left for Otago, New Zealand.
For the next three years he collected scrap metal for shipment to China, at a time when virtually every other Chinese in Otago was connected with goldmining. He made his way north in 1870 as a pedlar. In the Taranaki bush he found the Jew's ear fungus (Auricularia cornea) growing profusely on māhoe, tawa and pukatea trees, especially burnt, decaying specimens. Chong knew this fungus as a gourmet and medicinal food, and he settled in New Plymouth as a storekeeper, buying fungus for export to China and selling imported Chinese goods.
By 1872 European and Chinese merchants and traders were competing with him for the fungus. Nevertheless, Chong acquired a substantial proportion of the trade. The fungus was gathered and dried by Europeans and Māori as a source of cash, usually at 2d. to 3d. per pound; moreover, its collection by women and children allowed men to continue farm work. It was the principal cash income of many Taranaki dairy farmers since they usually bartered their butter to storekeepers. The fungus became known as 'Taranaki wool', and Taranaki as the 'fungus province'. Fungus exceeded butter in annual export value five times between 1874 and 1881, although butter exports greatly increased after that. The greatest decade of fungus collection was the 1880s. Much of the trade was trans-shipped from Sydney to the East.
Meanwhile, Chew Chong established branches of his store at Inglewood (1872) and Eltham (1882), selling the usual merchandise as well as Chinese silk and fancy goods. He was an enterprising storekeeper; for example, he sought commissions for a Chinese artist in Hong Kong who painted portraits from photographs; he sold groceries and meat cheaper than his business rivals; and his Eltham store bought large quantities of cocksfoot seed and marketed it throughout the country, thereby creating a significant source of income for local settlers.
Chew Chong spoke and wrote English fluently. He was a small, conservatively dressed man, who was shrewd but generous, kind, honest and good-humoured. He was naturalised in 1873. On 16 February 1875 at New Plymouth he married Elizabeth Whatton, the daughter of local settlers who were connected with Taranaki ironsand smelting. A quiet woman, she and Chong had 11 children, four of whom died in infancy or childhood.
Inevitably, Chew Chong became involved in butter making because of the barter system for this product. Problems arose, however, as he was 'always buying the settlers' butter, nearly two tons a week, and shipping it to England and Australia, and constantly losing money through bad butter.' Butter factories were the key to higher quality, and the first one in Taranaki opened in 1885. A creamery was erected in 1886. Chew Chong's Jubilee factory at Eltham and two other butter factories were built in 1887. Later, he added four creameries, bought the Mangatoki butter factory in 1891, and was a shareholder in the Egmont Co-operative Box Company. All were in or near Eltham, which undoubtedly owes much of its growth to him.
The Jubilee factory was awarded 'the palm among butter factories' by the government dairy inspector in 1888. By 1889 Chew Chong had installed a Hall's refrigerating machine, which was probably the first freezing machine in a New Zealand butter factory. At the New Zealand and South Seas Exhibition in Dunedin (1889–90), he won first prize for the best half-ton of butter suitable for export, and flew the Chinese flag over his exhibit. In 1891 his factory still held its reputation as being 'second to none in the colony.' He invented a rotary butter worker, an air cooler and an impressed brand for butter boxes. To ensure milk supply he not only owned a herd of cows but also introduced one of the first systems of share-milking. He sold his butter both overseas and within New Zealand.
From 1892, however, Chew Chong lost many of his milk suppliers to the co-operative dairy movement, which opened factories at Eltham, Ngaere, Cardiff and Stratford. He sold the Mangatoki factory in 1893, suffered financial losses, and his Eltham store burnt down in 1900. He closed the Jubilee factory in 1901 and retired in New Plymouth.
Yet Chew Chong retained the respect of his fellow-citizens. His civic endeavours include his donation of a flag-pole to the New Plymouth Recreation Grounds. In the severe influenza epidemic of 1891–92 he offered to travel in Taranaki to treat patients without charge. His therapy was apparently often successful, but the underlying theory of skin parasites as the infective organism brought ridicule. He was a member of the Taranaki Chamber of Commerce and a strong supporter of the province's cool storage industry, in particular the Taranaki Freezing Works Company. The Taranaki Herald treated Chinese news fairly and sympathetically, almost certainly in large measure out of respect for Chew Chong.
Although Chew Chong had broken away from the Chinese community in New Zealand, he retained a strong sense of Chinese identity. When he returned to China with a son in 1905, well-wishers presented him with a bag of sovereigns. Earlier, he was hailed as a pioneer of the butter industry, and in 1910 85 prominent citizens presented him with another purse of sovereigns and an illuminated address. This stated that he had saved 'many a family from want and penury' through his export trade in fungus, and had 'led the way' in butter manufacture in Taranaki. He died at New Plymouth on 7 October 1920, survived by his wife and six children.