Hickory nuts

Hickory nuts

　　A treasure of Lin’an County, according to the 1983 forestry resources survey, the county had 162,949 mu of mature hickory forests, which have now expanded to 257,800 mu. Historically, the original Changhua County area produced the most and best quality, hence the name Changhua hickory nuts. They are mainly distributed in towns such as Daoshi, Xinqiao, Yu’tiao, Shunxi, Jiekou, Maxiao, Tuankou, Longgang, Shirui, and Henglu. Smaller areas can also be found in towns like Taiyang, Xitianmu, Dongtianmu, Yangling, Linmu, and Qingyun. Hickory nuts belong to the Juglandaceae family, genus Carya, and are grown in soils formed from the weathering of limestone—such as yellowish oily clay, black calcareous soil, and calcareous shale. The trees typically begin bearing fruit between 10–15 years, though (through years of research by local forestry scientists, grafting techniques have been used to shorten this period to five years, creating favorable conditions for boosting hickory nut production). Trees reach full production at around 25 years and can live for 60–70 years, even up to 100 years. The nuts mature around the time of White Dew each year and are subject to alternate bumper and lean years. The fruit is round with a very thick shell, ridged wings, and a yellowish-brown exterior. After removing the outer shell using a husking tool, the inner nut—a spherical kernel that is slightly pointed at one end—appears pale yellow-white with fine wood grain. The nuts are sorted by floating them in water (the ripe ones sink), then boiled, turning them brownish-black or dark brown. Once dried, they become “light hickory nuts,” i.e., the final product. Hickory nuts are high in oil content; the clean kernels contain 69.8–74% oil, while the in-shell nuts yield about 28% oil. In addition to rich plant oils, the kernels are 18.3% protein and contain a variety of vitamins, offering medicinal benefits such as lubricating the intestines, nourishing the body, and anti-aging properties. The ash from burnt shells contains 20–30% alkali, with over 60% being potassium carbonate, making it useful for chemical, pharmaceutical, and light industrial applications.

　　( Lin’an )