What binchotan actually is
Binchotan (備長炭) is a premium Japanese 'white charcoal' — produced by carbonising hard oak (typically Ubame oak / Quercus phillyraeoides for Kishu Binchotan, Bay laurel / Litsea for Tosa Binchotan) at relatively low temperature, then finishing at 1000°C+ to achieve a dense, hard, low-impurity charcoal. The result burns at higher temperature, longer, with dramatically less smoke than standard charcoal — properties that make it the global benchmark for premium yakitori (grilled chicken skewer) restaurants.
Two GI-protected varieties: Kishu Binchotan (紀州備長炭) from Wakayama prefecture and Tosa Binchotan (土佐備長炭) from Kochi prefecture [1]. Each has slightly different flavour-imparting properties and pricing; Kishu is generally the higher-priced reference.
Sources: [1]