The authentic Thai sweet basil, known as Horapa, in a large-leaf selection that crops more generously than the usual narrow-leaved type. Glossy pointed leaves, purple stems and pink flower spikes, with a flavour firmly anise and liquorice where the Italian basils are sweet.
The important difference for a cook is heat stability. Italian basil should only meet a pan once the heat is off; Horapa genuinely cooks, holding its aroma through a simmering curry or a hot wok. That single quality is why it cannot be replaced with a Mediterranean basil.
Use it the way Thai cooks do, in two additions — a handful early to build the sauce, another at the end for the bright top note. And let one or two flower spikes develop per plant: the flowers carry a more concentrated aniseed flavour than the leaves and make the best garnish the plant produces.
