Hoat-kàⁿ (發酵; fermentation) it-poaⁿ sī teh kóng seng-bu̍t-thé tùi iú-ki-bu̍t ê bó͘-chióng hoà-ha̍k hun-kái kòe-têng. Hoat-kàⁿ sī jîn-lūi siāng-chá chiap-chhiok tio̍h ê seng-bu̍t hoà-ha̍k hoán-èng. Hiān-chāi, hoat-kàⁿ tī si̍t-phín kang-gia̍p, seng-bu̍t kap hoà-ha̍k kang-gia̍p í-keng pī kóng-hoat ê lâi èng-iōng. Hoat-kàⁿ ē-sái kóng sī seng-bu̍t hoà-ha̍k ê ki-pún kòe-têng, iā chiū sī hoat-kàⁿ kang-têng. Tùi hoat-kàⁿ hoán-èng ki-chè ê gián-kiù iu-goân tng-teh chìn-hêng.

Chiú-cheng hoat-kàⁿ ê kòe-têng