The boiling and drying methods are further divided into methods exemplified by Boshu seiho (method of boiling and drying raw algae) in which raw algae is boiled and dried, and methods in which dried algae is rehydrated and then boiled and dried.
煮乾法ではさらに、房州製法に代表される生原藻を煮乾する方法と、乾燥原藻を水戻しして煮乾する製法とに分かれる。