Dærst

According to the Old English Dictionary:

es;

dærst

m. Leaven; fermentum :-- Ongelíc is dærste simile est fermento, Lk. Lind. War. 13, 21. Rush. has dat. pl. Gelíc is dærstum, Lk. Rush. War. 13, 21: 12, 1: 22, 1. DER. ge-dærsted. dærstan,dærst