Ragi [rah- gi] Indonesia, Budob [boo-dob] Philippines, Chu [choo] China.
Ragi [yeast cake] is a natural-starter similar to what sourdough starter is for preparing sourdough bread. The yeast cakes are prepared from crushed raw rice pressed into flat cakes of about 2 to 3 cm in diameter by 1 cm thick. The rice cakes are wrapped in leaves and fermented for a few days at room temperature [20° C - 30°C ]. The cakes are dried for long term storage.
Ragi is used by crushing the tablets and then mixing the powder with cooked, cooled ingredients such as glutinous rice [for tape making] or cassava root [for peuyeum]. The mixture is fermented for a particular length of time, depending on the product being prepared. In general, fermentation is usually between 3 to 5 days. Apart from preparing tape and peuyeum, ragi is also used as a starter for brewing Brem [rice wine] in Indonesia. Similar yeast cakes of China [chu] are used to ferment other ingredients, including cereals, fish and legumes such as soybeans.
The important microorganisms in ragi fermentation is the mold, Amylomyces rouxii and yeast, Endomycopsis burtonii [Ko, 1972]. Of 41 yeast strains isolated from Indonesian ragi by Saono and co-workers [1977], 19 were found amylolytic [hydrolize or breaks down starch into simple sugars], none were proteolytic [breaks down protein into peptides], but 14 were lipolytic [breaks down fats]. All mold isolates were amylolytic and lipolytic, and 89% also exhibited proteolytic activity.
Further Reading