Mahewu is a traditional cool non-alcoholic fermented beverage known among African countries; generally made from cereals but also it can be made from tubes. The raw material (cereals and tubes) is spontaneity fermented at room temperature by acid lactic bacteria, the fermentation process is considered to increase the nutritional content of mahewu. The beverage is most known in the liquid form, that takes up more volume and less shelf life. The presentation of mahewu in powder it will allow minor volume and increase the shelf life. The objective of the present study was to develop cassava mahewu in powder form in order to stabilize a protocol of rehydration and investigate its instantaneous behavior. The standard cassava mahewu was prepared using fermentation techniques and thereafter 30 g and 40 g were firstly frozen for 24 h/-18°C followed by freeze drying at -20°C for a period of 24 h to obtain the powder form of cassava mahewu. The pH and acidity levels were controlled throughout the preparation processes and the total solids content of the solution was adjusted to 15.9 ± 0.1 ºBrix, in order to freeze dry with a quantity of known soluble solids. The moisture content, water activity (w a ), tests of instantaneousness (wettability and dispensability) of the powdered cassava mahewu and the sensorial properties of the reconstituted powder after rehydration with water at 25°C to replace 60%, 80% and 100% of water lost during the freezedrying were evaluated using standard methods. The results showed a reduction of the pH (6.11 to 4.56) and an increased in acidity (0.06 g/100g to 0.25 g/100g of lactic acid) of the standard cassava mahewu at beginning (t = 0 h) and at end of fermentation (t = 24 h) respectively. Both samples of 30 g and 40 g indicated a water activity of 0.39 and 0.42, moisture content of 6.50 and 8.57% and instantaneousness of 3 s and 3.33s respectively. The results showed an optimal behavior of instantaneousness of 3 s indicating an easy penetration of liquid (water) on the powdered cassava mahewu. According to the sensorial analysis, the reconstituted cassava mahewu rehydrated with 100% of water lost during the freeze drying was more appreciated and preferred compared with 80% and 60%.