Improvement of Traditional Tella Fermentation Process towards the standards in Commercial Beer Production Method

Abstract

Tella, a dense, light yellow to dark brown colored alcoholic beverage (pH 4-5; ethanol content 2-8% (v/v)), is a local beverage or traditional beverage to Ethiopia. Tella brewing process is traditional and only a household art, just like other traditional fermented foods and beverages in Africa. Besides its importance, tella gets easily spoiled or the quality of the product decreased within short period of time and causes tremendous economic loss to brewers and its fermentation process takes relatively long time (7-15 days) consisting of four easily modifiable phases. Due to those reasons, brewers brew the amount of tella must be small to sold/consumed within a short period of time. The main objective of this study is to improve traditional tella fermentation process towards the standards in with commercial beer production method. In this process, the cereal grain of barley is manually sorted to remove broken kernels and debris and then used for malting. After that, the grains selected for malting is steeped in distilled water at 25 °C for 24 h. The grains are germinated at 30 °C for 4 days and then kilined by sun drying for 3 days. The shoots and rootlets are removed manually and the malt kernels are ground in a grinding mill. In most parameters the result shows that the sample of tella without kitta (GAX and EBA) and tella without enkuro (GAX and EBA) with starter culture are more potential or effective strain than traditional method and a little bit modified method of tella samples with a wild type of yeast which reduce duration of fermentation time process (3-7 days of fermentation), keep quality of the tella sample for a month, by determining its pH, alcohol content, bitterness level and Sensory evaluation and also the shelf life was increase from time to time.