## 3 Results  
### Effect of Particle Size on the Physicochemical Characteristics of Umqombothi  
There were five separate sample phases in the Umqombothi manufacturing process, namely before the first fermentation (first sample), after the first fermentation (second sample), before the second fermentation (third sample), after the second fermentation (fourth sample) and, lastly, the final product (fifth sample). Table 1 displays the pH that was attained throughout the Umqombothi production process. There was a significant (\(p<0.05\)) difference in the pH between the sampling stages for the control particle sizes, except for the second and fifth sample stages. The significant (\(p<0.05\)) decrease in pH is due to a significant increase in LAB during the Umqombothi production process, specifically in the first and the fifth stages for the control, coarse, and fine powder particle sizes. The lactic acid bacteria produced lactic acid and acetic acid, causing the pH to decrease significantly. The pH for the control, coarse, and fine powder particle sizes align with previous results reported for Umqombothi [9; 16; 24]. The current study confirmed that the particle size influenced the pH of Umqombothi during the production process. The lower the particle size, the higher the pH level during the fifth sampling stage. Beverages with a significantly low pH last longer in storage, have superior safety and quality, and have antimicrobial properties. The beverages with a low pH assist in the removal of harmful microorganisms that may constitute a health risk [25]. When contrasting how the fermentation temperature affects the pH, there was no significant difference between the overall particle sizes on the pH of coarse (4.08) and fine powder (4.07). The control particle size was significantly (\(p<4.13\)) higher than the coarse and fine powder particle sizes. According to [9], beverages with a lower pH (4.07), such as those with fine powder/coarse powder particle sizes, offer better quality and safety, an extended shelf life, and stronger antibacterial qualities. The overall pH for the control, coarse, and fine powder particle sizes, respectively, are higher than the pH of 3.67 reported by [16; 24] on the final Umqombothi product. This could be due to the fermentation period, or the source of the grains and inoculum used. Umqombothi has a moisture content of 94.67% and a limited shelf life of 1-3 days, according to [24]. Foods with high moisture content are more prone to microbial development, reducing its shelf life. The effect of excessive moisture on the shelf life of Burukutu, Ghana's traditional beverage, was studied by [26]. Sorghum fermentation usually activates enzymes, decreases the pH, and increases metabolic and microbial activity. This causes the breakdown of starch, enhancing the nutritional quality [9]. The activity of enzymes is affected by the pH, which is essential in liquefaction and the conversion of malt starch into fermentable sugars [24]. Furthermore, an elevated pH promotes microbial growth by lowering proteinase and amylase activity and stability [27]. Table 2 shows the influence of different particle sizes on the TSSs, during the making of Umqombothi. There was a substantial (\(p<0.05\)) variation in the control, coarse, and fine powder particle sizes, between all the sample phases. As the starch granules gelatinize, the endosperm protein that encircles them becomes softer, which results in the transfer of the grain into the retting water and a subsequent increase in the concentration of total soluble solids. This could explain why the TSSs increase during the fermentation and third sampling stages. Cooking the sour porridge long enough allows the starch to gelatinize and the yeast cell's lockup nutrients to be released. The TSSs level is influenced by the cooking time and particle size [28]. As the second fermentation stage progresses, the accessible solids are utilized by microorganisms, such as yeast, to create alcohol and an aroma [17].