## 3 Results and Discussion
### Filtration Impact on NABs Breved and Analyzed  
#### 3.3.1 NAB Filtration Performance and Impact on Fresh Products  
The filtration parameters assessed in this study were limited in scope and do not encompass key technical variables typically used to evaluate filtration performance, such as flow rate, filtration time, pressure drop, or filter loading capacity. These parameters are ultimately necessary for assessing the efficiency and economic feasibility of filtration processes in an industrial brewing context. Moreover, filtration setups in breweries vary considerably, ranging from sheet and candle filters to crossflow membrane systems, and each of these techniques operates under distinct process conditions [12]. As such, the limited scale and simplified filtration setup used in this study (i.e., a two-sheet lab-scale filter with a fixed filtration volume of 5 L and a constant pressure of 1 bar) limit the comparability of the data with industrial filtration practices, and the results should be compared with those in the appropriate context. To highlight the practical implications of employing various filter media and yeast strains in the production of low-alcohol and non-alcoholic beers, this study did not include a detailed analysis of haze composition. Instead, the focus was placed on monitoring haze reduction and observing potential changes in unstabilized beer stored at 4 \({}^{\circ}\)C over a two-week stability testing period. Turbidity levels in beers fermented with LA-01 and LoNa decreased over the course of the filtration trials, whereas W-34/70 exhibited a significant increase in turbidity, exceeding 250 EBC (Figure 2). This variation can be attributed to differences in yeast flocculation characteristics and the fermentation tanks used. LA-01 and LoNa are classified as non- to medium-flocculent yeasts [20; 21], which facilitated effective sedimentation and subsequent removal during filtration. Since all beers were filtered from a single fermentation tank, the observed turbidity reduction can be explained by yeast sedimentation and retention within the filter matrix (AF 11 \(\rightarrow\) AF 101). Conversely, W-34/70 is a highly flocculent yeast strain [22], and it accumulated on the inner cooling coils of the fermenter. Upon emptying the fermenter, aggregated yeast clumps were released \begin{table}
\begin{tabular}{l c c c c c} \hline \hline  & **Original Extract** & **Bitterness** & **Alcohol** & **Apparent Degree of** & \\  & **[\% _w/w_]** & **[BU]** & **[\% _v/v_]** & **[\%]** & **[-]** \\ \hline LA-01 & 6.56 \({}^{\text{a}}\)\(\pm\) 0.01 & 11.1 \({}^{\text{a}}\)\(\pm\) 0.2 & 0.53 \({}^{\text{c}}\)\(\pm\) 0.00 & 15.51 \({}^{\text{c}}\)\(\pm\) 0.01 & 4.40 \({}^{\text{a}}\)\(\pm\) 0.00 \\ LoNa & 6.59 \({}^{\text{a}}\)\(\pm\) 0.00 & 11.0 \({}^{\text{a}}\)\(\pm\) 0.0 & 0.56 \({}^{\text{b}}\)\(\pm\) 0.00 & 16.26 \({}^{\text{b}}\)\(\pm\) 0.00 & 4.36 \({}^{\text{a}}\)\(\pm\) 0.01 \\ W-34/70 & 6.56 \({}^{\text{a}}\)\(\pm\) 0.00 & 11.2 \({}^{\text{a}}\)\(\pm\) 0.1 & 2.33 \({}^{\text{a}}\)\(\pm\) 0.01 & 68.91 \({}^{\text{a}}\)\(\pm\) 0.00 & 3.99 \({}^{\text{b}}\)\(\pm\) 0.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Basic analytical results for NABs after fermentation (constant alcohol readings over 2 days); superscript letters indicate LS mean groupings (Fisher LSD, \(p<0.05\)). into the beer stream, entering the filter system and contributing to the observed increase in turbidity. Among the filter sheets tested, AF 11 exhibited the lowest filtration efficiency, as indicated by the highest turbidity levels across all beer samples (Figure 2). Despite the high yeast load in the inlet for LA-01 and LoNa, the final turbidity values remained elevated at 39.3 EBC and 71.5 EBC, respectively, demonstrating visibly turbid filter outlet samples.