Filtration Challenges in Non-Alcoholic and Low-Alcohol Beer Production with a Focus on Different Yeast Strains  
[PERSON]  
1 Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704, USA; [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (B.P.G. ); [EMAIL_ADDRESS] (R.S.) [PERSON]  
3 Filtrox AG, Moosmuehlestr. 6, CH-9001 St. Gallen, Switzerland; [EMAIL_ADDRESS]  
[PERSON]  
1 Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704, USA; [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (B.P.G. ); [EMAIL_ADDRESS] (R.S.) [PERSON]  
1 Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704, USA; [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (B.P.G. ); [EMAIL_ADDRESS] (R.S.) [PERSON]  
1 Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704, USA; [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (B.P.G. ); [EMAIL_ADDRESS] (R.S.) [PERSON]  
1 Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704, USA; [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (B.P.G. ); [EMAIL_ADDRESS] (R.S.) [PERSON]  
1 Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704, USA; [EMAIL_ADDRESS] (M.A. ); [EMAIL_ADDRESS] (A.M.); [EMAIL_ADDRESS] (B.P.G. ); [EMAIL_ADDRESS] (R.S.) Footnote 1: email: {[EMAIL_ADDRESS], [EMAIL_ADDRESS], [EMAIL_ADDRESS], j.  
that combine these different methods can be used to closely mimic the flavor profile of alcoholic counterparts in non-alcoholic beers [5; 10]. The brewing of NABs provides extensive engineering possibilities for process optimization. This versatility highlights microbiological methods as a valuable approach for studying various yeast strains [4; 7] and their applications in downstream processes, including filtration. Filtration is a critical step in the production of beverages including NAB as it ensures product clarity, microbiological stability, and sensory quality [11; 12]. However, the process presents unique challenges due to the interaction between yeast, particle size, and the physicochemical properties of the NAB matrix [11; 12; 13]. Yeast plays a pivotal role in both the fermentation and filtration stages, and its characteristics, including size and surface properties, significantly influence the efficiency of filtration processes [12]. Yeast cells in beer production in general are larger than many other (non)suspended particles in the beer matrix, with diameters ranging from 3 to 10 \(\upmu\)m, depending on the species and strain [11; 12]. The size distribution of these cells is an important factor affecting filtration [12]. Larger yeast cells can form a more permeable filter cake, enabling faster flow rates and extending the filtration process without cleaning (increased throughput) but potentially reducing the retention of smaller particles. Conversely, smaller yeast cells and fragments, such as those resulting from autolysis, may clog filter pores and decrease filtration efficiency and throughput. The challenge lies in achieving a balance between adequate yeast removal and the maintenance of desired beer characteristics, such as haze stability and flavor. The physicochemical properties of yeast, such as cell wall structure and surface hydrophobicity, further complicate filtration dynamics. On the one hand, yeast with a more robust cell wall or a higher degree of hydrophobicity (e.g., flocculent yeasts) tends to adhere to filtration surfaces, which can lead to fouling and reduced filter life, especially in crossflow processes [14; 15]. On the other hand, yeast strains with weaker cell walls may release intracellular components, increasing the overall particle load and negatively impacting filtration and/or shelf life.