Conventionally, filtration and centrifugation are used to separate yeast from suspensions. Mini hydrocyclones (10 mm diameter) have previously been shown to achieve limited dewatering of non-flocculating Bakers’ yeast. This indicated the potential of the application of hydrocyclones to the concentration of naturally flocculating Bakers’ or Brewers’ yeast suspensions, where the effective particle size is larger. In this study, the effect of degree of flocculation on the concentration of flocculating Brewers’ yeast suspensions was investigated. The separation performance was determined when varying the floc size and feed concentration. Variation in yeast flocculation was achieved by reducing the pH with acetic acid, which produced narrow floc size distributions, with median sizes between 200 μm and 20 μm. The feed yeast concentration range investigated was between 0.6 and 14g/L.

Stable yeast flocs do not break on passage through the hydrocyclone. Separation improved significantly with increasing floc size. Flocculation allowed enhanced separation, as compared to results obtained for unicellular, non-flocculating Saccharomyces cerevisiae. Increasing the feed concentration decreased the recovery of yeast to the concentrated product and the concentration ratio between feed and product. This is in agreement with previous findings for single cellular yeast. An interaction between floc size and suspension concentration on the separation was found with separation performance maximised for concomitant increase in floc size and decrease in yeast concentration. Typical results indicate that the concentration can be doubled and some 70–85% of the yeast recovered in a single pass through the system.

Furthermore, yeast quality and fermentation performance were not compromised by passage through the hydrocyclone.

常规地，过滤和离心用于从悬浮液中分离酵母。微型水力旋流器（直径10毫米）先前已显示出对非絮凝贝克面包酵母的有限脱水作用。这表明将水力旋流器应用于自然絮凝的Bakers或Brewers酵母悬浮液浓度的潜力，其中有效粒径较大。在这项研究中，研究了絮凝度对絮凝的Brewers酵母悬浮液浓度的影响。当改变絮凝物尺寸和进料浓度时，确定了分离性能。酵母絮凝的变化是通过用乙酸降低pH值来实现的，这会产生狭窄的絮凝物尺寸分布，中值粒径在200μm至20μm之间。

稳定的酵母絮凝物在通过水力旋流器时不会破裂。随着絮凝物尺寸的增加，分离效果显着改善。与单细胞，非絮凝酿酒酵母获得的结果相比，絮凝可以增强分离效果。饲料浓度的增加降低了酵母向浓缩产物中的回收率以及饲料与产物之间的浓缩比。这与单细胞酵母的先前发现是一致的。发现絮凝物大小和悬浮液浓度之间存在相互作用，分离性能最大化，从而伴随絮凝物尺寸增加和酵母浓度降低。典型结果表明，该浓度可以加倍，并且一次通过系统即可回收到约70-85％的酵母。

此外，通过水力旋流器不会损害酵母的质量和发酵性能。