Lactic acid bacteria have long been used in brewing to acidify mash or wort and in the production of traditional sour beer styles (Lambic, Gueuze) using spontaneous fermentation. This approach is time consuming (some sour beers are matured for three years to obtain the appropriate flavour), so many brewers choose a faster approach using mixed cultures (yeast and bacteria). In this study, the influence of the pitching sequence of bacteria and yeast on the fermentation process was evaluated (by rate of fermentation and acidification, attenuation degree and ethanol concentration). The trials were performed using three procedures: (i) the addition of bacteria followed by the yeast; (ii) the addition of the yeast followed by the bacteria and (iii) the simultaneous addition of yeast and bacteria. In each trial the following time intervals were applied: 24, 48 and 72 h. Weight loss of samples and drop in pH were measured daily, and ethanol content, real extract and lactic acid concentration measured at the end of the process. It was shown that the order of addition of yeast and bacteria determines the success of the lactic acid fermentation. The appropriate yield of lactic acid (ca. 6 g/L) and the drop in pH (<3.6) can be achieved by inoculating the bacteria prior to the inoculation of yeast. When yeast was pitched before the bacteria, the lactic acid content was ca. 2 g/L and pH was 3.9–4.2. © 2019 The Institute of Brewing & Distilling

中文翻译：

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酸啤酒的生产：酵母和乳酸菌的推销顺序的影响

长期以来，乳酸菌一直用于酿造酸化糖浆或麦芽汁，并用于通过自发发酵生产传统酸味啤酒（Lambic，Gueuze）。这种方法很费时间（有些酸啤酒要熟化三年才能获得合适的风味），因此许多啤酒酿造者选择使用混合培养物（酵母和细菌）的更快方法。在这项研究中，评估了细菌和酵母的投料顺序对发酵过程的影响（通过发酵和酸化的速率，衰减度和乙醇浓度）。该试验使用三种方法进行：（i）添加细菌，然后添加酵母；（ii）添加酵母，然后添加细菌；（iii）同时添加酵母和细菌。在每个试验中，采用以下时间间隔：24、48和72小时。每天测量样品的重量损失和pH下降，并在过程结束时测量乙醇含量，实际提取物和乳酸浓度。结果表明，酵母和细菌的添加顺序决定了乳酸发酵的成功。可以通过在接种酵母之前接种细菌来实现适当的乳酸产量（约6 g / L）和pH值下降（<3.6）。当将酵母置于细菌之前时，乳酸含量约为。2 g / L，pH为3.9-4.2。©2019酿酒与蒸馏研究所 结果表明，酵母和细菌的添加顺序决定了乳酸发酵的成功。通过在接种酵母之前接种细菌，可以实现适当的乳酸产量（约6 g / L）和pH值下降（<3.6）。当将酵母置于细菌之前时，乳酸含量约为。2 g / L，pH为3.9-4.2。©2019酿酒与蒸馏研究所 结果表明，酵母和细菌的添加顺序决定了乳酸发酵的成功。可以通过在接种酵母之前接种细菌来实现适当的乳酸产量（约6 g / L）和pH值下降（<3.6）。当将酵母置于细菌之前时，乳酸含量约为。2 g / L，pH为3.9-4.2。©2019酿酒与蒸馏研究所