This work aimed to estimate the inactivation kinetic parameters of four potential beer spoilage bacteria (Lactobacillus brevis DSM 6235, Lactobacillus casei ATCC 334, Pediococcus damnosus DSM 20289 and Pediococcus damnosus ATCC 29358) inoculated in brewing yeast submitted to acid washing with purposes of yeast recycle. The experiments were conducted at 4 °C in solutions with pH 1.5, pH 2, and pH 3 adjusted employing 85% phosphoric acid. The acid washing treatment of brewing yeasts in the most common pH used (pH 2.0) demanded almost 50 min for the first decimal reduction (δ) of L. brevis DSM 6235. Sensible strains to acid washing such as P. damnosus DSM 20289 demanded almost 70 min for 4 log reductions to be achieved. On the other hand, pH reduction of the acid washing from 2.0 to 1.5 allowed 4 log reduction of L. brevis DSM 6235) to be obtained in less than 50 min, without ruining brewer's yeast viability. Acid washing in pH 1.5 is a viable method for the inactivation of bacterial contaminants of brewing yeasts. Recycling of brewing yeasts through this approach may contribute to a more sustainable and environmental-friendly industry.

这项工作旨在评估在酿造酵母中接种的四种潜在啤酒腐败细菌（短乳杆菌DSM 6235 ，干酪乳杆菌ATCC 334，丹氏Pediococcus damnosus DSM 20289和丹氏Pediococcus damnosus ATCC 29358）的灭活动力学参数，这些酸经过酵母洗涤后用于酸洗。实验是在4°C的pH值为1.5，pH 2和pH 3的溶液中使用85％磷酸调节的。在最常用的pH值（pH 2.0）中对酿造酵母进行酸洗处理需要将近50分钟，以使短乳杆菌DSM 6235的第一个小数位降低（δ）。对酸洗的敏感菌株，如丹尼酵母DSM 20289要求将近70分钟才能减少4个对数。另一方面，酸洗液的pH值从2.0降低到1.5 ，可在不到50分钟的时间内将短乳杆菌DSM 6235降低4 log ，而不会破坏啤酒酵母的活力。pH 1.5的酸洗是灭活酿造酵母细菌污染物的可行方法。通过这种方法回收酿造酵母可以促进更可持续和环保的行业。