Early spoilage in fresh cheese contributes to food loss and negatively affects consumer experience. Traditional preservatives, like sorbates and propionates, are being removed due to consumer demand for clean labels. Protective cultures represent a potential clean label alternative for spoilage control. The study objective is to investigate bacterial cultures efficacy in bio-preserving cottage cheese against post-processing yeast contamination. Cottage curd and dressing were sourced from a manufacturer in New York. Dressing was inoculated with 3 different commercial protective cultures (of Lactobacillus spp. designated PC1, PC2 and PC3) following manufacturer recommended dosage. Curd was added to dressing and mixed. A positive control (PC) with no protective culture was included. Eight genera of yeast previously isolated from dairy processing environments (Pichia fermentans, Clavispora lusitaniae, Debaryomyces hansenii, D. prosopidis, Candida zeylanoides, Rhodotorula mucilaginosa, Meyerozyma guilliermondi and Torulaspora delbrueckii) were spotted on cheese surface at a rate of 100 cfu/5 g of cheese. Samples were stored at refrigeration temperature (6 ± 2°C). To enumerate yeast levels at 0, 7, 14 and 21 d post-inoculation, samples were homogenized in phosphate buffer saline, serially diluted, plated on potato dextrose agar with chloramphenicol, and incubated at 25°C for 5d. Studies were performed in duplicate with technical replicates. Average yeast counts were log-transformed, and JMP Pro was used to analyze data using least squares method and Tukey’s test at significance level (P = 0.05). Negative control showed no growth throughout 21d. For P. fermentans, C. lusitaniae, D. hansenii, D. prosodies, C. zeylanoides and R. mucilaginosa, treatments showed no significant difference at 21d. For M. guilliermondii, counts were ~1 log lower at 21d in PC1 versus PC, PC2 and PC3 (P < 0.05). Similarly, T. delbrueckii, counts were ~2 log lower at 21d in PC1 compared with PC, PC2 and PC3 (P < 0.05). The study shows potential efficacy of PC1 against M. guilliermondii and T. delbrueckii in cottage cheese. The study demonstrates that protective cultures potential to inhibit yeast in cottage cheese is strain selective.