This research explores using naturally occurring yeasts found in cheese to prevent mould spoilage, offering a chemical-free alternative to current preservatives. Scientists tested 84 yeast strains and identified the most promising ones that can inhibit growth of three common spoilage moulds through different mechanisms like enzyme production and nutrient competition. Two yeast strains, Geotrichum candidum GC663 and Pichia jadinii PJ433, showed particularly strong potential for protecting cheese quality and extending shelf life when tested in actual cheese.