This is a freeze-dried mixed blend culture containing Penicillium Roqueforti and Aromatic Mesophilic. Penicillium Roqueforti (VZ3) is an important ingredient in the production of blue cheese. It is a dried, powdered conidia produced from the fungus Penicillium roqueforti and is responsible for the blue mould which appears in your cheese. Aromatic Mesophilic (YV32) is essential in creating the creaminess and buttery flavour in the cheese. Strains included in this culture are; Penicillum roqueforti, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Lactococcus lactis subsp lactis biovar diacetylactis, Leuconostoc. Each sachet contains enough culture for 4 L of milk. The Blue Mould Culture blend lasts out of the freezer (at room temperature) for 2 months so will be fine during postage. However, we suggest storing them in the freezer as soon as you get them in order to prolong their life.