Here is a raw milk Gruyere I made at 1.5 months old. I’m posting the picture because it has developed an orange/yellow color. This is from b. linens bacteria. I did not inoculate the milk with b. linens, but it is a naturally occurring bacteria found in (raw) milk. If you use pasteurized milk you generally don’t encounter it unless you add b. linens. In addition to the characteristic color, b. linens creates a sticky texture on the exterior. I’m rubbing the cheese with a brine solution every few days to prevent other mold growth, but I’m excited for this good bacteria.