This Thermophilic culture is added directly to your milk and takes all the muss and fuss out of the culturing process. Thermophilic Culture Includes: lactose, (ST) streptococcus thermophilus, (LB) lactobacillus delbrueckii subsp. bulgaricus, (LH) lactobacillus helveticus. YIELD: Each packet will set 2 gallons of milk. DIRECTIONS: Add 1 packet directly into your milk at the proper temperature when the recipe calls for adding starter culture. STORAGE: Keep packages in the freezer, they will last up to 2 years.