PRB6, 5 Doses, Liquid by Danisco is lactose free. This is blue-green Hyptonic that produces a traditional Gorgonzola, Stilton, bleu d’ Auvergne or Fourme d’Ambert style blue cheeses. PRB6 produces a very strong blue cheese aroma. In a commercial setting this bottle can make up to 650 gallons of milk into blue cheese. In a non-commercial setting us ¼ tsp per 2 gallons of milk. Per Amazon policy, we cannot accept back food-based perishable items. An ice pack is available for purchase if you wish to protect your product during the summer months.