Note from Ricardo Milk other than whole milk can be used. Depending on the milk used, consistency and fermentation time may vary. The packet of powdered yogurt starter can be replaced with ¼ cup (60 ml) very fresh cultured plain yogurt. To help the milk cool down faster, heat only half of it (3 cups/750 ml). Remove from the heat, then add the remaining milk. The milk will cool to the desired temperature faster, in about 25 minutes.