Temping Your Hopper

• Soft-serve machines have two areas of concern when it comes to freezing temperatures. The reservoir where the yogurt mix is poured is called the hopper, and the ideal hopper temperature lies around 35 degrees Fahrenheit. Arriving at the correct temperature for your hopper is a delicate balance. Temperatures above 40 degrees F will cause the yogurt to spoil; temperatures below 32 degrees F will cause the yogurt to freeze. Monitor the temperature in the hopper with a food-grade thermometer to ensure proper temperatures are met, and adjust the temperature when needed.

The Dispensing Temperature

• The second critical area of concern for appropriate freezing involves the dispensing temperature, which should also be the same temperature as the freezing cylinder. Soft-served frozen yogurt made with pure fruit sugar should be dispensed at approximately 17 to 19 degrees F. If your yogurt mix uses cane sugar then the temperature should be raised to approximately 22 degrees F. Adjust the temperature on your machine if needed.

Correct Frozen Texture

• When correct temperatures are used, the consistency of your frozen yogurt should be stiff and creamy. Water and air play essential roles in achieving this preferred consistency. Air is incorporated into the frozen yogurt through continuous rotation, which adds volume; and the water present in yogurt won’t actually freeze, but instead will form ice crystals, which create a partly firm and partly soft state ideal for dispensing.

Freezing Cultures 101

• Freezing yogurt does not kill substantial amounts of live cultures. When frozen, cultures actually go into a dormant state and when consumed they become active again. However, not all frozen yogurt has live cultures. Some manufactures use heat-treated yogurt, which kills the live cultures. Traditional fermentation is the best way to insure that frozen yogurt retains its live cultures. To maintain these cultures, some manufactures will add them back before freezing. To guarantee your frozen yogurt includes live cultures, check the label for the NYA (National Yogurt Association) "Live & Active" cultures seal, which assures traditional fermentation has taken place.