It is especially important that strict rules of sanitation are followed when making ice cream because the dairy products in the mixtures provide the perfect breeding ground for bacteria. And, in those mixtures containing eggs, a high-protein food that is easily contaminated by salmonella, even greater care must be taken.
The following rules should always be maintained when preparing ice cream and ice cream products:
- Wash hands thoroughly before beginning preparation.
- Use only clean, sanitized bowls, and stainless steel or other noncorrosive utensils and storage containers.
- Use only the highest quality pasteurized dairy ingredients.
- Submerge small equipment in water with a temperature of 82°C–100°C (180°F–212°F) for at least 10 minutes.
- Follow manufacturer’s directions for operating and cleaning the machine and, even if not instructed to do so, always clean following these rules of sanitation:
- Ice cream machines should be cleaned with a chemical solution that has the proper concentration of an active chemical and sanitizing agent, such as regular laundry bleach. The surface being cleaned should be in contact with a mixture of 15 to 30 milliliters (1 to 2 tablespoons) bleach per 3.8 liters (1 gallon) warm (not above 38°C / 110°F) water for at least 1 minute.
- Do not use kitchen towels to wipe out machinery; they are not sterile. Instead, let the machine air dry.
- When breaking open eggs, do not allow the exterior of the eggshell to come in contact with the raw egg.
- Heat milk to just below the boiling point before combining with eggs.
- Cooked ice cream bases containing milk and eggs should be brought to 77°C–79°C (170°F–175°F) and held there briefly; whole eggs and egg yolks can be pasteurized by heating to 79°C (175°F).
- Use a clean spoon to taste mixtures.
- Cover any open wounds while handling ingredients and equipment.
- Do not blow on hot mixtures to speed cooling.
- Chill the finished product quickly in an ice bath and refrigerate immediately until ready to use.