Yuyao Salted Egg

Yuyao Salted Egg

Yuyao Salted Egg is a geographical indication protected product.

　　Yuyao Salted Egg

　　The administrative regions currently under the jurisdiction of 14 towns in Yuyao City, Zhejiang Province, including Simen Town, Moushan Town, Liangnong Town, Hemudu Town, Luting Township, Huangjiabu Town, Xiaocaobo Town, Sanqishi Town, Lubu Town, Dalan Town, Linshan Town, Zhangting Town, Dayin Town, Mazhu Town

　　 "The Reply of the People's Government of Yuyao City on Approving the Application for Declaring the Geographical Indications of Origin of 'Yuyao Salted Egg' and 'Yuyao Century Egg'", Yu Zheng Fa [2011] No. 104

　　"Technical Specifications for Quality Control of Yuyao Salted Eggs" by Ningbo Jinluan Poultry Egg Food Co., Ltd., Ning Jin Ban [2012] No. 05

　　Quality and Technical Requirements for Yuyao Salted Egg

　　I. Requirements for Raw Materials and Auxiliary Materials.

　　1. Duck Eggs:

　　(1) Breed: Local Muscovy ducks with ringed white-wing-tipped feathers.

　　(2) Rearing Requirements:

　　① Rearing Environment: The rearing grounds are located in the lake area within Yuyao, with duck beaches and water enclosures each covering no less than 50㎡ per 100 ducks. The water depth in the enclosures shall be greater than 1m.

　　② Rearing Management: The feed consists of a mixture of locally produced distiller’s grains, shell powder, corn flour, wheat flour, fish meal, and other self-formulated ingredients, with no artificial colorants added to the daily ration.

　　③ The rearing environment, rearing process, use of feed and feed additives, and use of veterinary drugs shall comply with relevant national regulations.

　　(3) Requirements for Raw Eggs: Fresh local duck eggs not exceeding 7 days old. Eggshells must be clean; upon cracking, the yolk should be raised, resilient, and the egg white clear and transparent, free from impurities, odors, blood clots, or any other foreign tissues.

　　2. Auxiliary Materials:

　　(1) Processing Water: Should be sourced from the water supply in the Siming Mountain area of Yuyao, with water quality meeting national standards for drinking water.

　　(2) Yellow Clay: Should be selected from the mountain yellow clay in the Siming Mountain area of eastern Zhejiang; the soil must be odorless, unpolluted, free from impurities, with good viscosity and dried.

　　(3) Edible Salt: Should comply with national standards for table salt.

　　II. Processing Technology

　　1. Process Flow: Egg Selection → Ingredient Mixing → Pickling → Cleaning → Weighing and Grading → Vacuum Packaging → High-Temperature Sterilization → Cooling.

　　2. Key Processes:

　　(1) Egg Selection: Rotate and lightly inspect the eggs under light to eliminate defective ones such as those without pores, poor permeability, or sandy shells.

　　 (2) Ingredient Mixing:

　　① Preparation of Pickling Solution: Mix edible salt and water according to a specific formula, stir well until a brine with a concentration of 28% to 32% is achieved, to be used as the pickling solution.

　　 ② Preparation of Mud Mixture: Mix the prepared pickling solution with mountain yellow clay in a certain ratio to form the mud mixture.

　　(3) Pickling:

　　① Brine Pickling: Layer the selected fresh duck eggs in the pickling solution. When the temperature is ≥28°C, the pickling time is 25 to 30 days; when the temperature is 20°C to 28°C, the time is 35 to 40 days; when the temperature is 10°C to 20°C, the time is 60 to 70 days; when the temperature is ≤10°C, the time is more than 80 days.

　　②Mud curing: Coat fresh duck eggs evenly with the curing mud, then sprinkle a layer of plant ash or rice husk on the surface for curing. The curing duration is approximately the same as that of brine curing.

　　　 （4）Cleaning: Wash the eggshells to remove impurities and air-dry.

　　 （5）High-temperature sterilization: After vacuum packaging, the salted eggs undergo high-temperature sterilization with a core temperature of 120°C to 126°C for 20 to 30 minutes.

　　 III. Quality Characteristics

　　1. Sensory characteristics:

　　(1) Appearance: After shelling, the egg white is intact and does not stick to the shell, without any "honeycomb" appearance. The yolk is firm, with a grayish-black membrane between the yolk and the white.

　　(2) Color: The egg white is clean and white; the yolk is red or golden.

　　(3) Aroma and flavor: Possesses the distinctive aroma of Yuyao salted eggs, with moderate saltiness, rich fragrance, and a crumbly, savory yolk. The egg white is fine-textured and free of off-flavors.

　　2. Physicochemical indicators: Salt (calculated as sodium chloride) 2% to 6%; moisture 60% to 68%; fat ≥12%; volatile basic nitrogen ≤10mg/100g, iron ≥3μg/100g.

　　3. Safety and other quality technical requirements: The product must meet national regulations regarding safety and other quality technical standards.