產于河南羅山。產地地處豫北丘陵山區，氣候溫濕，河道縱橫，靈山鴨生長條件優越，無然餌料來源充足，所以產蛋個大、黃大、味純。腌制時采用地方傳統工藝。經選蛋、過照、驗質、稱重后。輔以當地產毛尖香茶、深井甘泉、糖、鹽等多種原料熬制料水，浸泡缸底。根據季節氣候變化調整料水溫度。待5-6周后成熟、出缸。精選皮色好、無裂紋、彈性足者出口。
    
    松花蛋又稱皮蛋、變蛋、灰包蛋（因為制做是有一層石灰包裹，很形象的名字！）等，口感鮮滑爽口，色香味均有獨到之處。制作皮蛋的主要原料有生石灰，純堿，食鹽,紅茶，植物灰（含有氧化鈣，氫氧化鉀）。皮蛋是我國一種傳統的風味蛋制品，
    
    松花蛋不僅為國內廣大消費者所喜愛，在國際市場上也享有盛名。經過特殊的加工方式后，松花蛋會變得黝黑光亮，上面還有白色的花紋，聞一聞則有一種特殊的香氣撲鼻而來。經過歷史的演變，松花蛋和咸鴨蛋已經成了我國最受歡迎的風味蛋，也逐漸形成了端午節吃兩蛋的習俗。每每到了端午節，除了傳統的粽子以外，咸鴨蛋和松花蛋也成了饋贈親友的佳品！松花蛋，不但是美味佳肴，而且還有一定的藥用價值。王士雄《隨息居飲食譜》中說：“皮蛋，味辛、澀、甘、咸，能瀉熱、醒酒、去大腸火，治瀉痢，能散能斂。”中醫認為皮蛋性涼，可治眼疼、牙疼、高血壓、耳鳴眩暈等疾病。松花蛋的傳統制法，幾乎都用到中藥密陀僧，但皮蛋中的鉛含量使人望而生畏。現在人們己研制出了無鉛皮蛋的制法，愛吃皮蛋的人們，不必為鉛中毒而擔心了。
    
    成品松花蛋，蛋殼易剝不粘連，蛋白呈半透明的褐色凝固體，蛋白表面有松枝狀花紋，蛋黃呈深綠色凝固狀，有的具有溏心。切開后蛋塊色彩斑斕。食之清涼爽口，香而不膩，味道鮮美。



    Xinyang Preserved Duck Eggs are produced in Luo Mountain, which is located in hill region in North Henan and owns moderate climate and intertlaced rivers. This advantageous climate and natural conditions provide plentiful natural forages for ducks and drive them lay big, yellow, taste-authentic eggs. Salted eggs are made depending on local traditional technique and combining with local Maojian tea, sweet spring water, sugar, salt and many other condiments, then being soaking at the cylinder bottom for 5 to 6 weeks, during this process altering water temperate according to changes of climate.
      
    Preserved duck eggs, also called Pidan, is not only well welcomed by Chinese customers but also enjoys a good reputation in the world. Finished preserved duck eggs has characteristics of easy to peel without conglutination; having transparent and brown solid egg white covered with pine-liked patterns, dark green solid yolk; colorful, cool, refreshing, delicious but not greasy.  With time passing by, preserved duck eggs has become a most well-welcomed flavor egg and is often used as gifts in the Dragon Boat Festival.  
      
    Preserved duck egg is not only a delicious snack, but also contains medical functions of curing sore eyes, teeth-ache, high blood pressure and other diseases. Nowadays, to our joy, people has developed its traditional technique, which always made eggs containing poisonous Pb, and created no-Pb preserved duck eggs.