Nước Mắm Cốt Nhỉ Tự Nhiên is a highly concentrated traditional fish sauce produced by Liên Thành. It is made from fresh anchovies and sea salt without added preservatives, sweeteners, colorings, or artificial flavorings. The fish are salted immediately after the catch to preserve their freshness before fermentation begins. The anchovies and salt mature in wooden barrels for between 15 and 18 months. During fermentation, the fish proteins naturally break down and produce amino acids responsible for the pronounced umami flavor. The term cốt nhỉ refers to the first drops of concentrated sauce that are gradually extracted from the matured fermented fish mixture. The product consists entirely of this first-press anchovy extract and is not blended with sauces of a lower concentration. The version commonly available on the Vietnamese market is labeled with a total nitrogen concentration of 45 grams per liter. The finished sauce has a clear reddish-brown color, an intense fermented-anchovy aroma, and a full salty flavor followed by natural sweetness. It is intended for direct serving as a dipping sauce but can also be used in marinades, dressings, and dishes that require a small amount of concentrated fish sauce.