Discover what gelatin is in a stock. Learn the science behind why a rich, well-made bone stock turns into a firm jelly when it gets cold.
1 Answer
Gelatin in stock is a protein derived from collagen in animal bones and connective tissues. A well-made bone stock becomes gelatinous when chilled because the collagen breaks down into gelatin during simmering, and the gelatin solidifies as it cools.
Detailed Explanation:
Gelatin is a protein substance derived from collagen, which is found in animal bones, skin, and connective tissues. When making bone stock, these ingredients are simmered for an extended period. This slow simmering process causes the collagen to break down. The breakdown of collagen results in the formation of gelatin, which dissolves into the stock.
When the stock is cooled, the gelatin molecules begin to bond together, forming a three-dimensional network that traps water. This network is what gives the chilled stock its characteristic jelly-like consistency. The more collagen-rich ingredients used and the longer the stock is simmered, the more gelatin will be extracted, resulting in a firmer, more gelatinous stock when chilled. A gelatinous stock is a sign of a well-made stock, indicating that a significant amount of collagen has been extracted.
Pro Tip:
To maximize gelatin extraction, consider using bones with a high proportion of cartilage and connective tissue, such as chicken feet, knuckles, and necks. Roasting the bones before simmering can also enhance the flavor of the stock.