10/15/2026
Daily Food Trivia: October 15
Today, October 15th, is National Cheese Curd Day.
Key Culinary Facts & History
Rennet Coagulation: The transformation of milk into curds relies on chymosin, an enzyme found in rennet. Chymosin selectively cleaves the water-soluble kappa-casein "hairs" on milk protein micelles. Stripped of this layer, the casein proteins instantly bond together, forming a rigid 3D gel matrix while expelling liquid whey.
The Physics of the "Squeak": The hallmark of a fresh cheese curd is its signature squeak. This acoustic phenomenon occurs because the curd’s internal architecture is a tight, elastic web of calcium-bound proteins. Biting into the curd stretches this rubbery matrix until it snaps back, vibrating against the tooth enamel to produce an auditory squeak.
The Cheddaring Process: Before becoming blocks of cheese, the coagulated gel is cut and subjected to "cheddaring." The curds are formed into large slabs, stacked, and flipped to press out residual whey and knit the proteins into long fibers. The slabs are then milled back into small, bite-sized pieces—the final curds.
Emulsion Stability: Because fresh curds are unaged, their protein structures haven't been broken down by proteolytic enzymes, and their pH remains mild. This allows them to melt exceptionally smoothly without their fat emulsions splitting, making them an ideal foundation for a velvety, creamy b**r cheese dip served alongside warm pretzels.
Squeak Degradation: The famous squeak is ephemeral, typically disappearing within 24 hours. As curds sit, lactic acid bacteria continue to produce acid, lowering the pH. This acidity slowly dissolves the calcium phosphate cross-links holding the protein web tight, causing the cheese to soften and permanently lose its acoustic rubberiness.