Gelling

Gelling refers to the process of a liquid, often a colloid or sol, transitioning into a more solid, semi-rigid state. This transformation usually involves the formation of a network structure within the liquid, trapping the liquid molecules and increasing viscosity until a gel-like consistency is achieved. The driving force behind gelling can vary, ranging from cooling to chemical reactions, and the resulting gel's properties depend on the specific substances and conditions involved. This process is crucial in many applications, from food science and cosmetics to materials science and pharmaceuticals.

Gelling meaning with examples

• The chef carefully monitored the custard mixture as it cooled, watching for the subtle signs of gelling to indicate the dessert was reaching the perfect consistency. The sugar-starch molecules were starting to bond. Too much heat before or after could ruin the mixture, and result in a different form.
• After adding the agar-agar to the broth, the mixture was heated and then allowed to cool in the refrigerator, gelling into a clear jelly that would be used as an aspic. This involved cross-linking the molecules to trap the liquid, which is the whole purpose of the process.
• The scientist experimented with different polymers, observing how their solutions would undergo gelling when exposed to varying levels of UV light. Careful observation was required to see if the result was a success, or if the solution was too runny or too hard.
• The hair gel underwent a gelling process in the manufacturing plant, resulting in a product that holds its shape well. The correct chemicals, in the right amounts, in a sealed vessel were what lead to success. Testing each batch ensured quality.