keltés

Keltés, in the context of baking, is the process by which dough ferments and rises due to gas production by yeast or bacteria. The term derives from Hungarian kelés, meaning rising, and denotes the leavening stage that develops volume, structure, flavor, and crumb in bread and other baked goods.

The mechanism of keltés involves yeast metabolizing sugars to produce carbon dioxide and alcohol. The carbon dioxide inflates the gluten network, causing the dough to expand. In addition to yeast-based fermentation, sourdough and other fermented starters rely on lactic acid bacteria that contribute acidity and complex flavors. The rate and extent of keltés are influenced by temperature, hydration, sugar content, salt, and time: warmer conditions speed up fermentation but can reduce flavor depth; salt slows yeast activity; excessive time can lead to overproofing and weakened dough structure.

There are two main approaches to keltés. Yeast-based leavening uses commercial baker’s yeast in forms such as active dry, instant, or fresh yeast, typically with a relatively short proofing period. Sourdough fermentation uses a starter of wild yeasts and lactic acid bacteria, offering longer fermentation and distinctive tang. Some recipes incorporate preferments like poolish, biga, or sponge to develop flavor during keltés.

Process and outcomes vary with recipe, but common steps include mixing, bulk fermentation, gentle folding or shaping, and final proof before baking. Proper keltés yields a light, open crumb and a crisp crust; underproofed dough remains dense, while overproofed dough can collapse. Refrigerated or retarded fermentation can enhance flavor and management.