Baked milk is a staple of Russian cuisine and, in particular, the Ukrainian diet. It is fresh milk that has been heated in an oven or simmered over low flame for most of the day or overnight. When simply scalded, milk is effectively pasteurized. More importantly, the baked variety acquires a delectable brown crust and even caramelizes completely. The happy accident of “overcooked” milk is in all likelihood the origin of custard and the Spanish dulce de leche spread and dessert.
Households in the remote reaches of Russia and the Ukraine needed to keep milk from spoiling while stored at room temperature. Before refrigerators became commonplace, most peasant cottages had roomy ovens at hand. Ovens then were kept fired most of the time. Placing a jug of milk closer to, or farther away from, the source of heat proved a convenient way of simmering or thoroughly baking milk. This method of killing off all microbes and enzymes that could sour milk gave rise to baked milk.
Refrigerators are widespread today, but the Russian taste for baked milk, or ryazhenka, remains, so has the appetite for soured milk and yogurt, born in the remote regions of the Caucasus. Throughout Russia and the Ukraine, therefore, there are factories that churn out all three forms of processed milk. Baked milk has become the generic word for these processed milk products because the otherwise bland taste of plain boiled milk was infused with good bacteria, the thermopile subspecies of milk streptococcus. Allowed to ferment a little, these deliver a taste closer to yogurt than regular baked milk. Such is the power of popular consensus, however, that this milk is more often than not associated with the tangy-tart taste of unflavored yogurt.
Owing to the variety of ethnic and rural practices associated with its origins, baked milk varies in appearance, texture, and taste. At one end of the spectrum, the product remains white but is a thickened version of fresh whole milk. At the other extreme, there is the savory crust and heavily caramelized, syrupy, smoothie-like texture of thoroughly baked milk. In between are the beige-colored, still-liquid beverages commonly found in Russian and Polish groceries throughout Europe and North America.
Far from being just a Slavic or Eastern European ethnic taste, baked milk has traveled all across Europe, crossed the Atlantic to South America courtesy of Spaniard and Portuguese conquistadores, and even traveled the trade routes to India. Along the way, variants developed. The French confiture de lait is a spreadable and sweetened product. The Norwegians like it thicker, but not too sweet. Italians flavor theirs with hazelnut, while Indians typically prefer the spice of cardamom.