At K-bröd, we preserve dairies to make three different products:  cultured butter,  skyr, and  cheese. We take a holistic approach to dairy preservation; in this way, we formerly preserve the cream and secondly preserve the milk.
Cultured butter, cultured milk
Lactic acid preservation of cream and milk is as old as the domestication of dairy-producing animals. While the isolation of live bacteria cultures is relatively recent, it is possible that the original bacteria that cultured the first dairy products could be traced to a single source, since the trade of a cultured dairy product is far easier and likelier than the accidental invention of a probiotic dairy product at multiple times and locations. Once some dairy has been cultured, it is quite easy to culture a new batch. Because cream and milk come from the safety of an animal’s body, immediately culturing it and keeping it out of heat of the day temperatures will have a nearly 100 percent success rate for producing cultured butter or yogurt. Modern artisans must heat the milk to be sure of its safety before culturing, but cream is normally ready to be cultured straight from the carton.
Yogurt and cheese are preserved using two different methods for the same milk product. Yogurt, like cultured butter, is infused with probiotic bacteria that produce lactic acid, in which these bacteria thrive but most other kinds of microbes fail to grow in. Cheese, on the other hand, is coagulated with rennet (a product often made from the bones of a baby cow) and strained. The coagulated, dry environment is hospitable to good bacteria that stink pleasantly, but is unfriendly to other kinds of microorganisms. The humble homemade cheese we produce is ethnically called gammelost, and commonly called priest cheese, after the monks who let the curd ripen on their windowsill while copying classical manuscripts.
Preserved dairies are really good for you. Lactic acid fermentation preserves rare vitamins and minerals that would be destroyed by other forms of preservation, such as heating or bleaching. The good bacteria in cultured butter and yogurt improves digestive health. Enjoy these products at room temperature to taste their delicious, acidic tang.
The acidity in fermented dairies turns the uninitiated off, because they want sweet soft cream, like what French and Italian people eat. If I embrace the acidic flavor of fermented dairies, however, the world of Nordic flavor opens up to me: thickly spread juniper-seaberry skyr complements the tangy crushed aniseed in my yeasty crispbread, and is topped off by the oily, delicious flavor of gravlax or the crisp spicy crunch of a slice of pickled cucumber.