Långfil (also known as long milk) is a kind of sour milk requiring low souring temperature and long maturation. It has a mild acidity, and texture is chewy almost bubbly like a whipped desert. The bacterial culture consists primarily of Lactococcus lactis ssp cremoris who put together the milk carbohydrates for long exopolysaccharides, which leads to the texture.
In the absence of bacterial culture, you can also make long milk using leaves from butterwort or sundew. These plants have enzymes that can break down the milk proteins and make it thick. Today, however, some people believe that there are bacteria that are common to these plants, which makes the milk long, others suggest the culture is still present in traditional wooden bowls used to make it. Either way it's delicious, and something we may consider selling locally in the future.