Viili – the Finnish (Scandinavian) alternative for yogurt
Viili (Finnish = viili, Swedish = filbunke, Filmjölk) is a type of viscous fermented milk product originally from Scandinavia with a velvety, somewhat slimy consistency. It is prepared not just in Finland, but also in Sweden, Norway, and other Nordic countries. Viili was historically made on farms in large wooden buckets, but families have also made them in their homes. It has a ropey, gelatinous consistency as well as a pleasantly mild taste.
Just like other types of Scandinavian fermented milk products, viili is made by using mesophilic cultures that can grow without issue at lower temperatures than what is usually required for milk’s fermentation process, under 30-35°C or 85-95°F.
This cultured milk beverage is the result of microbial action between lactic acid bacteria identified in viili, which include the acid‐producing "Lactococcus lactis subsp. Lactis" and "Lactococcus lactis subsp. Cremoris" as well as the aroma producers "Lactococcus lactis subsp. lactis biovar diacetylactis" and "Leuconostoc mesenteroides". Among these mesophilic lactic acid bacteria strains, the slime-forming "Lactococcus lactis subsp. Cremoris" is also prevalent in kefir; however, in this combination, it produces a particular heteropolysaccharide.
The viili is also characterised by the surface-growing yeast-like fungus ‘’Geotrichum candidum’’ found in milk, forming a velvet-like surface on viili. It also contributes to the typical musty aroma of this product.
In addition, most traditional viili cultures also contain yeast strains, such as "Kluveromyces marxianus" and "Pichia fermentans". The production of exopolysaccharides forms the consistency of viili, and it has been claimed to have various functional benefits toward the texture of milk products and the nutritious potential.
Due to the similar lactic acid bacterial strains, many people are confused and find it difficult to differentiate kefir and viili.
Well, the difference mainly comes from the yeast-like fungus "Geotrichum candidum" which is traditionally present in the viili fermented product. The heteropolysaccharide consisting of molecules of more than one sugar or sugar derivative is named "viilian". Villian is similar to a polysaccharide called "kefiran," which is produced by "kefir grains". Also, on a micro level, there is a difference in the formed carbohydrates, particularly the "villain" responsible for the sticky, viscous texture.
The texture, however, is not fully defined as it also depends on the milk used, incubation time, and incubation temperature, which is reflected in the description of the "Long" variants of the Viili as well as the "short" variants.
The short version looks very much like regular yogurt that is found in stores, except having a very mild taste. The long version has a sticky texture, is even elastic, and has a beautiful sweet taste and flavour.
So, if you want to get the intriguing long type of viili, the one that is slimy and slides on the walls of your bowl, making its consumption an adventure you never experienced with fermented milk products before, you will need a starter culture that contains Lactococcus lactis subsp. Cremoris and incubate this mix at a lower temperature.
For more info and step-by-step tutorials, please refer to our website, blog, or forum, watch the other YouTube videos or download the Yogurt App.