Without any special equipment, the traditional Finnish dairy product viili is surprisingly easy to prepare at home. The recipe below describes the way my grandmother Maila taught me to prepare it.

However, to be able to produce viili, you will need to have a previous batch of viili at hand to be used as a "seed" for the next batch, or you will have to know where to purchase the viili "seed". Outside Scandinavia, this may be a problem. At least in the U.S.A., a company called G.E.M. Cultures is selling the special starter bacteria culture, which is needed to turn ordinary milk into viili.

Read more about viili here.

Kermaviili is another popular Finnish curdled cream product which is possible to produce without any other starter bacteria culture than that found in regular buttermilk. Read more about kermaviili here and see a recipe for it here.

4 - 6 tbsp fresh Finnish viili
about 600 ml milk (preferably whole milk)

If you do not have access to fresh viili and are using store-bought viili culture, follow the manufacturer's instructions received with the package. In Finland, regular fresh viili is mostly available in 200-gram cup packages. It can be found sold in virtually every grocery store.

You may use any type of regular, pasteurised milk (homogenised, unhomogenised, low-fat, nonfat, low-lactose etc) for making viili, but using whole milk will give the best result. Bring the milk almost to the boil, but do not let it boil. Take it off the heat and let it cool until its temperature is about 22 °C (normal room temperature). The starter culture bacteria work more efficiently in a warm environment.

Open the viili package. Gently skim off some of the thin, velvety layer of yellowish-white cream on the surface of viili, exposing the white part below. (The creamy top layer is regarded as the most delicious part of the viili, so by all means, eat it!) Scoop out a few tablespoons of viili right from the surface, just below the cream layer. Take a few thoroughly clean and dry small cups or dessert bowls and place a tablespoon of viili in each of them. Eat or discard the leftover part of viili in the package.

Pour about 100 to 150 millilitres of the previously warmed and cooled milk in each cup, on top of the viili. Cover the bowls loosely with a clean tea towel or pieces of paper towel. Place the covered bowls in a non-drafty place, for example inside the cold oven, closing the oven door.

It takes about 24 hours for the viili to develop. It is ready, when the milk has thickened and set. Cover the viili bowls tightly with plastic and chill them in refrigerator before eating. Serve viili for breakfast or as a healthy snack between meals. Viili will keep for a couple of days in refrigerator. Save some of the viili for making the next batch.

Serving suggestion:
A popular way to eat viili is to sprinkle it with a dash of sugar and powdered cinnamon. Besides this, it may be served with virtually anything, from fresh fruit and berries to muesli, honey or jams. Try viili with gooseberry jam. Ready-made gooseberry jam of pretty good quality can sometimes be found sold in some Swedish IKEA stores.

Note that it is very important not to stir viili, as this will mix the watery bottom and the creamier, firmer top layers, making viili lumpy and unpleasant to eat. Viili container must always be stored or transported in an upright position, unshaken, for even just slighty tilting it will ruin the consistency  —  a fact too often ignored by many cashiers (mis)handling viili packages at the grocery store check-out counter :-)

Recipe source: family recipe/traditional Finnish recipe.