Filmjölk facts for kids

Filmjölk in a glass.

Filmjölk (say "film-yolk"), also known as fil, is a popular fermented milk product from Sweden. You can find it in many Nordic countries. It's made by letting cow's milk ferment with special bacteria. These bacteria are from the Lactococcus lactis and Leuconostoc mesenteroides groups.

The bacteria eat the lactose (milk sugar) and turn it into lactic acid. This means people who are lactose intolerant might find it easier to digest than regular milk. The acid also gives filmjölk a slightly sour taste. It makes the milk's proteins thicken, creating a creamy product. The bacteria also make a tiny bit of something called diacetyl, which gives filmjölk its unique buttery flavor.

Filmjölk has a mild, slightly sour taste. It usually stays fresh for about 10 to 14 days if kept cold in the fridge.

What is Filmjölk?

In Nordic countries, people often eat filmjölk for breakfast. They might add cereal, muesli, or crushed crisp bread on top. Some like to add sugar, jam, apple sauce, cinnamon, ginger, fruits, or berries for extra flavor.

In Norway, it's called surmelk or kulturmelk. In Latvia, it's known as rūgušpiens. In Lithuania, it's called rūgpienis. People in these countries often make it at home, but you can also buy it in stores.

How Filmjölk is Made

Most filmjölk you buy in stores is made from cow's milk that has been pasteurized (heated to kill germs), homogenized (mixed so the fat doesn't separate), and standardized (adjusted to a certain fat content).

People have been making filmjölk at home for a very long time, possibly since the Viking Age. But it first became a product you could buy in stores in Sweden in 1931. A dairy company called Arla started selling it. The first filmjölk was plain and had 3% milkfat.

Over the years, many different kinds of filmjölk have appeared:

• In 1965, Långfil was introduced. This is a more stretchy type of filmjölk.
• In 1967, lättfil came out, which is a lighter version with only 0.5% milkfat.
• In 1990, mellanfil was launched, with 1.5% milkfat.
• In 1997, Arla made its first flavored filmjölk – strawberry! It was so popular that many other flavors soon followed. By 2001, almost one-third of all filmjölk sold in Sweden was flavored.

Today, you can find filmjölk with different fat levels, flavors like fruit, vanilla, or honey. There are also types with probiotic bacteria, which are good for your health. For example, Onaka fil has a special bacteria from Japan, and Verum Hälsofil has a lot of Lactococcus lactis L1A bacteria.

Filmjölk in English

There isn't one perfect English word for fil or filmjölk. People have tried calling it sour milk, fermented milk, or curdled milk. These words describe it, but they don't show how filmjölk is different from other similar products. Sometimes, you might see articles in English that just use the Swedish word filmjölk or filmjolk.

If you're baking and a recipe asks for filmjölk, you can often use cultured buttermilk instead.

Filmjölk in Finland

In Finland Swedish, which is the Swedish spoken in Finland, fil means something similar to filbunke in Sweden. Not all types of filmjölk found in Sweden are available in Finland. The most common ones are filbunke and långfil. Swedish speakers in Finland often use the word surmjölk (which is an older name for filmjölk) or piimä. Piimä is another fermented milk product, but it's thinner and more like cultured buttermilk.

Different Types of Filmjölk in Sweden

In Sweden, several dairy companies make filmjölk. Before it was made in factories, many families made it at home.

The special bacteria used to make fil are from the Lactococcus lactis and Leuconostoc mesenteroides groups. For example, Arla's fil culture includes different types of Lactococcus lactis and Leuconostoc mesenteroides.

Classic Filmjölk Varieties

• Filmjölk: This is the "regular" kind, usually with 2.5% to 3% milkfat. It comes plain or flavored. You can also find organic versions, low-lactose versions, and some with added fiber. This type of filmjölk has been known in Sweden since 1741.
• Mellanfil: This means "middle lowfat filmjölk." It has about 1.3% to 1.5% milkfat and usually comes plain. It was introduced in 1990.
• Lättfil: This means "light (nonfat) filmjölk." It has very little fat, around 0.4% to 0.5%. It comes plain or flavored, and there are also low-lactose versions. It was introduced in 1967.
• Långfil: This means "long fil." It has a unique, stretchy texture because of a special bacteria called Lactococcus lactis var. longi. This bacteria turns milk sugars into long chains that make it elastic. It usually has 3% milkfat and comes plain. It's more common in northern Sweden and sometimes eaten with ground ginger. This type has been around since 1896.
• Bollnäsfil: This filmjölk comes from the town of Bollnäs. It has 3% milkfat and can be plain or vanilla-flavored.
• Fjällfil: This means "fell fil." It has a special fil culture and comes plain, with birch sap, or raspberry flavor.
• Filbunke: This means "bowl of fil." It's milk that has fermented without being stirred, often in small bowls. It has a pudding-like texture. Traditionally, it was made from raw milk, which would form a yellowish layer of sour cream on top. It comes plain or flavored and has been known since 1652.
• Laktosfri fil: This is "lactose-free fil." It has 3.5% milkfat and is treated with a special enzyme to remove lactose. It comes plain.

Filmjölk with Probiotics

Some filmjölk products contain extra probiotic bacteria. These are good bacteria that can help your digestive system.

• A-fil: This filmjölk contains Lactobacillus acidophilus, a common probiotic. It comes with different fat levels, plain or flavored, and in low-lactose versions. It was introduced in 1984.
• Cultura aktiv fil: This has Lactobacillus casei F19, a special probiotic bacteria. It has very low fat (0.1%) and comes plain.
• Kefir: This filmjölk is based on kefir, another probiotic food. It contains some of the good microorganisms found in kefir grains. It has 3% milkfat and comes plain. Kefir originally came from the Caucasus region.
• Onaka: This means "stomach" in Japanese. It contains Bifidobacterium lactis, a probiotic popular in Japan. It has 1.5% milkfat and comes plain or flavored.
• Philura: This filmjölk tastes like a mix between regular filmjölk and yogurt. It has probiotics like Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus casei. It comes with different fat levels, plain or flavored.
• Verum hälsofil: This means "Verum health fil." It contains a lot of Lactococcus lactis L1A bacteria. It comes with different fat levels, plain or flavored. This special bacteria came from a långfil culture in northern Sweden. It's been shown to help the immune and digestive systems.
• Öresundsfil: This filmjölk contains Lactobacillus acidophilus and Bifidobacterium probiotics. It comes with different fat levels, plain or flavored.
• ProViva Naturell Filmjölk: This plain filmjölk contains Lactobacillus plantarum 299v. This probiotic has been shown to help with digestive issues.

Making Filmjölk at Home

To make filmjölk at home, you usually take a small amount of already made filmjölk (which has the bacteria) and add it to pasteurized milk. Then, you let it sit for a day or two at room temperature or in a cool place. You need to add the fil culture because the natural bacteria in milk are killed when it's pasteurized.

Tätmjölk

A special type of filmjölk is called tätmjölk. To make it, you rub the inside of a container with leaves from certain plants, like sundew (Drosera) or butterwort (Pinguicula). Then, you add lukewarm milk and let it ferment for a day or two. You can then use some of this tätmjölk to make more.

Carl von Linné, a famous scientist, described how to make tätmjölk in 1737. He said any type of butterwort plant could be used. Both sundew and butterwort plants are carnivorous plants. They have special enzymes that break down proteins, which helps the milk thicken. Scientists are still studying exactly how butterwort helps make tätmjölk.

See also

In Spanish: Filmjölk para niños