Filmjolk, Viili, Piima, Matsoni, Greek yoghurt and cultured buttermilk. Each one is a living culture that, with a little care, renews itself week after week. Here you'll read what sets them apart and how to get started with them at home.
According to an old story, God asked an angel to teach Abraham the secret of fermented milk, and that's how yoghurt came about. Whether that's true I'll leave open, but it does say something about how long people have been letting milk sour into something edible, nourishing and long-lasting.
The yoghurt most people know comes from a factory and is a one-off: you eat it and buy new. Traditional yoghurt cultures work differently. They're living, self-renewing cultures that, with good care and weekly feeding, you can in theory keep growing endlessly. One good culture in the house, and you can make fresh yoghurt with it for years, without additives, stabilisers or thickeners, for a fraction of the shop price.
Mesophilic or thermophilic: the key difference
You can roughly divide traditional yoghurt cultures into two groups, and that determines how you work with them.
Mesophilic cultures like moderate temperatures. You simply leave them on the counter, at room temperature between 20 and 25 degrees, without a yoghurt maker or other heat source. Filmjolk, Viili, Piima and Matsoni belong to this group. That's exactly why they're so popular with home yoghurt makers: you don't need any equipment for them.
Thermophilic cultures like warmth. Greek yoghurt is the best-known example. It needs a constant, higher temperature to thicken, and a yoghurt maker comes in handy for that.
Filmjolk: the mild Swedish culture
Filmjolk is a traditional Swedish fermented milk, and perhaps the most approachable culture to start with. The result is a mild, creamy yoghurt with a soft, almost custard-like texture and a pleasant buttermilk flavour. Many people find it a touch friendlier than ordinary yoghurt: fresh, but not sharp.
Filmjolk is mesophilic, so you make it right on the counter. It works beautifully in dishes that call for buttermilk, and in Scandinavia it's often poured over fresh or frozen fruit. Because the culture works at room temperature, it's ideal for anyone who wants to make yoghurt at home without equipment.
Viili: the Finnish culture with a jelly-like texture
Viili comes from Finland and is instantly recognisable by its thick, almost jelly-like texture. The flavour is mild and slightly sweet. Viili loves cream: make it with semi-skimmed or whole milk with a dash of cream and you get a rich dessert. Thanks to that unusual texture, Viili lends itself well to layered parfaits, or as a replacement for sour cream in baking such as cake, bread and pancakes, where it adds moisture and body.
Piima: light, creamy and Scandinavian
Piima (pronounced pee-ma) is a light, creamy Scandinavian yoghurt that tastes faintly of buttermilk, with a mild, cheesy undertone. It's perfectly suited to a buttermilk-based dressing: add some herbs, a little vinegar and mayonnaise and you have a fresh salad dressing. It's just as good on its own, or with some fruit or fruit juice.
Matsoni: the culture from the Caucasus
Matsoni (pronounced madzoon) is a fermented yoghurt from Georgia, the country in the Caucasus on the Black Sea. It's smooth, creamy and fairly thick, with a mild, slightly sour note. In Japan, where it's mistakenly called Caspian Sea yoghurt, it's poured over cake, salads and fresh fruit, often lightly sweetened with a little honey. Matsoni is rich in minerals and is sometimes linked to the old age some Georgians reach. Matsoni is also mesophilic, so you make it simply at room temperature.
Greek yoghurt: full, creamy and thermophilic
Greek yoghurt is the exception in this list: it's thermophilic and needs warmth. The result is lightly tart, full and creamy. For that familiar thick, Greek texture you mix one part cream with three parts whole pasteurised milk and let it ferment for about four and a half hours in a yoghurt maker. Greek yoghurt is the base for countless dishes, from savoury sauces to sweet desserts.
Cultured buttermilk: the versatile odd one out
Cultured buttermilk is fermented soured milk that's widely used in cooking, for example in bakes like scones to make them light with a pleasant tang. Sometimes people simply drink it, occasionally with a pinch of black pepper. You can use it to make sour cream and other fermented products at home.
How to keep a culture alive
The lovely thing about these traditional cultures is that they renew themselves. The core is simple: each time, you hold back a small part of your fresh yoghurt and use it as the starter for the next batch. A few rules of thumb:
- Work with clean equipment and pasteurised milk, so unwanted bacteria don't get a chance.
- Give mesophilic cultures a calm spot at room temperature (20 to 25 degrees) and let them sit for 12 to 18 hours.
- Feed the culture regularly, ideally weekly, even when you don't need yoghurt for a while.
- Keep a spare portion separately in the fridge, so you can always restart if a batch fails.
Treat the culture well and it will, in principle, stay active indefinitely. That's exactly what sets traditional yoghurt apart from the one-off kind from the supermarket.
Is yoghurt good for your gut?
Whether yoghurt suits you too varies from person to person. The live lactic acid bacteria can support your gut flora, and because fermentation partly breaks down the lactose, many people tolerate yoghurt better than ordinary milk. Our guide to fermented foods and your gut flora covers what to look out for when working out whether it's right for you.
Would you like our guidance in recovering from your gut symptoms? Book a free, no-obligation intro call. We're happy to think along with you. The call lasts 30 minutes: we look at where you stand, what you've tried, and whether our guidance is a good fit. You'll always take something away from it.