Heirloom Yogurts as Kitchen Companions: Matsoni, Piimä, Viili & Filmjölk
Yogurt is one of those quiet miracles of the kitchen, a jar of milk transformed by time, and the presence of unseen companions. Most of us meet yogurt in its thermophilic form, coaxed by heat into a thick, tangy cream. But there’s another slower and more subtle lineage of soured milks that thicken at room temperature.
These are the heirloom mesophilic yogurts, or soured milks including matsoni from the Caucasus mountains, piimä and viili from Finland, and filmjölk from the deep forests and rolling hills of Sweden. Each is a culture of patience, stirred into fresh milk and left to dream into being overnight. They don’t ask for special equipment or heat, only the steady rhythm of tending: a spoonful saved, a jar replenished, a cycle that binds you to kitchens and hearths far older than your own.
The Cultures
Matsoni
I began with a matsoni starter from Cultures for Health. After carrying the waiting culture home from the local fermentation store, I took the small packet and I whisked it into a jar of milk. Within a day the milk thickened slightly and while nourishing and tasty, it was on the third batch that the yogurt took on a soft velvety texture that was the perfect pairing for fresh strawberries. Cultures for Health provides clear instructions, which makes it easy for those new to fermented milks to enter this ritual.
Piimä
My piimä starter came, along with the matsoni, in the heirloom yogurt sampler from Cultures for Health, tucked in a small, carefully wrapped envelope. The first jar set into a light drinkable yogurt similar in consistency to kefir, sweet and mild, with the faintest buttery aroma. Piimä offers creaminess without weight a comfort in the winter and refreshing on warm days. It can also be used to culture cream to accompany savory dishes or to be turned into butter, another slow, kitchen ritual.
Viili
Viili, also from Cultures for Health, feels like an enchantment. Spoonfuls stretch and cling with a playful, wild, ropiness, and a clean tang that lingers on the tongue. It’s one of the most distinctive yogurts to tend, a culture that makes its presence known as soon as you lift the lid. But Viili can also mellow over time as different bacterial strains flourish and wane, so its ropiness may subside over time.
Filmjölk
For filmjölk, I turned to Cultures for Health again. The starter yielded a yogurt with a slightly pourable consistency, silky and light, somewhere between kefir and custard. Its taste is gentle, with a faint brightness that pairs beautifully with berries, granola, or a drizzle of honey.
How to Choose the Right Culture
- For a spoonable, mild all-purpose yogurt: Matsoni will take its place in your morning ritual.
- For a mild, drinkable option: Piimä with a subtle cheesy flavor in a bowl or in a glass.
- For pure magic on a spoon: Viili, with its playful, ropy texture.
- For a gentle, buttery classic: Filmjölk, or one of the many other varieties of fil yogurts sold by Positively Probiotic.
Where to Find Cultures
Local Sources
- Fermentation groups and swaps: Many communities have fermentation circles or food swaps where heirloom yogurt cultures are shared freely. I imagine that a mason jar of Viili passed hand to hand feels like real magic, although I have not yet had the good fortune to participate.
- Farmer’s markets and co-ops: Ask local cheesemakers or small dairies as sometimes they may be willing to share or sell a culture. Farmer’s markets can be good sources for robust thermophilic varieties, however mesophilic yogurts are rare.
- Workshops and classes: Fermentation classes are places of sharing and gathering, places for the community that will often send you home with a jar of culture tucked in to your bag.
Mail Order
Small businesses that cultivate and share heirloom yogurt are good places to find the more common and even some unusual varieties:
- Cultures for Health – If you are new to caring for cultures, these are widely available and come with clear instructions for how to bring yogurt into the rhythm of your kitchen.
- Positively Probiotic – Small-batch and artisan bringing less common cultures to your hearth.
- Northwest Ferments – A community of fermenters with strong, heirloom cultures for you to tend. Yogurt made with their Greek Yogurt starter has become a weekly ritual in my kitchen.
Caring for Your Culture
- A Recipe: To learn to tend your culture.
- Milk matters: The richness of whole milk supports the soft, often velvety texture of mesophilic strains. Ultra pasteurized milks can weaken the culture over time.
- Timing: Tending the lineage of matsoni, piima, or viili take time and patience. Add a spoonful of milk to a jar and wait quietly for up to a day, observing the temperature and the time it takes for the milk to thicken. You will learn the rhythm of each culture with time.
- Re-culturing: Heirloom yogurts can be tended for generations if tended with care. Always save a few spoonfuls of your finished batch to start the next one. And keep a few spoonfuls of your culture stored in your freezer to ensure that you can experience the magic of yogurt in your kitchen for years to come. Refresh your frozen cultures every six months to keep them active.
Closing Reflection
To keep mesophilic yogurts is to enter into a practice of tending, saving, and renewing. Each jar becomes a link to invisible kin that thrive through care and the lineage of those who tended the culture before you. What begins as milk and culture becomes something more. It is inheritance, ritual, and daily magic, a way to nourish not just the body but the link between past and present, home and heart.
