Recipes

Viili (Finnish Ropy Fermented Milk)

My favorite of the odd cultured milks, and the one to make if you do not want to build an incubator — it is MESOPHILIC, so it sets on the counter at room temperature with no equipment at all. It is also famously ropy: you can lift it in long unbroken strands, and that is the point of it rather than a fault.

Fermented · Dairy

Viili (Finnish Ropy Fermented Milk)
Prep 5 minutes
Cook 18–24 hours at room temperature
Serves Makes 1 quart
Level Easy

My favorite of the odd cultured milks, and the one to make if you do not want to build an incubator — it is MESOPHILIC, so it sets on the counter at room temperature with no equipment at all. It is also famously ropy: you can lift it in long unbroken strands, and that is the point of it rather than a fault.

Ingredients

  • 1 cup viili culture (from a previous batch or a live starter)
  • 1 quart whole milk, at room temperature

Directions

  1. Key ingredients
  2. Milk, and viili culture — which you must be given or buy live, as with kefir grains.
  3. Do not heat the milk for a maintenance batch. Room temperature is the whole advantage. (For a first batch from a dried culture, follow the supplier’s instructions, which usually do involve heating once.)
  4. Inoculate: Stir the viili from your last batch into fresh milk, or spread it across the surface — traditionally viili is not stirred in, because the surface layer matters.
  5. Cover loosely with a cloth and leave at 70–77 °F for 18–24 hours.
  6. It is done when it has set and pulls in strands from a spoon. A soft velvety bloom on the surface is correct and expected.
  7. Refrigerate, and keep a cup back to start the next batch.

Notes

PROVENANCE. Mine. Finnish immigrants brought viili to Michigan’s Upper Peninsula, which is how it reached me — see the Finnish Table page in the Upper Peninsula section.

WHAT MAKES IT ROPY, and why the surface film is not a problem: viili is cultured by Lactococcus lactis subsp. cremoris — which produces the exopolysaccharides responsible for the ropiness — TOGETHER WITH a mold, Geotrichum candidum, which grows the velvety layer on top. A deliberate mold on the surface of a dairy ferment sounds alarming and is exactly correct here.

MESOPHILIC VS THERMOPHILIC is the distinction worth learning. True yogurt (L. bulgaricus + S. thermophilus) needs about 110 °F and therefore needs an incubator. Viili, matsoni, filmjolk and buttermilk work at room temperature. If you do not want to buy or build a yogurt maker, make one of these instead.

LANGFIL is the Scandinavian relative and is even more spectacularly ropy.

Eaten in Finland with sugar and cinnamon, or with berries, or plain.