Viili substitute

Best substitute

Filmjolk

Use the same amount by volume as the viili you are replacing

Best for breakfast bowls with sugar and cinnamon

Different texture

Be warned up front: nothing you can buy will match viili's stretch, because that long ropy pull comes from the specific Lactococcus strains in the culture and no ordinary yogurt has it. The closest available product is Swedish filmjolk, used 1:1. After that, matsoni or Caspian Sea yogurt is mild and slightly viscous in a similar way. If you are baking with viili rather than eating it, plain yogurt or buttermilk 1:1 does the job perfectly, because the batter only wants the acid and the liquid.

Other viili substitutes

Ranked, with the exact amount to use

2Matsoni (Caspian Sea yogurt)
Close match
Use the same amount by volume
A Georgian-style yogurt also cultured at cool room temperature, mild and faintly viscous rather than sharp.
What changes
Best for
breakfast bowls, drinking thinned with milk, baking, chilled soups off the heat
Genuinely close on flavor, which is the mild lactic sweetness both share, and it has a slight honey-like stickiness that hints at viili's texture without ever reaching real ropiness. Slightly thicker and a touch tangier than viili. Home fermenters will find this the easiest swap to actually keep going, since like viili it cultures on the counter with no incubator.
3Plain whole-milk yogurt
Taste and texture differ
Use the same amount thinned with 1-2 tablespoons milk per cup if needed
Ordinary unsweetened set yogurt, the swap most people will actually reach for.
What changes
Best for
baking, breakfast bowls, marinades, dressings and dips
Works, with two clear differences. Yogurt is distinctly more sour than viili because it is cultured warm with different bacteria, so a bowl eaten plain tastes tart where viili tastes almost sweet; a spoonful of sugar or a drizzle of honey closes most of that gap. And it is smooth and spoonable rather than stretchy. In any batter or dough the substitution is invisible.
4Buttermilk
Taste and texture differ
Use the same amount by volume
Cultured pourable milk that supplies exactly the acid viili brings to baking, and nothing like its body.
What changes
Best for
pancakes and waffles, quick breads and muffins, Finnish soured-milk baking, cold soups
For any recipe where viili is an ingredient rather than the dish, this is the cheapest and most reliable option. It is acidic to the same degree, so baking soda behaves the same and you get the same rise and tender crumb. It is far too thin to eat with a spoon and it tastes saltier and sharper than viili, so keep it in the mixing bowl.
5Kefir
Taste and texture differ
Use the same amount by volume
Fermented milk cultured with both bacteria and yeasts, giving it a sharper flavor and a faint natural fizz.
What changes
Best for
drinking, smoothies, baking, marinades
The furthest from viili in character of the fermented options here. Where viili is mild, thick and slightly sweet, kefir is thin, sour and yeasty with a prickle on the tongue. It is a fine soured milk for baking and a good drink, but if you serve it as viili to someone Finnish they will notice immediately. Cut it half and half with plain yogurt to tone it down.
6Sour cream thinned with milk
Different taste
Use ½ cup sour cream plus ½ cup milk for every cup of viili
Cultured cream diluted to viili-like thickness for use as a sauce or topping.
What changes
Best for
cold sauces and toppings, spooning over potatoes or fish, desserts
Comes out smooth and gently tangy, closer to viili's mildness than yogurt is, but much richer, since sour cream is around twenty percent fat against viili's three or four. Dishes finish heavier and coat the mouth more. Good when viili is enriching something, wrong when it is meant to be a light breakfast.

What is Viili?

Viili is a Finnish soured milk cultured at room temperature that sets into a very mild, barely tart curd with a famously ropy, stretchy pull, usually capped by a thin velvety skin from a surface mold that grows alongside the bacteria, and in Finnish baking its job is simply to be the liquid and the acid a batter needs.

Cooking tips

Decide first whether you want viili's flavor or its texture. The mild taste is easy to copy with filmjolk, matsoni, or yogurt plus a little sugar. The ropy stretch is not copyable with anything on a supermarket shelf, and no amount of stirring or thickener produces it.
Do not stir any viili substitute hard. Viili is served as an intact set curd that you break with a spoon, and whisking yogurt or filmjolk smooth turns it into a drink and loses the point.
Serve it the Finnish way and the swap matters less: a dusting of cinnamon and sugar, or ground ginger, over a cold bowl. The topping is loud enough to carry a slightly tarter base.
If you are keeping a home culture, viili is mesophilic, so it sets on the counter at normal room temperature over about a day and needs no yogurt maker. Matsoni and filmjolk behave the same way, which makes them the natural swaps for a hobbyist; a regular yogurt culture will not work at those temperatures.
Viili is often labeled with its surface mold, Geotrichum candidum, which forms the thin velvety skin on top. That is normal for viili. Fuzzy, colored or bad-smelling growth on any of these substitutes is not, and anything that smells bitter, yeasty in a solvent-like way, or genuinely rotten should be thrown out rather than tasted.

Frequently asked questions

Why is viili stringy, and can I make a substitute stringy?

The ropiness comes from long-chain sugars that particular strains of Lactococcus lactis produce as they ferment, and it is a property of the culture rather than something you can add. Cornstarch, gelatin and gum thickeners make a substitute thicker but never stretchy in the same way; they read as gluey rather than elastic. If you need real viili texture, the only route is obtaining a viili culture and making it.

Is viili the same as filmjolk or ymer?

They are cousins. All three are Nordic mesophilic soured milks, cultured at room temperature and much milder than yogurt. Filmjolk is Swedish and smooth, ymer is Danish and has some whey drained off so it is thicker and higher in protein, and viili is Finnish and ropy. Filmjolk is the closest stand-in for viili, and ymer works if you do not mind extra body.

Can I just leave viili out of a recipe?

Only if you replace what it was doing. In Finnish baking it is the liquid and the acid, so omitting it leaves the batter dry and flat, and any baking soda unreacted and slightly soapy tasting. If you have no soured dairy at all, use milk plus a tablespoon of lemon juice per cup and rest it ten minutes. If viili was the dish itself, there is nothing to leave out.

Can I use Greek yogurt instead of viili?

You can, but thin it. Greek yogurt is strained, so it is far thicker than viili and considerably more sour. Whisk in milk until it slumps rather than stands, about a quarter cup of milk per three quarters cup of yogurt, and add a little sugar or honey if you are eating it plain. In baking, thin it the same way so the batter hydrates properly.

Where do I buy viili?

Finnish and Nordic grocers sometimes carry it fresh, and home-fermentation suppliers sell heirloom viili cultures that you keep alive by reculturing a spoonful into fresh milk. Ordinary supermarkets outside the Nordics do not stock it, which is why filmjolk, matsoni or plain yogurt are the realistic answers.

Related substitutes

More dairy substitutes

Viili substitute

Other viili substitutes

2Matsoni (Caspian Sea yogurt)

3Plain whole-milk yogurt

4Buttermilk

5Kefir

6Sour cream thinned with milk