How to make piimä at home?

How do you make piimä at home?

Piimä is Finnish cultured milk made with mesophilic bacteria, which means it ferments at ordinary room temperature and needs no yogurt maker. The steps below follow a published guide to the traditional method. Times vary with your room, your culture and your milk.

What do you need?

• A clean glass jar and a cloth or paper cover so gases can escape
• Milk (whole milk gives a creamier result)
• A piimä starter culture, or 1 tablespoon of fresh piimä from a previous batch for each cup of milk

Step by step

1. Wash the jar and utensils well with hot soapy water.
2. Pour in the milk and stir in the starter. The guide uses about 1 tablespoon of starter per cup of milk, and recommends the freshest piimä you have.
3. Cover loosely and leave it undisturbed at about 70 to 77 degrees F (21 to 25 C).
4. Wait 12 to 18 hours. Cooler rooms take longer. If the room drops below 70 F overnight, move the jar somewhere warmer.
5. It is ready when the milk has thickened into a compact mass that comes away from the wall of the jar.
6. Stir it, then chill it in the refrigerator for about 6 hours before eating or drinking, which firms up the culture.

How do you keep it going?

Save a few tablespoons of each batch as the starter for the next one, and use it while it is fresh. If a batch smells rotten rather than pleasantly sour, shows pink, orange or fuzzy mold, or the texture is wrong, throw it out and start again with a new culture. Do not guess.

What affects the result?

• Warmth: cooler rooms take longer, so keep the jar within the 70 to 77 degrees F range.
• Milk: whole milk gives a creamier result; follow your starter’s instructions for other types.
• Cream: the same culture can be used with cream for a thicker result like sour cream.

How do you serve it?

Drink it plain, add a pinch of salt in hot weather, or use it as a dressing or breakfast topping. Always keep it refrigerated once it has set.