Why People Strain Yogurt

Straining is one of the oldest ways to change yogurt. Hung in a cloth or spooned into a sieve, yogurt slowly loses its watery whey and becomes thicker, richer and tangier. The idea is so simple that it appears again and again, in different places, under different names. This article looks at why people strained yogurt, what the practice has been called, and what changes when the whey goes.

A practical tradition

In many food cultures, straining was a practical choice. Whey is mostly water, and removing it leaves a more concentrated food that is easier to carry, to season and to use in cooking. Traditions of storing strained yogurt, for example shaped into balls and dried, or kept under oil, are widely described. Exact histories are hard to date, and these methods belong to their home kitchens and climates, so treat them as part of food heritage rather than as instructions to copy.

Many names, one idea

Strained yogurt goes by many names. In the Levant and wider Middle East the soft, spreadable version is labneh. In Turkish cooking you will meet süzme yoğurt, "strained yogurt". South Asian kitchens make chakka, which is the base for sweet dishes such as shrikhand. Iceland's skyr is a cultured dairy food made with similar straining. The details differ, and so do the milks and cultures, but the shared principle is the same: let gravity take some of the liquid away.

What straining changes

Whey carries water, some milk sugar and minerals. When it drains, the milk proteins that remain become more concentrated, so the yogurt feels thicker and denser, and many people find the flavor tangier. Food standards recognize the difference: the international Codex standard for fermented milks describes concentrated fermented milks, including strained yogurts, as products whose protein has been raised to at least 5.6 percent. That is a regulatory description rather than a recipe, but it shows how much more concentrated strained products are than ordinary set or stirred yogurt.

Using the whey

The liquid you drain off is not waste. It is tart and thin, and cooks have long used it in place of some of the water in bread dough, pancake batter, soups and smoothies. Because it is a dairy product, treat it like milk: keep it cold, use it promptly and let your eyes and nose tell you when to throw it away.

Strained yogurt is simply yogurt with some of its whey drained away.

What cooks have learned

Home cooks have a few reliable observations. Different cloths and different base yogurts drain at different speeds, and sources disagree about how long it takes to reach a given texture, so judge by the look and feel of the yogurt rather than by the clock. Weighing the yogurt before and after gives you a number you can repeat next time. Straining in the fridge keeps the yogurt cold throughout. Squeezing the cloth can make the result grainy, so let the whey drip. The Strained Yogurt guide in the Make tab covers the method in detail.

A small step, a different food

Strained yogurt shows how a small change in handling can create a different food. A bowl of thick yogurt for breakfast, a spreadable labneh for flatbread, a rich base for dips: all start from the same jar, and all depend on the same patient step of letting the whey go.