"No way!" she said.

Funny she should say that, because "no-whey" yogurt - the unflavored version drained for a minimum of four hours - is a key component of one of her favorite pasta dishes.

To millions of American children, yogurt is a fact of life - and dessert. Rather than knowing it as an ingredient, they think it edible only if it contains added sugar in the form of flavorings, fruit, cereal, or even bits of candy.

In the olden days, before the American marketplace pumped it full of such things, yogurt was a happy, healthy, calcium-rich union of certain bacteria and milk that originated in the truly olden days of the Neolithic period in Central Asia. It then was popular in ancient Greece, Rome and Egypt - and still is. (Tzatziki, the yogurt-garlic-dill dip, has a widespread modern following, for example.)

In the United States, though, yogurt began to infiltrate the refrigerators of everyday Americans only in the 1970s. Before that it was identified with immigrants, then with hippies living off the grid in California.

But even before yogurt was groovy, enterprising new Americans Sarkis Colombosian and his wife, the former Rose Krikorian, saw that it could be profitable.

In 1929, the couple began what is now our robust yogurt culture by founding the nation's first yogurt manufacturing plant, Colombo & Sons Creamery, at their small farm in Andover, Mass.

Their product, full-fat and non-flavored, was based on Rose's traditional recipe from Turkish Armenia, the immigrants' home country. At first, it sold only to European transplants familiar with its taste and virtues. But by 1940, according to the Massachusetts Historical Society, it was selling well throughout New England.

Over the years the company grew, expanded its offerings, and soon had to compete with the product of another immigrant, Daniel Carcasso from Portugal, whose company, Danone (now Dannon), pioneered fruit-flavored yogurt in 1947. (Dannon is the world's top-selling brand. The Colombosian family sold its company in 1993 to the General Mills conglomerate.)

Now yogurt is as ubiquitous a refrigerator item as milk - be it plain, laced with fruit jam and/or cereal and/or candy, frozen like ice cream, packed into tubes, carbonated to attract more tweens, and, just recently for baby boomers, marketed as a "probiotic" aid to digestion and the immune system. There are pet snacks covered in it, skin conditioners and make-up containing what purports to be yogurt; it's an ingredient in toothpaste and cereal.

All of which is why U.S yogurt sales doubled to $5 billion from 1998 to 2006, according to the market tracking company Euromonitor.

Shopping for yogurt requires a glossary: Swiss or custard style is mixed with fruit; sundae-style has fruit on the bottom; probiotic means it contains bacteria friendly to the digestive system.

But my favorite type of yogurt is the triple-strained, thick, unflavored Greek style, which, happily, is also becoming more available. (Look for the Chobani, Fage and Oikos brands.)

However, since purchasing a yogurt strainer, a strange-looking, conical footed contraption made of white plastic and fine plastic mesh, I discovered that supermarket brands (but not the type that contain gelatin) can be drained to produce similar yogurt - sweet and creamy with consistencies ranging from thicker to cheeselike.

As many people of Middle Eastern descent know, it is delicious eaten cold, perhaps with a drizzle of honey and figs in season, among other ways.

It is also an excellent ingredient, but remember:

Bring it to room temperature before including it in a hot dish so that it does not separate.

Don't boil anything containing yogurt. Heat the mixture gently just until it is warm or it will curdle nastily.

Don't heat it to more than 120 degrees if you want to preserve its beneficial bacteria. Stirring it in at the end of a cooking process is best.