Stirring 'reknits' weepy yogurt.

Byline: FOOD DUDE By Lewis Taylor The Register-Guard

Years before Food Dude became the author of a bi-weekly column, he worked in a grocery store.

It wasn't one of those gourmet groceries with an olive bar and a resident cheese steward, and it looked nothing like those super super markets you see today that sell everything but a decent piece of produce.

This was a good old-fashioned market with lettuce stains on the floor and a meat cutter who looked like he was about one rude customer away from going completely ballistic. Almost everybody who worked there chain-smoked, the place always smelled like a rotisserie chicken and Food Dude had to memorize 50 different price codes for the produce section.

Nowadays, there are probably twice that many fruits and vegetables at even the most basic market, and I'm not even sure a grocery store with only eight aisles could exist. It's great to have more good food to choose from, but part of me misses the simplicity of shopping at that little store that offered two brands of everything (generic and premium) and didn't require a club card or home phone number to get the deal of the week.

If you know the PLU code for Roma tomatoes, or if you just want to know the difference between a betty, a buckle, a crisp, a crumble, a grunt and a slump, write to the Food Dude at the address at the end of the column.

Dear Food Dude: I buy Nancy's plain yogurt in the giant tubs. The first time I dip in, the yogurt is creamy perfection, but the following day I find that some liquid has separated and pooled in the excavation site. So, I stir it up and all is well. But here is the spooky part: the separation happens only once. Ever after, the yogurt maintains its restored creaminess. Is it bewitched?

- Mary

Dear Mary: You're not the only one feeling bothered and bewildered by the mysterious yogurt puddle you describe. Nancy's even has an item in the Frequently Asked Questions section of their Web site on the subject. That liquid you're looking at is nutrient-rich whey, which is essentially the water in the milk that was used to make your yogurt, says Nancy Van Brasch Hamren, office manager and namesake of the company.

By dipping your spoon into the tub you're breaking open cell walls and causing the whey to "weep" out of the yogurt, Hamren says. The process is called syneresis, which sounds like the model name of a new hybrid car, but really just means separating the liquid from a gel.

The reason your whey is weeping has to do with the method Nancy's uses for processing its yogurt. The product is "cup set," meaning it is packaged in the tub as a warm liquid without ever being mechanically stirred. The live cultures in the yogurt are responsible for coagulating the milk. This process differs from some yogurt manufacturers who use gelatin, pectin or other ingredients as stabilizers.

So when you go in there with your spoon, you are breaking up the yogurt for the first time and causing syneresis to occur. The reason the yogurt doesn't weep a second time is because, by stirring it together, you've "mechanically reknitted" the yogurt, Hamren says.

To those who have grown accustomed to dumping their Nancy's whey down the drain, Hamren says you're throwing away some highly nutritious goodness. The liquid is filled with all kinds of great-for-you stuff such as minerals, calcium, magnesium and phosphorus. If you're just not that into mechanically reknitting your yogurt, Hamren says you can drop that whey into a glass of orange juice and drink it boilermaker style.

Bottoms up!

Dear Food Dude: My dear Polish mother always told me that a little mold won't hurt you. After all, that's what they make penicillin out of. I always wondered as a child if I should rub it on my wounds. Anyway, when I open that leftover spaghetti sauce in the fridge, or pull out that slice of bread with a spot of mold, is it OK to cut away the furry life form, like we all do with cheese, or should I take it more seriously and toss the whole enchilada, and possibly avoid needing some real penicillin? Please answer soon. I've got a few items that need some immediate attention.

- UB1

Dear UB1: Food Dude has some Polish blood in him, too, so I feel well qualified to answer your question. It turns out your mother was only partly right, says Diane Stadler, a registered dietitian at Oregon Health and Sciences University.

"If you consume something that has mold on it and notice after the fact, is it going to cause you some harm? Probably not. Is it going to help you? Probably not," she says.

Even though a little mold usually won't hurt you, Stadler says it's best to err on the side of caution. The United States Department of Agriculture agrees and says that while some molds are harmless, others can cause allergic reactions and respiratory problems. Some molds produce poisonous "mycotoxins" that can make you sick.

According to the government, you can learn a lot about mold by delving beneath the surface of food to where molds take root. In other words, molds are more than the surface fuzz you see on the top of your marinara sauce. Many molds contain root threads that invade the food it lives on, as well as a stalk that rises above the food and spores that form at the end of the stalks. The roots may be difficult to see and may actually extend deep into the foods.

The question of whether to use or discard moldy food comes down to what kind of food you're eating. In general, harder foods pose fewer risks. The USDA says you should discard the following when mold appears: lunch meats, bacon, hot dogs, leftover meat and poultry, casseroles, cooked grain and pasta, sour cream, yogurt, jam and jelly, soft fruits and vegetables (peaches, tomatoes), bread and baked goods, peanut butter, legumes, nuts, cottage cheese, cream cheese, crumbled cheese, shredded and sliced cheese, and cheeses such as Brie and Camembert that contain molds that are not part of the manufacturing process.

The government says you can eat hard cheeses with mold spots, as well as firm fruits and vegetables (cabbage, carrots) as long as you cut off the mold at least one inch around and below the mold and avoid cross contamination. You can eat hard salami and dry-cured country hams with mold if you scrub the mold off the surface.

Since mold spores from affected foods can spread, you can prevent mold by keeping your fridge clean and by keeping dishcloths, towels, sponges and mops clean. You also can keep the humidity level in your house below 40 percent.

As for your question about penicillin, no, you can't cure an earache by eating moldy bread. While penicillin is found in mold that grows on bread, so are other toxic chemicals that can make you sick. Doctors say penicillin needs to be isolated in order to be an effective antibiotic.

Talk to the Food Dude at www.registerguard.com/blogs/index.php/fooddude. Or, send mail to Food Dude, The Register Guard, P.O. Box 10188, Eugene, OR 97440-2168.