These Noses Know: MWD Tasters Sniff Out Troubled Waters

Times Staff Writer

Stuart W. Krasner carefully decanted the pale liquid, warmed precisely to 25 degrees centigrade, into a plastic cup. Swirling the bright, unassuming little beverage to let the volatile aromas build, he gently lifted the cup's glass lid and sniffed deeply.

Then it was down the hatch, slurping loudly to check for flavor, aroma and maybe even subtle hints of the African clawed frog. One never knows, and in his six years Krasner has sniffed out a lot.

Scribbling notes in silence, he and four other chemists at the table nibbled unsalted crackers before moving on to the final bottle and a consensus taste verdict: "fishy, cardboardy and grassy."

For Californians, this stuff has built fortunes and cities, but chugging it doesn't leave Krasner staggering about the laboratory. It's only good old tap water, the drink of millions. And in this case it was raw reservoir water, destined after treatment for the faucets of about 13 million Southern Californians.

Five mornings a week, the energetic Krasner, 38, leads a panel of tasters that swig water taken from 20 checkpoints in six Southern California counties to the Metropolitan Water District's water quality laboratory in La Verne. The Flavor Profile Panel's tasting job is to make certain that MWD's 200 different chemical and machine tests of 100,000 samples a year are actually assuring a water taste that people want to drink.

Krasner, one of the laboratory's senior chemists, will put any $200,000 gas chromatograph mass spectrometer up against his team's highly honed palates. "That's still not as good as most of our panelists," he said.

Indeed, the panelists can take a slurp and readily tell if the water comes from Pyramid Lake by the Tehachapi Mountains, Lake Skinner near the San Jacinto Mountains or the Colorado River.

"The nose and palate are a highly specialized piece of equipment perfected through long periods of evolution," said panel member Warren Schimpf, 44, a senior chemist at the laboratory with a doctorate from the University of Michigan. "You just can't program a computer to do that."

"They are much faster than even our best mechanical services," said Bob Gomperz, a spokesman for MWD.

And in an emergency, speed and a light suitcase can take panelists where no machine could go.

"When we have a taste or odor emergency at one of our reservoirs or treatment plants, they've been known to stay on site around the clock for days until the problem is solved," Gomperz said.

Panelist Pat Rottler, 44, once found herself bobbing on a boat at Lake Mathews in Riverside County to answer a taste emergency call: rotten, fishy smells. As a team of scuba divers gathered samples at different lake levels beneath her, Rottler calmly slurped the test tubes of water they brought to the surface. Turned out some algae was acting up, but nothing a little chlorine couldn't fix.

Frog Infestation

Several years ago, African clawed frogs infested the San Joaquin Reservoir. But panel members never could find any aromatic hint of the unwanted amphibian, Krasner assured a questioner.

MWD formed the panel in August, 1981, with the help of a Cambridge, Mass.-based consulting firm that trains food and beverage tasters for chocolate companies, perfume manufacturers, wineries and even a whiskey distillery in Ireland. The district had found its previous tasting test too subjective.

For Krasner and his tasting colleagues, otherwise occupied as full-time chemists and analysts, the sniffing and slurping is just a part-time job at the laboratory.

No Spitting Here

As opposed to the sniff-and-spit technique preferred by wine tasters, the panel follows the sniff-and-swallow method.

Bitter taste buds are in the back of the mouth, and some odors can only be perceived just shy of the esophagus, explained Krasner, the panel's senior member. "What we technically call flavor is actually an odor," he said.

In a world full of offending odors, care is taken by the tasters.

Whenever the lawn surrounding the laboratory outside is mowed, for example, all tasting is off that day. "All you can smell is grass," sniffed panelist Sylvia Barrett, 44.

A recent visitor was asked politely to leave his coffee outside the tasting room, and an accompanying photographer was greeted by Krasner with a shrill, "Is that perfume I smell?"

Rottler, credited by her colleagues as the most acute taster on the panel and the only one to drink bottled water at home, won't return to one unnamed restaurant because of an unfortunate water experience. "The chlorine was so strong you could wash your clothes in it," she said.

Unmemorable Taste

Asked to describe good-tasting water, the panel was momentarily stumped, and then offered terms like "refreshing." Barrett finally summed up: "If you don't remember it, that's a good sign."

Although most of the panel had been to San Francisco, no one could remember its water, apparently a good sign for Bay Area drinkers. A recent sample of Boston water shipped to the lab, however, was hooted down. "Uggghh, it tasted like cucumbers," Rottler said. "They were having trouble with algae."

Don't even mention Philadelphia water--"musty, chlorinous and chemical," Krasner said. "There's a lot of industry on the Delaware River."

Krasner is proud of MWD water, all of it drawn from Northern California and the Colorado River. "We are low in iron and stuff that causes a metallic taste," he said. "It's delicious."


Like every profession, the water tasters who work for the Metropolitan Water District have their own lexicon. Here are some of the tasters' terms for problem water.

CHP officers who saturated freeways in Los Angeles, Orange and San Diego counties arrested 586 suspected drunk drivers, said Officer Charlotte Foley.

Cardboard or rubber: Cause unknown, but chlorine rids the water of the taste.

Grassy: Caused by hexenol, nicknamed leaf alcohol, which occurs in all green plants

Musty-moldy: Caused by 2-methylisoborneol, an algae byproduct every fall and summer. People can taste 5 parts per trillion.

Swampy: Caused by dimethyltrisulfide at certain concentrations, which smells like garlic or onions and results from a breakdown of proteins of algae.

Swimming pool: Caused by bichloramine, same cause as above.

Watermelon, melon or cucumber: Caused by nonenalfrom from algae.

Dry mouth: Water high in dissolved solids and minerals.

Fishy: Water with a rotten, fishy smell caused by trimethylamine, a breakdown of algae proteins.

Geranium: Water with trichloramine, occasional byproduct from mixing of chlorine and ammonia to treat water.

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