Science has validated what every grandmother knows: Celery makes chicken soup taste better. Tasting the stringy vegetable isn’t necessary to enjoy its flavor-enhancing attributes. Tasteless compounds that are captured by the nose actually boost the broth’s flavor, Japanese scientists report.

The researchers had previously dissected celery’s odor, zeroing in on the compounds that give the vegetable its characteristic smell. In the new study, the scientists selected four of these compounds, known as phthalides, to determine which ones intensified the complex flavor of chicken broth.

Kikue Kubota and colleagues boiled celery, separating the evaporated components from the solid. Then the team added each component, in concentrations too low to smell, to samples of broth. Ten female panelists, who were screened for satisfactory olfactory and gustatory skills, tasted the doctored broth and broth alone. They also sampled broth with each phthalide added, also in concentrations too low to detect by smell. Panelists then repeated several of the tests while wearing nose clips.

The evaporated fraction of the celery, which had no taste, enhanced the chicken broth’s flavor significantly more than the solid residue did, the researchers report in the Jan. 23 Journal of Agricultural and Food Chemistry. And three of the four phthalides bumped the broth’s flavor up a notch, but this boost wasn’t detectable to panelists wearing nose clips. So take that clothespin off your nose and finish your soup.

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