How we tested

Israeli couscous, a round semolina pasta about the size of tapioca, provides wheaty flavor and pleasantly chewy starch to soups, salads, and pilafs. Distinct from the tiny, grain-like North African couscous, Israeli couscous, which originated in 1950s Israel as a substitute for rice, is larger and springier, with round, pale grains that earned it the alternative moniker of “pearl” couscous. We tasted five supermarket products, plain and in our recipe for our Cook's Illustrated Israeli Couscous with Lemon, Mint, Peas, Feta, and Pickled Shallots (see related content).

Cooked according to package directions, most passed muster with our tasters, but one product was a mushy mess. Its directions demanded almost twice the usual quantity of water and had us boiling it far longer than the others. To level the playing field, we tasted all the products again, this time using our preferred pilaf cooking method (toasting the grains in olive oil and then adding water and simmering until the couscous absorbs the liquid). This time all the products got passing grades, but one stood out as a bit better than the rest: Tasters found it especially firm and springy, chewy, and nutty.

What made the difference? We found our answers by examining the nutrition labels. Our recommended products contain about 15 percent protein relative to total carbohydrates, while the lowest-ranking product has about 13 percent. It turns out that this minor-sounding difference is significant in determining whether the couscous cooks up firm and chewy or turns into a mushy mess. Protein holds the carbohydrates together like an adhesive, so characteristics such as chewiness, texture, and resistance to breakdown when liquids are added (and during cooking) are all strongly influenced by the protein-carbohydrate ratio. Products with more protein also develop more flavor (when protein is heated, hundreds of new flavor compounds are created via a process called the Maillard reaction). We also noticed that the winner contains a trace of sugar, more than its rivals, which may have contributed to better flavor. (Our winner adds rosemary extract as a preservative, but so did our two lowest-ranked brands; the rosemary adds little to no flavor.)

In terms of shape, our tasters preferred larger pearls, even if they were only incrementally bigger than others. Packaging may have also influenced our preferences. The airtightness of the packaging tracks with our rating of the contents: Our top two products are sold in jars, and the third- and fourth-place products are sold in plastic bags (with the fourth-place bag inside a cardboard box), while our lowest-ranked couscous is sold with the least airtight packaging, loose in a cardboard box, making it seem “stale.”

While we recommend most of the products we tasted, we’ll be buying our top-ranked couscous for its “rich and nutty” taste and “chewy but tender” texture.