You can’t get much farther out on the orbit of the city than northern Riverdale Avenue just before the Bronx becomes Yonkers. And you’d be hard put to find a drabber retail cluster than the Food Emporium Shopping Center. But here, across from an abandoned former eyeglass shop, you’ll find kosher wine’s action central: Skyview Wines & Spirits. When I visited the shop last Thursday, the pace was positively frenetic, as customers crowded the aisles to pick out wines for their Passover tables. In proprietor Jeff Saunders’s small office in the rear of the shop, the fax machine spewed out wine orders from all around the country, one of them, from a distant state, for more than $4,900.

No retail shop that I know of can match Skyview’s selection of more than 450 kosher bottlings from 15 countries. Nor, in most cases, can the shop’s prices be beaten. Looking for a bargain priced Israeli wine? Go for easy-drinking Mount Hermon red or white for $4.95 a half-bottle. Thinking big bucks and don’t care where the wine is sourced? How about Chateau de Valandraud, a tiny, trophy property in Saint Emilion much appreciated by critic Robert Parker, priced at $300 a bottle for the 2001 vintage? To acquire a bottle of Valandraud, you’ll need to ask Mr. Saunders to release a bottle from the private stash in his tiny office.

What makes a wine kosher? For starters, winemaking must be handled by observant Jews. Stainless steel tanks and oak barrels must be specially cleaned before filling. Fermentation yeasts must be natural and wine clarifiers may contain no products of animal origin such as gelatin or egg whites. If kosher wine is to be served by non-Jews, it must be flash-boiled, a process called mevushal. Many wines are kosher but not mevushal, since the process may impede the development of wines meant for aging in bottle. Behind many of the kosher wine strictures, which are dictated by rabbis rather than the Bible, is an ancient fear that a wine used for sacramental blessings, if of uncertain origin, might once have been used for pagan rites.

Tradition counts at Passover, and the familiar squat bottle of oozy-sweet Concord grape wine isn’t about to lose its place of honor at most Seder tables. But everything else about kosher wine has changed – and for the better. It started in 1972, when famed American oenologist Cornelius Ough suggested to a group of cooperative farmers on the Golan Heights that their cool climate and volcanic soils could be ideal for fine table wine. In 1984, the farmers, taking the name Golan Heights Winery, released their first red and white wines under the Yarden label. Made from such classic varieties as cabernet sauvignon, chardonnay, and riesling, they were dry and pure-fruited, and elegant rather than powerful. They were a far cry from the sacramental style kosher wines then dominant in Israel. Most strikingly, the kosher designation was moved from the front to the back of Yarden’s label. It was a way of declaring that the quality of the wine in the bottle, not its kosher seal, was reason enough to buy it.

Dozens of new wineries have sprung up in Israel since the late 1990s, most of them small but quality-driven. Even giant Carmel, founded by Baron Edmond de Rothschild in 1882, has emerged from long slumber. Some of its new covey of boutique wineries are worthy challengers to Yarden. A particular standout is Yatir Forest, from hillside vineyards near Arad. With its fleshy, sinuous texture, you won’t mistake this wine for firmer, more structured examples from Yarden.

As Yarden got up and running on the Golan Heights in the 1980s, a small kosher wine company called Herzog Wine Cellars was taking root in California. It is now the giant in its category, producing an array of wines under the Baron Herzog label ranging from white zinfandel priced under $6 to a special edition cabernet sauvignon from Napa’s prestigious Warnecke Vineyard that sells for $50. Last June, demonstrating that kosher wine is not a peripheral category, Herzog Wine Cellars opened a sprawling 77,000-square-foot winery, visitors’ center, and a restaurant called Tierra Sur in Oxnard, at the southern gateway to California wine country.

Between Israel and California, the poles of kosher wine, lie the traditonal wine zones of Europe. But high-quality kosher wine was only introduced there in 1988, when the Rothschild interests produced their first kosher wine in Bordeaux. Called Barons Rothschild, it is made at Chateau Clarke in the Haut-Medoc. Twenty-three Bordeaux wines, all kosher for Passover, are available this year at Skyview. You also can have your pick of wines from many other prestigious European wine appellations, ranging from Burgundy to Barolo. As Mr. Saunders says, “The kosher wine market has now built a bridge to the non-kosher fine wine market. The gap is gone.”

Skyview Wines & Spirits, 5681 Riverdale Ave., Riverdale, 718-601-8222, skyviewwines.com. Delivery to Manhattan is free for orders above $150.

Recommended Kosher Wines From Skyview

GOOSE BAY PINOT NOIR 2004, EAST COAST, NEW ZEALAND ($19.95) Light-bodied but filled with seductive red raspberry fruit. Almost jammy but hard to resist. A welcome, if belated, Kiwi kosher entry into the American market. Goose Bay’s Sauvignon Blanc ($17.99) is also a winner.

CASTEL “C” BLANC DU CASTEL 2003, ISRAEL ($34.95) Israel’s most buttery, almost butterscotchy chardonnay. Voluptuous as it is, it seems more burgundian than Californian. In 2003, “C” was a tad leaner than usual. From a deluxe winery nestled in the hills south of Jerusalem.

DALTON CABERNET SAUVIGNON 2004, MOUNT MERON, “TENTH ANNIVERSARY” ($39.95) Unusually nimble “cab,” animated by eucalyptus and mint flavors. Shows that higher-priced examples of this grape need not automatically be muscle-bound. Just 500 cases produced.

CHATEAU MALMAISON, MEDOC, 2000 ($29.95) Bordeaux wines from this epic vintage are getting scarce in the marketplace. Kosher versions are harder yet to find. This one is typical of the vintage: richly fruited, yet enlivened by firm tannins and acidity. A wine for the francophiles out there.

YARDEN “HEIGHTS” WINE ($19.95 PER HALF BOTTLE) A sweet but not syrupy sipper evoking apricot and orange blossom essences. Just right at the beginning of the meal with foie gras or at the end with plain sponge or pound cake. Made from late-harvested grapes that are frozen at the winery, then pressed so that water crystals fall away, leaving behind this nectar.